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Amazon ElastiCache User Guide

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1. REPLICATIONGROUP my repgroup My replication group creating CLUSTERID my redis primary API The following code can be used to create a Redis replication group when you already have an active Redis cluster that is not a member of any other replication group To create a replication group use the CreateReplicationGroup action with the following parameters ReplicationGroupId ReplicationGroupDescription e PrimaryClusterlId The following example creates a replication group named my repgroup with a primary cache cluster named my redis primary Example https elasticache us west 2 amazonaws com Action CreateReplicationGroup amp ReplicationGroupDescription My 20replication 20group amp ReplicationGroupId my repgroup amp PrimaryClusterId my redis primary amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 132 Amazon ElastiCache User Guide Adding a Read Replica To a Replication Group Adding a Read Replica To a Replication Group When the replication group has been created you can add a read replica cache cluster to it ElastiCache supports up to five re
2. VALUE mykey 0 28 This is the value for my key END To disconnect from the cache engine type the following quit Important To avoid incurring additional charges on your AWS account be sure to delete any AWS resources you no longer want after trying these examples API Version 2015 02 02 170 Amazon ElastiCache User Guide Managing Cache Subnet Groups Managing Cache Subnet Groups This section covers operations on cache subnet groups Cache subnet groups are required for cache clusters running inside of an Amazon Virtual Private Cloud VPC environment Topics e Creating a Cache Subnet Group p 171 e Assigning a Cache Subnet Group to a Cache Cluster p 172 e Modifying a Cache Subnet Group p 172 e Deleting a Cache Subnet Group p 174 Creating a Cache Subnet Group The following procedures show you how to create a cache subnet group called mycachesubnetgroup AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache In the left navigation pane click Cache Subnet Groups Click Create Cache Subnet Group In the Name box type a name for your cache subnet group In the Description box type a short description for your cache subnet group In the VPC ID box select the identifier for the VPC to be associated with this cache subnet group In the Availability Zone box select the
3. ccceceeeeee eee ee eee cece neces cece cece esse eseeseeseeseeseeseeseeeeeneeaeenes 193 Logging Amazon ElastiCache API Calls Using AWS CloudTrail cceeeceeeeeeeee eee eee eea een eea een eeaeenes 196 ElastiCache Information in CloudTrail ccceeeeeeeeenee eee eee eee eeeeeceeaeeceeeeeaeeseeseeeeeseeseeseeeeeaes 196 Understanding ElastiCache Log File Entries ccceeeeeceeee eee ee eter eee eters een een eens een eea een eeaes 197 Controlling ElastiCache Access with IAM cccceeeee teen eee ee nee ee eee e eta ee deen ee aeeaeeneeaeenes 200 About AMi ererig veoh enn Scud ana ea sand a AERA EE ESAERA and dea eeendd eh daa a ceeuanpheadeeeeraades 200 ElastiCache Security Groups and IAM 0 ceceee cece eect eee eee eee eee eens deans dete e ae ea ee aeeaeeaeeaeeaeeaees 201 ElastiCache Resources and IAM ccececenee eee nee eee teens nese een nea e acne cee aeea eed eaeeaeeaeeaeeaeeaeeaeeaeegs 201 ElastiCache Actions and IAM cccccceeeeec eee e tent cee e eee eee e eee e cece cece ceca e deca ede eca ede esa estan egies 201 Example Action Patterns nne ae niao decane dees R A nadia vanes A aS land ea EE aiai 202 ElastiCache Keysi mariemna ran E a a A e AE A E A ai 202 Example Policies for Elasti ath E noniriasir inian ae a eee O E ees 203 Failure to Retrieve Account Attributes 0 2 0 0 ieee cece eee ee eee eens ce ee eee eee ee esse eeeeseeseeseeeeeneeeees 204 Installing ElastiC
4. lt PurchaseReservedCacheNodesOfferingResponse xmlns http elasticache us west 2 amazonaws com doc 2013 06 15 gt lt PurchaseReservedCacheNodesOfferingResult gt lt ReservedCacheNode gt lt OfferingType gt Medium Utilization lt OfferingType gt lt CurrencyCode gt USD lt CurrencyCode gt lt RecurringCharges gt lt ProductDescription gt memcached lt ProductDescription gt lt ReservedCacheNodesOf feringId gt 649fd0c8 cf6d 47a0 bfa6 060f8e75e95 lt R servedCacheNodesOfferingId gt lt State gt payment pending lt State gt lt ReservedCacheNodeld gt myreservationID lt ReservedCacheNodeld gt lt CacheNodeCount gt 10 lt CacheNodeCount gt lt StartTime gt 2013 07 18T23 24 56 5772 lt StartTime gt lt lt lt Duration gt 31536000 lt Duration gt FixedPrice gt 123 0 lt FixedPrice gt UsagePrice gt 0 123 lt UsagePrice gt lt CacheNodeType gt cache ml small lt CacheNodeType gt lt ReservedCacheNode gt lt PurchaseReservedCacheNodesOfferingResult gt lt ResponseMetadata gt lt Request Id gt 7 099901 29cf 1lel bd06 6fe008f046c3 lt RequestId gt lt ResponseMetadata gt lt PurchaseReservedCacheNodesOf feringResponse gt Using Amazon SNS Notifications with ElastiCache You can configure ElastiCache to send notifications for important cluster events using Amazon Simple Notification Service Amazon SNS In these examples you will configure a cl
5. API Version 2015 02 02 13 Amazon ElastiCache User Guide Step 2 Launch a Redis Cluster 2 3 4 e To launch this cluster in a VPC recommended select a VPC subnet group To launch this cluster outside a VPC click Not in VPC The cluster will be launched in the AWS public cloud Availability Zones From the drop down list select the availability zone for this cluster To have ElastiCache select the zone for you select No Preference Cache Security Groups or VPC Security Groups Select the security groups for this cluster If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more information about Amazon VPC security groups see htip docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Security p 5 and Managing Cache Security Groups p 175 In the Backup section of the Configure Advanced Settings page specify settings as shown following Enable Automatic Backups To schedule regular automatic backups of your cluster check this check box e Unchecked Default Leaving this unchecked means that ElastiCache will not schedule automatic backups of this cluster If you want a backup you must create a manual backup For more information see Creating a Manual Snapshot p 146 Checked Checking this checkbox causes ElastiCache to schedule regular au
6. API Version 2015 02 02 69 Amazon ElastiCache User Guide Modifying Tags on Your ElastiCache Resource The ResourceName parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt https elasticache us west 2 amazonaws com Action ListTagsForResource amp ResourceName arn aws elasticache us west 2 0123456789 cluster myCluster SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Version 2015 02 02 amp Timestamp 20150202T1923172 amp X Amz Credential lt credential gt Modifying Tags on Your ElastiCache Resource You can modify the existing tags on an ElastiCache resource by using the ElastiCache management console AWS CLI or ElastiCache API Topics ElastiCache Console p 70 e AWS CLI p 71 ElastiCache API p 71 ElastiCache Console You can use the ElastiCache management console to modify existing tags on a resource To modify a tag on an ElastiCache resource using the ElastiCache management console 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache Depending what ElastiCache resource you want to modify a tag on click either Clusters or Snapshots Select the ElastiCache resource for which you want to modify a tag Click Manage Tags at the top of the screen To modify a tag s value either de
7. API Version 2015 02 02 59 Amazon ElastiCache User Guide ElastiCache and Amazon Virtual Private Cloud security group which in turn specifies the Amazon EC2 instances allowed The security group can be associated with your cluster at the time of creation or using a ModifyCacheCluster command Important IP range based access control is currently not enabled for clusters All clients to a cluster must be within the EC2 network and authorized via security groups as described previously For more information about working with security groups see Managing Cache Security Groups p 175 ElastiCache and Amazon Virtual Private Cloud Note ElastiCache is fully integrated with Amazon Virtual Private Cloud VPC For ElastiCache users this means the following If your AWS account supports only the EC2 VPC platform ElastiCache will always launch your cluster in a VPC If you re new to ElastiCache your clusters will be deployed into a VPC A default VPC will be created for you automatically If you have a default VPC and don t specify a subnet when you launch a cluster the cluster launches into your default VPC You can launch clusters into your default VPC without needing to know anything about Amazon VPC Your experience with clusters that you launch is the same whether you have a default VPC or not For more information see Detecting Your Supported Platforms and Whether You Have a Default VPC With Amazon Virtual Private C
8. FixedPrice gt 1820 0 lt FixedPrice gt ProductDescription gt memcached lt ProductDescription gt UsagePrice gt 0 368 lt UsagePrice gt ReservedCacheNodesOf feringId gt 438012d3 4052 4cc7 b2e3 8d3372e0e706 lt ReservedCacheNodesOfferingId gt lt CacheNodeType gt cache ml large lt CacheNodeType gt lt ReservedCacheNodesOffering gt lt ReservedCacheNodesOf fering gt output omitted lt ReservedCacheNodesOffering gt lt ReservedCacheNodesOfferings gt lt DescribeReservedCacheNodesOfferingsResult gt lt ResponseMetadata gt lt Request Id gt 5e4ec40b 2978 11lel 9e6d 771388d6ed6b lt RequestId gt lt ResponseMetadata gt lt DescribeReservedCacheNodesOfferingsResponse gt Some of the output has been omitted for brevity Purchasing a Reserved Cluster The following example shows how to purchase a reserved cluster offering Important Following the examples in this section will incur charges on your AWS account API Version 2015 02 02 109 Amazon ElastiCache User Guide Managing Reserved Nodes AWS Management Console This example shows purchasing a specific reserved cache node offering 649fd0c8 cf6d 47a0 bfa6 060f8e75e95fF with a reserved cache node ID of myreservationID 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache In the navigation list click the Reserved Cache Nodes link
9. In the navigation list click the Reserved Cache Nodes link Click the Purchase Reserved Cache Node button From the Product Description drop down list box select the engine Memcached or Redis To determine the available offerings make selections from the next 3 drop down list boxes oP oN Cache Node Type Term Offering Type Once you make these selections the cost per node and total cost of your selections is shows in the Purchase Reserved Cache Nodes wizard 6 Click Cancel to avoid purchasing these nodes and incurring charges CLI To get pricing and information about available reserved cluster offerings type the following command at a command prompt PROMPT gt elasticache describe reserved cache nodes offerings headers This call returns output similar to the following OFFERING OfferingId Class Duration Fixed Pric Usage Pric Description Offering Type OFFERING 438012d3 4052 4cc7 b2e3 8d3372e0e706 cache ml large ly 1820 00 USD 0 368 USD memcached Medium Utilization OFFERING 649fd0c8 cf6 d 47a0 bfa6 060f8e75e95F cache ml small ly 227 50 USD 0 046 USD memcached Medium Utilization OFFERING 123456cd ablc 47a0 bfa6 12345667232f cache ml small ly 162 00 USD 0 00 USD memcached Heavy Utilization Recurring Charges Amount Currency Frequency Recurring Charges 0 123 USD Hourly OFFERING 123456cd ablc 37a0 bfa6 12345667232d cache ml large ly 700
10. client output buffer limit pubsub hard limit client output buffer limit pubsub soft limit client output buffer limit pubsub soft seconds client output buffer limit slave hard limit Default Type 0 integer 0 integer 0 integer 33554432 integer 8388608 integer 60 integer 268435456 integer Modi fi able Yes Yes Yes Yes Yes Yes No Description If a client s output buffer reaches the specified number of bytes the client will be disconnected The default is zero no hard limit If a client s output buffer reaches the specified number of bytes the client will be disconnected but only if this condition persists for client output buffer lim it normal soft seconds The default is zero no soft limit If a client s output buffer remains at client output buffer limit normal soft limit bytes for longer than this number of seconds the client will be dis connected The default is zero no time limit For Redis publish subscribe cli ents If a client s output buffer reaches the specified number of bytes the client will be disconnec ted For Redis publish subscribe cli ents If a client s output buffer reaches the specified number of bytes the client will be disconnec ted but only if this condition per sists for client output buf fer limit pubsub soft seconds For Redis publish subscribe cli ents If a client s output buffer re mains at clie
11. ec2 DescribeAvailabilityZones ec2 DescribeVpcs cloudwatch GetMetricStatistics cloudwatch DescribeAlarms sns ListTopics sns ListSubscriptions Resource Add the two additional actions stated above to get the following policy document that will give permission to the console to invoke the needed actions Version 2012 10 17 Statement Effect Allow Action elasticache ec2 DescribeAvailabilityZones ec2 DescribeVpcs ec2 DescribeAccountAttributes ec2 DescribeSecurityGroups cloudwatch GetMetricStatistics cloudwatch DescribeAlarms sns ListTopics sns ListSubscriptions Resource For information about updating IAM policies see Managing IAM Policies API Version 2015 02 02 205 Amazon ElastiCache User Guide Installing the ElastiCache Cluster Client for PHP Installing ElastiCache Cluster Clients Topics e Installing the ElastiCache Cluster Client for PHP p 206 e Installing the ElastiCache Cluster Client for NET p 210 Installing the ElastiCache Cluster Client for PHP Topics Downloading the Installation Package p 206 e Installation Steps for New Users p 207 For Users Who Already Have php memcached Extension Installed p 210 Removing the PHP Cluster Client p 210 This section describes how to install update and remove the PHP components for the ElastiCache Cluster Client on Amazon
12. Amazon ElastiCache User Guide API Version 2015 02 02 nae mazon webservices ae bc p mia z975 m Amazon ElastiCache User Guide Amazon ElastiCache User Guide Copyright 2015 Amazon Web Services Inc and or its affiliates All rights reserved AWS services or capabilities described in AWS Documentation may vary by region location Click Getting Started with Amazon AWS to see specific differences applicable to the China Beijing Region Amazon ElastiCache User Guide Table of Contents What Is Amazon ElastiCache cccececc ete nee eee eee eee renee ene renee rede e aed aE aR E Ea desea hii anadi 1 Amazon ElastiCache Videos ceiien aeriene iaa ee eee een eee een eee esate a een eee aia in aaaea eaaa aii esate 2 IntVOdUCtOry VIJES risiini taniand cdsnomncs bandh da naedaads winnie ssesleedensaadbowesassedsrteantuhddeatteds 2 AdVvanCed VidG6OS eisiaa bie cea E Ea A ER Daa e DE aAa EAE E E A EEEE 2 Are You a First Time ElastiCache User ccceeeeeee eee e eter ener teeter ee ee etre een eea ee eea een eea een eeaes 3 Data Mod l siti Pes oct sie bs hisecensidveaesthabondessabanewiacbecauesebs teed edus ist vet eee techs wgandbstees shes deese baeeetaeeocy 4 Cache NOGSS a hice echoes pea tene a sets boue E a EEE E E E 4 Cache CIUSTET sisi asiedccie anione EE E EAE A A E E E diene AE A EEE E E 4 Cache Parameter Groups 0 ccseceeenee eee ee teeta ee eee tenet a een een ee nese tenes a eea
13. Syntax config sub command key Options Name Description Required sub com The sub command used to interact with a cache node For Auto Discov Yes mand ery this sub command is get key The key under which the cluster configuration is stored For Auto Discov Yes ery this key is named cluster To get the cluster configuration information use the following command config get cluster Cache Engine Version Lower Than 1 4 14 To get the cluster configuration information use the following command get AmazonElastiCache cluster Note We recommend that you do not tamper with the AmazonElastiCache cluster key since this is where the cluster configuration information resides If you do overwrite this key then the client may be incorrectly configured for a brief period of time no more than 15 seconds before ElastiCache automatically and correctly updates the configuration information Output Format Whether you use config get cluster orget AmazonElastiCache cluster the reply consists of two lines The version number of the configuration information Each time a node is added or removed from the cache cluster the version number increases by one A list of cache nodes Each node in the list is represented by a hostname ip address port group and each node is delimited by a space A carriage return and a linefeed character CR LF appears at the end of each line A cache cluster containing
14. T ERGROUP default memcachedl 4 memcached1 4 for memcached1 4 Default parameter group API Call DescribeCacheParameterGroups with no parameters API Version 2015 02 02 157 Amazon ElastiCache User Guide Viewing Parameter Values for a Cache Parameter Group Example https elasticache us west 2 amazonaws com Action DescribeCacheParameterGroups amp MaxRecords 100 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This command should return a response similar to the following lt DescribeCacheParameterGroupsResponse xmlns http elasticache amazon aws com doc 2013 06 15 gt lt DescribeCacheParameterGroupsResult gt lt CacheParameterGroups gt lt CacheParameterGroup gt lt CacheParameterGroupName gt default memcached1 4 lt CacheParameterGroupName gt lt CacheParameterGroupFamily gt memcached1 4 lt CacheParameterGroupFamily gt lt Description gt Default parameter group for memcached1 4 lt Description gt lt CacheParameterGroup gt lt CacheParameterGroups gt lt DescribeCacheParameterGroupsResult gt lt ResponseMetadata gt lt RequestId gt 3540cc
15. We strongly recommend that you use an Amazon S3 bucket that is in the same region as your ElastiCache cluster This approach will ensure the highest data transfer speed when ElastiCache reads your Redis snapshot from Amazon S3 It is also important that you note the S3 path for the rdb file For example if my bucket name was myBucket and the path was myFolder redis rdb you would enter API Version 2015 02 02 151 Amazon ElastiCache User Guide Migrating Your Redis Cluster to ElastiCache myBucket myFolder redis rdb You need this path to seed the new cluster with the data in this snapshot Grant ElastiCache Read Access to the rdb File The next step is to grant ElastiCache read access to the snapshot file you copied to Amazon S3 To grant ElastiCache read access to the snapshot copied to Amazon S3 1 oar wn Sign in to the AWS Management Console and open the Amazon S3 console at https console amazonaws cn s3 Click All Buckets and then click the name of the Amazon S3 bucket that contains your rdb file Click the name of the folder that contains your rdb file Click the name of your rdb file click the Actions drop down menu and then select Properties Click Permissions and then click Add more permissions In the Grantee box enter this canonical ID b14d6al25bd 69854ed8ef2e71d8a20b7c490 252229b806e514966e490b8d83 Click Open Download and then click Save Seed a Cluster With rdb File Data Now you are
16. You can use Amazon VPC security groups to help secure the ElastiCache clusters and Amazon EC2 instances in your Amazon VPC Security groups act like a firewall at the instance level not the subnet level Clusters in an Amazon VPC can be accessed by Amazon EC2 instances in the same Amazon VPC If these Amazon EC2 instances are deployed in a public subnet with associated Elastic IPs you can access the Amazon EC2 instances via the Internet Note We strongly recommend that you use DNS names to connect to your cache nodes as the underlying IP address can change if you reboot the cache node For more information about using ElastiCache with Amazon VPC see Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 Amazon VPC Documentation Amazon VPC has its own set of documentation to describe how to create and use your Amazon VPC The following table gives links to the Amazon VPC guides API Version 2015 02 02 62 Amazon ElastiCache User Guide Cache Engine Version Management Description Documentation How to get started using Amazon VPC Amazon VPC Getting Started Guide How to use Amazon VPC through the AWS Man Amazon VPC User Guide agement Console Complete descriptions of all the Amazon VPC Amazon EC2 Command Line Reference commands the Amazon VPC commands are part of the Amazon EC2 reference Complete descriptions of the Amazon VPC API Amazon EC2 API Reference actions data types and errors the Amazo
17. amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Modifying an Existing Redis Replication Group AWS Management Console The following procedure modifies an existing replication group to enable Multi AZ You can use the same process to make other modifications to a replication group To modify an existing replication group 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Replication Groups API Version 2015 02 02 135 Amazon ElastiCache User Guide Deleting a Read Replica 3 To select the replication group to modify from the list of replication groups click the name of the replication group you want to modify 4 Click Modify 5 Select Yes for Multi AZ and then click Modify The status of the replication group will change to modifying The modifications can take several minutes When the replication group s status returns to available the modifications are complete and the replication group is ready to use CLI The following CLI command modifies an existing Redis replication group to enable Multi AZ You can us
18. amp Description My 20cache 20security 20group amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Listing Available Cache Security Groups You can list which cache security groups have been created for your AWS account The following procedures show you how to list the available cache security groups for your AWS account AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Security Groups The available cache security groups appear in the Cache Security Groups list CLI Use the command elasticache describe cache security groups to list all available cache security groups for your AWS account PROMPT gt elasticache describe cache security groups API Call DescribeCacheSecurityGroups with no parameters API Version 2015 02 02 176 Amazon ElastiCache User Guide Viewing a Cache Security Group Example https elasticache us west 2 amazonaws com Action DescribeCacheSecurityGroups amp MaxRecords 100 amp Version 2014 12 01 amp SignatureV
19. amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Creating a Manual Snapshot You can create a manual snapshot at any time You must provide the name of the source cluster and a name for the snapshot The following procedures show you how to create a manual snapshot Topics AWS Management Console p 146 e CLI p 147 API p 147 Exporting a Manual Snapshot p 147 AWS Management Console To create a manual snapshot using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Snapshots At the top of the screen click Create Snapshot 4 Inthe Create Cache Snapshot dialog w a From the Cache Cluster drop down list select the name of the source cluster b In the Snapshot Name text box type a name for the snapshot c Click Create The new snapshot will be listed in the list of snapshots Its status will be creating while it is being created This process can take several minutes When the status changes to available it is created and you can use it API Version 2015 02 02 146
20. e aws SecureTransport lo check whether the request was sent using SSL For services that use only SSL such as Amazon RDS and Amazon Route 53 the aws SecureTransport key has no meaning aws SourceArn To check the source of the request using the Amazon Resource Name ARN of the source This value is available for only some services For more information see Amazon Resource Name ARN under Element Descriptions in the Amazon Simple Queue Service Developer Guide e aws SourceIp To check the IP address of the requester Note that if you use aws SourceIp and the request comes from an Amazon EC2 instance the public IP address of the instance is evaluated aws UserAgent To check the client application that made the request e aws userid To check the user ID of the requester e aws username Io check the user name of the requester if available Note Key names are case sensitive Example Policies for ElastiCache This section shows a few simple policies for controlling user access to Amazon ElastiCache Note In the future ElastiCache might add new actions that should logically be included in one of the following policies based on the policy s stated goals Example 1 Allow a Network Admin group to only be able to access the APIs related to ElastiCache security groups In this example we create a policy that gives access to the relevant actions and attach it to the group The resource is stated as because
21. gt e we ee o ao GRENEDAN JN Auto Minor Version Upgrade Yes Notification ARN Disabled Cache Subnet Group Security Group s default active Cache Parameter Group default memcached1 4 in sync Maintenance Window tvec01 30 tue 02 30 Replication Group WA 3 Click the Delete button Cache Cluster mycacheciuster Cache Cluster Details Cache Cluster D mycachectuster Status available Creation Time July 30 2014 9 45 59 Cache Node Type cache r3 large Engine memcached Engine Version 1 4 14 Availability Zone Multiple Number of Cache Nodes 8 Number of Nodes Pending Creation NIA Nodes Pending Deletion onfiguraton Endpoint 0001 0003 0007 e w ee e e Yes Disabled Auto Minor Version Upgrade Notification ARN Cache Subnet Group Security Group s default active Cache Parameter Group defaultmemcachedt Maintenance Window tue 04 30 tue 02 30 The status of the selected nodes changes to pending delete If you selected Apply Immediately Yes after a few moments the status changes to deleting If it doesn t refresh your browser screen Delete Node Are you sure you want to delete these Cache Nodes 0001 0003 Apply Immediately No Yes CLI 1 Usethe command elasticache describe cach cae cluster to display a list of nodes for a cluster as in the following example and note the identifiers of the nodes y
22. Description The size in bytes of the primary node backlog buffer The backlog is used for recording updates to data at the primary node When a read replica connects to the primary it attempts to perform a partial sync psync where it ap plies data from the backlog to catch up with the primary node If the psync fails then a full sync is required The minimum value for this para meter is 16384 The number of seconds that the primary node will retain the back log buffer Starting from the time the last replica node disconnec ted the data in the backlog will remain intact until repl backlog ttl expires If the replica has not connected to the primary within this time then the primary will re lease the backlog buffer When the replica eventually reconnects it will have to perform a full sync with the primary If this parameter is set to 0 then the backlog buffer will never be released Represents the timeout period in seconds for Bulk data transfer during syn chronization from the read rep lica s perspective Primary node timeout from the replica s perspective e Replica timeout from the primary node s perspective The following table shows the Redis 2 6 13 parameters that ElastiCache supports API Version 2015 02 02 51 Amazon ElastiCache User Guide Parameters for Redis Name activerehashing appendonly appendfsync able Default Type Modi fi yes string Yes no st
23. Example https elasticache us west 2 amazonaws com Action ModifyCacheCluster amp ApplyImmediately fals amp CacheClusterId my cache cluster amp NotificationTopicStatus inactive amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Deleting a Cache Cluster As soon as your cluster becomes available you re billed for each hour or partial hour that you keep the cluster running even if the cluster is idle When you ve decided that you no longer need the cluster you can delete it Deleting a cluster requires you to identify the cluster you want to remove Before you continue be certain you want to delete this cluster You cannot reverse the action once the delete process begins The following procedures show you how to delete a cluster AWS Management Console To delete a cluster As soon as the cluster status changes to deleted you stop incurring charges for that cluster 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 Inthe ElastiCache console dashboard click Cache Clusters 3 Inthe list of clusters to select the
24. In this example you will create an Amazon VPC with a private subnet for each Availability Zone AWS Management Console To create an ElastiCache cache cluster inside an Amazon Virtual Private Cloud 1 Signin to the AWS Management Console and open the Amazon VPC console at hitps console www amazonaws cn vpc 2 Create anew Amazon VPC by using the Amazon Virtual Private Cloud wizard a Inthe navigation list click VPC Dashboard API Version 2015 02 02 164 Amazon ElastiCache User Guide Creating a Virtual Private Cloud VPC Click Start VPC Wizard In the Amazon VPC wizard click VPC with Public and Private Subnets and then click Next On the VPC with Public and Private Subnets page keep the default options and then click Create VPC In the confirmation message that appears click Close Confirm that there are two subnets in your Amazon VPC a public subnet and a private subnet These subnets are created automatically a b In the navigation list click Subnets In the list of subnets find the two subnets that are in your Amazon VPC Subnet ID State VPC ID subnet 5bf5e639 2 available vpc d3a77cb6 10 0 1 251 subnet 58f5e63a available vpc d3a77cb6 ic 250 The public subnet will have one fewer available IP address because the wizard creates an Amazon EC2 NAT instance and an Elastic IP address for which Amazon EC2 rates apply for outbound communication to the Internet from your private subnet
25. PROMPT gt elasticache delete cache subnet group mycachesubnetgroup This command produces no output API Call DeleteCacheSubnetGroup with the following parameter e CacheSubnetGroupName mycachesubnetgroup Example https elasticache us west 2 amazonaws com Action DeleteCacheSubnetGroup amp CacheSubnetGroupName mycachesubnetgroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 174 Amazon ElastiCache User Guide Managing Cache Security Groups Managing Cache Security Groups Note Cache security groups are only applicable to cache clusters that are not running in an Amazon Virtual Private Cloud environment VPC For more information on using ElastiCache with Amazon VPCs see Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 A cache security group allows you to control access to your cache clusters A cache security group acts like a firewall controlling network access to your cache cluster By default network access is disabled for a new cache security group you must specifically authorize access to an Amazon EC2 security group after the c
26. Prerequisites 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard Step 1 Select the Redis Engine Before you proceed be sure you have completed the Prerequisites section To select your cluster s engine 1 On the Select Engine screen click the Redis tab SFA 2 Click Next API Version 2015 02 02 12 Amazon ElastiCache User Guide Step 2 Launch a Redis Cluster Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Redis Engine To configure your cluster s specifications and details 1 Inthe Cluster Specifications section of the Specify Cluster Details page specify settings as shown following a Engine Redis b Engine Version From the list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version c Cache Port Type a new port number for your cluster or leave it at its default value For Redis the default port is 6379 d Parameter Group From the list select a parameter group for this cluster Parameter groups control the run time parameters of your cluster For more information on parameter groups see Node Type Specific Parameters for Redis p 57 e Enable Replication To c
27. p 57 S3 Location of Redis RDB file Amazon S3 location of the rdb file used to seed this cluster If this is left blank this cluster will not be seeded upon creation For more information on snapshots and seeding a Redis cluster see Backup and Restore for Redis Clusters p 38 and Migrating Your Redis Cluster to ElastiCache p 151 3 Click Next API Version 2015 02 02 140 Amazon ElastiCache User Guide Enabling Automatic Snapshots on a New Cluster Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details To configure your cluster s advanced settings 1 Inthe Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this cluster associated with e To launch this cluster in a VPC recommended select a VPC subnet group To launch this cluster outside a VPC click Not in VPC The cluster will be launched in the AWS public cloud Availability Zones From the drop down list select the availability zone for this cluster To have ElastiCache select the zone for you select No Preference Cache Security Groups or VPC Security Groups Select the security groups for this cluster If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more informatio
28. you can always create a custom cache parameter group and assign it to your cluster at any time Redis 2 8 19 Added Parameters For Redis 2 8 19 there are no additional parameters supported Redis 2 8 6 Added Parameters For Redis 2 8 6 the following additional parameters are supported Name Default Type Modifi Description able min slaves max lag 10 integer Yes The number of seconds within which the primary node must re ceive a ping request from a read replica If this amount of time passes and the primary does not receive a ping then the replica is no longer considered available If the number of available replicas drops below min slaves to write then the primary will stop accept ing writes at that point If either this parameter or min slaves to write is 0 then the primary node will always accept writes requests even if no replicas are available API Version 2015 02 02 48 Amazon ElastiCache User Guide Parameters for Redis Name Default Type Modifi Description able min slaves to write 0 integer Yes The minimum number of read replicas which must be available in order for the primary node to accept writes from clients If the number of available replicas falls below this number then the primary node will no longer accept write requests If either this parameter or min slaves max lag is 0 then the primary node will always accept writes requests even if no replicas are available A
29. 00 USD 0 00 USD memcached Heavy Utilization Recurring Charges Amount Currency Frequency Recurring Charges 1625 USD Hourly OFFERING 123456cd ablc 17d0 bfa6 12345667234e cache ml xlarge ly 4242 00 USD 2 42 USD memcached Light Utilization API To get pricing and information about available reserved cluster offerings call the DescribeReservedCacheNodesOfferings action API Version 2015 02 02 108 Amazon ElastiCache User Guide Managing Reserved Nodes Example https elasticache us west 2 amazonaws com Action DescribeReservedCacheNodesOfferings amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This call returns output similar to the following lt DescribeReservedCacheNodesOfferingsResponse xmlns http elasticache us west 2 amazonaws com doc 2013 06 15 gt lt DescribeReservedCacheNodesOfferingsResult gt lt ReservedCacheNodesOfferings gt lt ReservedCacheNodesOf fering gt lt Duration gt 31536000 lt Duration gt lt OfferingType gt Medium Utilization lt OfferingType gt lt CurrencyCode gt USD lt CurrencyCode gt lt RecurringCharges gt lt lt lt lt
30. 10 0 0 0 24 tig 7 EC2 Instance 10 0 0 6 x x x x EIP Pe a TTT E 7 asesor The Amazon VPC is an isolated portion of the AWS cloud that is assigned its own block of IP addresses An Internet gateway connects your Amazon VPC directly to the Internet and provides access to other AWS resources such as Amazon Simple Storage Service Amazon S3 that are running outside your Amazon VPC An Amazon VPC subnet is a segment of the IP address range of an Amazon VPC where you can isolate AWS resources according to your security and operational needs A routing table in the Amazon VPC directs network traffic between the subnet and the Internet The Amazon VPC has an implied router which is symbolized in this diagram by the circle with the R An Amazon VPC security group controls inbound and outbound traffic for your ElastiCache clusters and Amazon EC2 instances API Version 2015 02 02 61 Amazon ElastiCache User Guide Prerequisites You can launch an ElastiCache cluster in the subnet The cache nodes have private IP addresses g from the subnet s range of addresses E You can also launch Amazon EC2 instances in the subnet Each Amazon EC2 instance has a private IP address from the subnet s range of addresses The Amazon EC2 instance can connect to any cache node in the same subnet Tel For an Amazon EC2 instance in y
31. API p 132 sections of this topic If on the other hand you need to create a replication group from scratch the best way to do that is to create the primary cluster replication group and secondary clusters at the same time from Cache Clusters Launch Cache Cluster using the AWS Management Console This is the subject of this topic API Version 2015 02 02 127 Amazon ElastiCache User Guide Creating a Redis Replication Group ElastiCache supports replication when you use the Redis engine To monitor the latency between when data is written to a Redis read write primary cluster and when it is propagated to a read only secondary cluster ElastiCache adds to the cluster a special key Elast iCacheMasterReplicationTimestamp which is the current Universal Coordinated Time UTC time Because a Redis cluster might be added to a replication group at a later time this key is included in all Redis clusters even if initially they are not members of a replication group To create a multi cluster Redis replication group concurrently with creating the primary cluster do the following Prerequisites 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard Step 1 Select the Redis Engine Before you proceed be sure you have completed the Prerequisites sect
32. Amazon ElastiCache User Guide Creating a Manual Snapshot CLI To create a manual snapshot use the elasticache create snapshot command The following example creates a snapshot of a cluster named my redis primary PROMPT gt elasticache create snapshot my manual snapshot cache cluster id my redis primary API To create a manual snapshot use the CreateSnapshot action with the following parameters e CacheClusterlId e SnapshotName The following example creates a manual snapshot named my manual snapshot from a cluster named my redis primary Example https elasticache us west 2 amazonaws com Action CreateSnapshot amp CacheClusterId my redis primary amp SnapshotName my manual snapshot amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Exporting a Manual Snapshot Currently Amazon ElastiCache does not allow direct access to ElastiCache snapshot rdb files If you need to export your data to an external rdb snapshot which you can access following is a procedure that will create a snapshot in your self managed Amazon Elastic Compute Cloud Amazon EC2 environment Because you are working outside o
33. Available IPs Tip Make a note of your two subnet identifiers and which is public and private You will need this information later when you launch your cache clusters and add an Amazon EC2 instance to your Amazon VPC Create an Amazon VPC security group You will use this group for your cache cluster and your Amazon EC2 instance a d Still in the Amazon VPC Management console in the left navigation pane click Security Groups Click Create Security Group Type a name and a description for your security group in the corresponding boxes In the VPC box click the identifier for your Amazon VPC Create Security Group Cancel x Name my vpc security group Description Testing VPC vpc d3a77cb6 Cancel Yes Create k 4 When the settings are as you want them click Yes Create Define a network ingress rule for your security group This rule will allow you to connect to your Amazon EC2 instance using Secure Shell SSH a b In the navigation list click Security Groups Find your security group in the list and then click it API Version 2015 02 02 165 Amazon ElastiCache User Guide Creating a Cache Subnet Group C d Under Security Group click the Inbound tab In the Create a new rule box click SSH and then click Add Rule Click Apply Rule Changes Now you are ready to create a cache subnet group and launch a cache cluster in your Amazon VPC Creating a Cache S
34. Click the Purchase Reserved Cache Node button Select the cache node type from the Product Description drop down list box Select the cache node class from the Cache Node Class drop down list box Select length of time you want the cache node reserved from the Term drop down list box Select the offering type from the Offering Type drop down list box You can optionally enter a reserved cache node ID in the Reserved Cache Node ID text box Note The Reserved Cache Node ID is an unique customer specified identifier to track this reservation If this box is left blank ElastiCache automatically generates an identifier for the reservation 9 Click the Next button Oo eo Ew NM The Purchase Reserved Cache Node dialog box shows a summary of the reserved cache node attributes that you ve selected and the payment due 10 Click the Yes Purchase button to proceed and purchase the reserved cache node Important When you click Yes Purchase you incur the charges for the reserved nodes you selected To avoid incurring these charges click Cancel CLI The following example shows purchasing a specific reserved cluster offering 649fd0c8 cf6d 47a0 bfa6 060f8e75e95f with a reserved cluster ID of myreservationID Type the following command at a command prompt PROMPT gt elasticache purchase reserved cache nodes offering 649fd0c8 cf6d 47a0 bfa6 060f8e75e95f i myreservationID The command returns output similar to the fol
35. Console You can enable Redis Multi AZ when you create a new cache cluster if You will select Redis as your cache cluster engine e Your cache cluster will have one or more read replicas To enable Redis Multi AZ when creating a new cache cluster using the console see Creating a Redis Multiple Cluster Replication Group p 127 To enable Multi AZ for an existing Redis replication group using the console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Replication Groups 3 Click to select the box next to the replication group for which you want to enable Multi AZ and click Modify 4 To enable Multi AZ select the Yes radio button behind Multi AZ Note Before you can enable Multi AZ the replication group must have at least one active read replica If the replication group does not have at least one active read replica the radio buttons for Multi AZ are disabled 5 Click Modify 6 Wait until the modification tasks finish and the replication group s status is available Enabling Redis Multi AZ Using the ElastiCache CLI You can use the ElastiCache CLI to enable Redis Multi AZ for a new or existing replication group API Version 2015 02 02 35 Amazon ElastiCache User Guide Enabling Redis Multi AZ Using the ElastiCache CLI to Enable Redis Multi AZ for a New Replication Group The following example creates
36. EC2 instances For more information about Auto Discovery see Node Auto Discovery Memcached p 116 For sample PHP code to use the client see Using the ElastiCache Cluster Client for PHP p 119 Downloading the Installation Package To ensure that you use the correct version of the ElastiCache Cluster Client for PHP you will need to know what version of PHP is installed on your Amazon EC2 instance You will also need to know whether your Amazon EC2 instance is running a 64 bit or 32 bit version of Linux To determine the PHP version installed on your Amazon EC2 instance At the command prompt run the following command php v The PHP version will be shown in the output as in this example API Version 2015 02 02 206 Amazon ElastiCache User Guide Installation Steps for New Users PHP 5 4 10 cli built Jan 11 2013 14 48 57 Copyright c 1997 2012 The PHP Group Zend Engine v2 4 0 Copyright c 1998 2012 Zend Technologies To determine your Amazon EC2 AMI architecture 64 bit or 32 bit 1 2 3 Sign in to the AWS Management Console and open the Amazon EC2 console at https console amazonaws cn ec2 In the Instances list click your Amazon EC2 instance In the Description tab look for the AMI field A 64 bit instance should have x86_64 as part of the description for a 32 bit instance look for i386 or i686 in this field You are now ready to download the ElastiCache C
37. ElastiCache User Guide ElastiCache is a web service that makes it easy to set up manage and scale a distributed in memory cache environment in the cloud It provides a high performance resizable and cost effective caching solution while removing the complexity associated with deploying and managing a distributed cache environment With ElastiCache you can quickly deploy your cache environment without having to provision hardware or install software You can choose from Memcached or Redis protocol compliant cache engine software and let ElastiCache perform software upgrades and patch management for you automatically For enhanced security ElastiCache runs in the Amazon Virtual Private Cloud Amazon VPC environment giving you complete control over network access to your cache cluster With just a few clicks in the AWS Management Console you can add resources to your ElastiCache environment such as additional nodes or read replicas to meet your business needs and application requirements Existing applications that use Memcached or Redis can use ElastiCache with almost no modification your applications simply need to know the host names and port numbers of the ElastiCache nodes that you have deployed The ElastiCache Auto Discovery feature lets your applications identify all of the nodes in a cache cluster and connect to them rather than having to maintain a list of available host names and port numbers in this way your applications are eff
38. ElastiCache console ElastiCache API or the AWS CLI to create snapshots of your ElastiCache for Redis clusters You can then use these snapshots at any time to preseed new ElastiCache for Redis clusters This capability covers the majority of use cases However in rare cases you might need access to the actual rdb file Currently Amazon ElastiCache does not allow direct access to the snapshot files If you need to export your data to an external rdb snapshot see Exporting a Manual Snapshot p 147 Note At this time backup and restore is supported only for clusters running Redis Backup and restore is not supported on cache t1 and cache t2 instance types Topics Enabling Automatic Snapshots on a New Cluster p 139 Enabling Automatic Snapshots for an Existing Cluster p 143 Enabling Automatic Snapshots for a Replication Group p 144 Creating a Manual Snapshot p 146 Displaying a List of Snapshots p 148 Copying a Snapshot p 148 Restoring a Snapshot to a New Cluster p 149 Migrating Your Redis Cluster to ElastiCache p 151 Deleting Snapshots p 153 Enabling Automatic Snapshots on a New Cluster The following sections contain procedures showing you how to enable automatic snapshots when you create a new Redis cluster AWS Management Console To enable snapshots when creating a Redis cluster check the Enable Automatic Backups check box and specify a nonzero number of days to retain the backups in substep 2
39. For Users Who Already Have php memcached Extension Installed To update the php memcached installation 1 Remove the previous installation of the Memcached extension for PHP 2 Install the new ElastiCache php memcached extension as described previously in Installation Steps for New Users p 207 Removing the PHP Cluster Client 1 Remove the php memcached extension sudo pecl uninstall __uri AmazonElastiCacheClusterClient 2 Remove the memcached ini file added in the appropriate directory as indicated in the previous installation steps Installing the ElastiCache Cluster Client for NET You can find the ElastiCache NET Cluster Client code as open source at https github com awslabs elasticache cluster config net This section describes how to install update and remove the NET components for the ElastiCache Cluster Client on Amazon EC2 instances For more information about auto discovery see Node Auto Discovery Memcached p 116 For sample NET code to use the client see Using the ElastiCache Cluster Client for NET p 120 Topics Installing NET p 210 Download the ElastiCache NET Cluster Client for ElastiCache p 210 e Install AWS Assemblies with NuGet p 211 Installing NET You must have NET 3 5 or later installed to use the AWS NET SDK for ElastiCache If you don t have NET 3 5 or later you can download and install the latest version from http www microsoft com net D
40. Go Se g A Replica f b Sa Multi AZ if Everything Fails If everything fails ElastiCache recreates and provisions all clusters in the replication group as described following In this scenario all the data in the cache is lost due to the failure of every node in the replication group Such occurrences are rare 1 ElastiCache takes the failed primary cluster and replicas offline 2 ElastiCache creates and provisions a replacement primary cluster and replacement replicas API Version 2015 02 02 34 Amazon ElastiCache User Guide Enabling Redis Multi AZ Reads and writes to the primary can resume only after the new primary cluster is created and provisioned This takes significantly longer than promoting a replica to primary If possible the replacements are created in the Availability Zones of the failed nodes so that the distribution of clusters is maintained To read from or write to the new primary you do not need to update your primary endpoint To read from a replacement replica you must update the endpoint and wait for it to finish provisioning The following diagram illustrates this scenario a es Ps se A O AZ a D ip Failed 4 New Primary t nary 7 s2 b N 7 azec N ee ea e wise Gapliyy Ca Ea o 7 Enabling Redis Multi AZ You can enable Redis Multi AZ when you create a Redis replication group using the ElastiCache console CLI or API Enabling Redis Multi AZ Using the ElastiCache
41. Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Clusters 3 Inthe Cache Clusters list locate the Nodes column and click the number of nodes link of the cluster you want to modify Filter All Cache Clusters Q x 4 Clusters Cache Cluster Engine Nodes Node Type codes Status The detail panel appears 4 Click the Nodes tab A list of nodes for the cluster appears 5 Click the Add Node button at the top of the list The Add Node dialog box appears API Version 2015 02 02 96 Amazon ElastiCache User Guide Adding or Removing Nodes 6 7 8 In the Number of Nodes to Add box type the number of nodes you want to add From the list select No Preference Spread Nodes Across Zones or Specify Zones No Preference If your existing nodes are all in the same Availability Zone ElastiCache creates all new nodes in the same Availability Zone If your existing nodes are spread across different Availability Zones ElastiCache spreads the new nodes across different Availability Zones Spread Nodes Across Zones ElastiCache selects the Availability Zones in which to create your new nodes Specify Zones You specify how to distribute the new nodes across Availability Zones If you select Specify Zones the wizard expands with a list of usable Availability Zones Type the number of new nodes to create in that zone T
42. Resource p 66 e Listing the Tags for an ElastiCache Resource p 68 Modifying Tags on Your ElastiCache Resource p 70 Removing Tags from Your ElastiCache Resource p 71 Copying Tags to Your ElastiCache Resources p 73 Adding Tags to Your ElastiCache Resource You can add tags to an ElastiCache resource by using the ElastiCache management console AWS CLI or ElastiCache API Topics ElastiCache Management Console p 66 e AWS CLI p 67 ElastiCache API p 68 ElastiCache Management Console You can use the ElastiCache management console to add tags to an ElastiCache resource A resource can have a maximum of 10 tags To add a tag to an ElastiCache resource using the ElastiCache management console 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache Depending what ElastiCache resource you want to add a tag to click Clusters or Snapshots 3 Select the ElastiCache resource you want to add a tag to After you select the resource you can see the tag names and values currently on this resource at the bottom of the details area 4 Click Manage Tags at the top of the screen 5 To add a tag to this resource do the following in the Manage Tags dialog box 1 Inthe Key column type a key name in the text box that displays Add key API Version 2015 02 02 66 Amazon ElastiCache User Guide AWS CLI 6 2 To add value to
43. Select the ElastiCache resource for which you want to see the tag list The tags currently on this resource are listed at the bottom of the details area e F memcached 1 node cache r3large us east 1d Cache Cluster ID Configuration Endpoint Creatic Engine Cache Node Type Number of Cache Nodes memcached cache r3 large 1 Nodes Pending Deletion Cache Parameter Group Security Group s Maintenance Window default memcached 4 in sync default active at04 00 sat05 00 Engine Availability Number of Nodes Pending C Replicatior Cache Subne Notificati Backup Retention Backup Window N A Tags AWS CLI You can use the AWS CLI to list tags on an existing ElastiCache resource by using the list tags for resource command The following code uses the ElastiCache AWS CLI to list the tags on the resource myCluster in the us west 2 region The resource name parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt PROMPT gt aws elasticache list tags for resource resource name arn aws elastic ache us west 2 0123456789 cluster myCluster ElastiCache API You can use the ElastiCache API to list tags on an existing resource by using the ListfagsForResource action The following code uses the ElastiCache API to list the tags on the resource myCluster in the us west 2 region
44. The status of the cluster will change to deleting While this cluster is deleting you can delete other clusters by repeating steps 1 through 4 For information on creating Redis replication groups see Creating a Redis Multiple Cluster Replication Group p 127 Step 3 Authorize Access This section assumes that you are familiar with launching and connecting to Amazon EC2 instances For more information go to the Amazon EC2 Getting Started Guide All ElastiCache clusters can only be accessed from an Amazon EC2 instance A cluster and its related Amazon EC2 instance must be in the same Amazon Virtual Private Cloud VPC If you must access an ElastiCache cluster from somewhere other than an Amazon EC2 instance in the same VPC as a workaround you can set up one or more Amazon EC2 hosts inside the cache s VPC to act as a proxy for the outside world Setting up a host adds an extra network hop or extra Secure Sockets Layer SSL overhead and cost or both However those costs are small for many use cases You must grant the proxy Amazon EC2 instance access to your cluster API Version 2015 02 02 15 Amazon ElastiCache User Guide You Launched Your Cluster into EC2 VPC By default network access to your cluster is limited to the user account that was used to launch it Before you can connect to a cluster from an Amazon EC2 instance you must authorize the Amazon EC2 instance to access the cluster The steps required depend upon whether
45. This command should produce output similar to the following the following example has been truncated R R CACHEPARAMETE Type Is CACHEPARAMETE false CACHEPARAMETE fals CACHEPARAMETE true CACHEPARAMETE true CACHEPARAMETE tru CACHEPARAMETE true CACHEPARAMETE false Parameter Name odifiable Minimum Version backlog_queue_limit 1024 L435 binding_protocol auto 1 4 5 cas_disabled 0 Irs chunk_size 48 1 4 5 chunk_size_growth_factor 1 25 1 4 5 error_on_memory_exhausted 0 dh PES large_memory_pages 0 1 4 5 sample truncated Parameter Value Source Data system integer system string system boolean system integer system float system boolean system boolean API Call DescribeCacheParameters with the following parameter e CacheParameterGroupName myCacheParameterGroup API Version 2015 02 02 159 Amazon ElastiCache User Guide Viewing Parameter Values for a Cache Parameter Group Example https elasticache us west 2 amazonaws com Action DescribeCacheParameters amp CacheParameterGroupName mycacheparametergroup amp MaxRecords 100 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141
46. a Cache Cluster miesni ennd eect eee a eaa TE aR Ta E E naa NFEE Sani 114 Managing Nod Ssis seneso anii ne a e a ond A Aa EVE SETE 116 Node Auto Discovery Memcached cceceeeeeee nee e teeta ee eee een eea eed eeaeeaeeaeeaeeaeeaeeaeeaeeaeed 116 Actions You Can Take When a Node is Scheduled for Replacement eeeeeeeeeeeeeeee ees 125 Managing Replication Groups ceceeeeeeeee eee ee neta tenet nee ne eens se eneeaeeseeseeseeseeseeaeeseeseeeeeeeeeeeaes 127 Creating a Redis Replication Group ccceceeeeeee nett eee teeta eee eaten eee ee deta een eea een eeaeeneeas 127 Adding a Read Replica To a Replication Group cceeeeeeeeeeeeeeeaeeeeeaeeeeeaeeeeeaeeaeeaeeneed 133 Promoting a Read Replica to the Primary Role ccceeeeeeneeeeee eee eeneeeeeaeeeeeaeeneeaeeneeaes 134 Modifying an Existing Redis Replication Group eeceeeeeeneeeeeeeeeeeaeeeeeaeeneeaeeneeaeeneeaes 135 Deleting a Read Replica 2 2 2 0 ccc ccce cece cece cence eee eee eian ae aei esac ese r anA 136 Deleting a Replication Group 0 ccccceeceee eee eee eee eect cee c eee e ce ece eee eee ese esas esas esaeseeeeesees 137 Managing Backup and Restore Redis ceeeeee eect eee reer ee rere etre eter etnies 139 Enabling Automatic Snapshots on a New Cluster cceeeeeeeeeeeceeeeeeeeeeeseeeeeeeeeeeeeeeeenes 139 Enabling Automatic Snapshots for an Existing Cluster cceee
47. a ee eel eee eae 73 Copying Tags to Your ElastiCache Resources ceeeee eee ee eee ee eee e ees eee ee aeeeeeaeeseeaeeseeaeeeeeaeeaeed 73 CloudWatch Metrics with ElastiCache cc entre etre ee ee need 74 Dimensions for ElastiCache Metrics ccceceeee eee e cette eee eee ee eee teeta e eee ated e ated eee ee deen eeaeeanenes 74 Choosing Metric Statistics and Periods ceeeceee eee eee eee e ee eee ee eeee eee eceeeeeeeeseeseeeeeseeeeeeeeeeeaeees 75 Host Level Metrics ics nerder nees eden ded sacencatoedba ne Fuse atigs Sea ted sabes eeaecnhe eet eataee teamed Seaeen ge tence ds 75 Metrics for Memcached 2i 0 4tccedine see Sinden a ited en ea E V A A A E aa 75 Metriessfor Redis semeen reinaan re Er Went A EE S E tee des wae geee een tes tea 78 Which Metrics Should Monitor 2 0 2 0 ccceeeee eee ee eee cece ee eee ee eee ee ees eee ese eseeaeeseeaeeseeaeeeeeaeeaeeaeees 79 Setting Up the ElastiCache Command Line Interface cceceeeeee eee nee eee eee eee ee eee a eee een eee een eee eeaeeaeeaes 81 Prerequisite Sinsice ronisin a nando lei a ede Are eee ee eee t eect 81 The Java Runtime Environment 0 cceceee cece ee eee ee eee een ea nec ea tease eceeaeeaeeseeaeeeeeaeeaeeaes 81 Getting the Command Line Tools cccceceseeeeceeceece eee eee ese ece ese eee ese esa esas eseeseeseseeseeeeeseeeeees 82 Setting Up the LOOMS cecxececenbesde eca s anc eaa Sanne ne ge
48. amazonaws com Action DescribeCacheSecurityGroups amp CacheParameterGroupName mycachesecuritygroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Authorizing Network Access to an Amazon EC2 Security Group If you want to access your cache cluster from an Amazon EC2 instance you must grant access to the Amazon EC2 security group that the EC2 instance belongs to The following procedures show you how to grant access to an Amazon EC2 Security Group Important Authorizing an Amazon EC2 security group only grants access to your cache clusters from the EC2 instances belonging to the Amazon EC2 security group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console amazonaws cn elasticache 2 Inthe left navigation pane select Cache Security Groups 3 Inthe Cache Security Groups list select the check box next to the cache security group that you want to grant access to 4 Atthe bottom of the window in the EC2 Security Group Name list select your Amazon EC2 security group 5 Click the Add button Note It takes approximately one minute for changes to access p
49. cluster One or more EC2 security groups have been revoked from any of the cache security groups associated with the cache cluster ElastiCache has detected that the host running a cache node is degraded or unreachable and has completed replacing the cache node Note The DNS entry for the replaced cache node is not changed In most instances you do not need to refresh the server list for your clients when this event occurs However some cache client libraries may stop us ing the cache node even after ElastiCache has re placed the cache node in this case the application should refresh the server list when this event oc curs One or more cache nodes has been rebooted An operation could not be completed because the AWS account has been suspended The deletion of a cache cluster and all associated cache nodes has completed A node in your cluster that was scheduled for re placement is no longer scheduled for replacement A node in your cluster previously scheduled for re placement has been rescheduled for replacement during the new window described in the notification For information on what actions you can take go to Actions You Can Take When a Node is Sched uled for Replacement p 125 API Version 2015 02 02 194 Amazon ElastiCache User Guide Event Name Description ElastiCache NodeReplacementScheduled A node in your cluster is scheduled for replacement during the window described in the not
50. cluster to delete click the box to the left of the cluster s name When selected the box will have a colored center API Version 2015 02 02 114 Amazon ElastiCache User Guide Deleting a Cache Cluster You can only delete one cluster at a time from the ElastiCache console Selecting multiple clusters disables the Delete button 4 Click the Delete button The status of the cluster will change to deleting While this cluster is deleting you can delete other clusters by repeating steps 1 through 4 CLI To delete a cluster use the command elasticache delete cache cluster PROMPT gt elasticache delete cache cluster my cache cluster forc This command will produce output similar to the following CACHECLUSTER my cache cluster https console aws amazon com elastic ache home client download my cache cluster q68zge cfg usel cache amazonaws com 11211 2013 07 22T20 29 54 663Z2 cache ml larg memcached deleting 3 us west 2a 1 4 14 CACHESECURITYGROUP default active CACHEPARAMETERGROUP default memcached1l 4 in sync API To delete a cluster call the DeleteCacheCluster action with the following parameter CacheClusterId my cache cluster This call returns output similar to the following Example https elasticache us west 2 amazonaws com Action DeleteCacheCluster amp CacheClusterId my cache cluster amp SignatureVersion 4 amp
51. command The following example creates the Multi AZ enabled replication group my rg with 3 cache clusters the primary cluster my rg001 and two replicas my rg002 and my rg003 https elasticache us west 2 amazonaws com Action CreateReplicationGroup AutomaticFailover true amp CacheNodeType cache m3 large amp Engine redis API Version 2015 02 02 37 Amazon ElastiCache User Guide Backup and Restore for Redis Clusters amp NumCacheNodes 3 amp ReplicationGroupId my rg amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T1923172 amp X Amz Credential lt credential gt When you create the clusters and replication group as shown in this example the names of the clusters are created by adding a three digit sequential number starting at 001 to the end of the replication group s names For more information see http docs amazonaws cn AmazonElastiCache latest AP IReference API _CreateCacheCluster html and http docs amazonaws cn AmazonElastiCache latest APIReference API_CreateReplicationGroup html Using the ElastiCache API to Enable Redis Multi AZ for an Existing Replication Group The following code example uses the ElastiCache API to enable Multi AZ for the replication group myReplGroup https elasticache us west 2 amazonaws com Action ModifyReplicationGroup amp AutoFailover true amp ReplicationGroupId myRep1
52. esa een eea een eea een eeaes 4 Cache Replication Groups ccceceeenee eee ee erence a een eee een eea een esate nese een eea een ai i aaaea E 4 SCU mois fs ena he snedhe a a genta aan on a a E E E 5 Supported Operations cece 5 Cache Cluster Operations arepe E e ra EO E T EE aE E E EE EEES 5 Cache Node Parameter Operations cccceeeee eee eeeeeeee een ee eee eee eaeeeeeaeeeeeaeeeeeaeeeeeaeeaeed 5 Cache Replication Group Operations Redis Only ececeeeeee eee nee eee eee ee neta een eta een eea een eee eed 6 Accessing Amazon ElastiCache ccceceeeneeeeee eee eee e ee eee eee eee eceeseeseeseeseeseeeeeeeeseeseeeeeseeeeeaeeeees 6 R gions and EROPOINIS rerainane ea came whshagie cand E E TE EE E E 6 Supported REGIONS sisane eaa a ae a E EE rE a ae A cee ARE aE Sob pees A eA a a AEA 6 Getting Started with Amazon ElastiCache ccccccccceeceeeeceeeec cence eeeeeeceeeeceeeeeeeeeeeseeeeseeeeseeeeeeeneaeees 8 step 1 Before You Begin seinor iano a tabs pada Ea E EA E noe A 8 Step 2 kaunch a Cluster issesesaee emip eee nna EE Ear EE E E GEE EEEa S a ERD 8 Step 2 Launch a Memcached Cluster cccceceececeeeeeeeeeeeee sence eceeeeeeeeeeeeeeeeeeeeeeeeeeeneees 9 Step 2 Launch a Redis Cluster cccececcec cece eee eceeeeceeeeeeeeeaeeeeeeseeeeseeeeeeeeeeeeeseseeneeees 12 Step 3 Authorize ACCESS a r a e Ci itd ee a ook t hg 15 You Launched Your Cluster into EC2 VP
53. group is named MyGroup then the names of the secondaries would be MyGroup 002 MyGroup 003 MyGroup 004 MyGroup 005 MyGroup 006 S3 Location of Redis RDB file Amazon S3 location of the rdb file used to seed this cluster If this is left blank this cluster will not be seeded upon creation For more information on snapshots and seeding a Redis cluster see Backup and Restore for Redis Clusters p 38 and Migrating Your Redis Cluster to ElastiCache p 151 3 Click Next Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details To configure your replication group s advanced settings 1 Inthe Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this replication group and it s clusters associated with e To launch this replication group and it s clusters in EC2 VPC recommended select a VPC subnet group To launch this replication group outside a VPC click Not in VPC The replication group and it s clusters will be launched in EC2 Classic Availability Zone s From the drop down lists select the availability zone for the primary and each of the secondary clusters or accept the ElastiCache assigned zones Cache Security Group s or VPC Security Group s Select the security group s for this replication group API Version
54. high utilization period If you do not specify a backup window ElastiCache will assign one automatically Snapshot retention limit The number of days the snapshot will be retained in Amazon S3 For example if you set the retention limit to 5 then a snapshot taken today would be retained for 5 days When the retention limit expires the snapshot is automatically deleted The maximum snapshot retention limit is 35 days The minimum is 0 meaning that automatic snapshots are disabled for the cluster For more information see Managing Backup and Restore Redis p 139 Manual Snapshots In addition to automatic snapshots you can create a manual snapshot at any time For example if an automatic snapshot is nearing its snapshot retention limit you can make a copy of that snapshot and keep the copy until you decide to delete it Manual snapshots are also useful for archiving purposes For example suppose that you ve developed a set of baseline data for testing purposes you can create a manual snapshot of the data and restore it whenever you want After you test an application that modifies the data you can reset the data by creating API Version 2015 02 02 39 Amazon ElastiCache User Guide Performance Impact of Snapshots a new cluster and restoring from your baseline snapshot When the cluster is ready you can test your applications against the baseline data again and repeat this process as often as needed You can creat
55. in the availability of your cluster running Memcached The failure of a single cache node can have an impact on the availability of your application and the load on your back end database while ElastiCache provisions a replacement for the failed cache node You can reduce this potential availability impact by spreading your memory and compute capacity over a larger number of cache nodes each with smaller capacity rather than a fewer number of high capacity nodes In a scenario where you want to have 40 GB of cache memory you can set it up in one of the following ways e Use 13 cache t2 medium cache nodes with 3 22 GB of memory each 41 86 GB e Use 7 cache m3 large cache nodes with 6 05 GB of memory each 42 35 GB e Use 3 cache r3 large cache nodes with 13 5GB of memory each 40 5 GB These options each provide you with similar memory capacity but different computational capacity for your cluster Note For clusters running Memcached some of the available memory on each cache node is used for connection overhead For more information see Understanding and Tuning Memcached Connection Overhead p 46 If you re unsure about how much capacity you need we recommend starting with one cache m3 medium cache node type and monitoring the memory usage CPU utilization and cache hit rate with the ElastiCache metrics that are published to CloudWatch If your cluster does not have the desired hit rate you can easily add more nodes thereby incre
56. instance 1 Connect to your existing Redis instance 2 Runeither the BGSAVE or SAVE command to create the snapshot The snapshot will be written locally to a Redis database file rdb BGSAVE is asynchronous and does not block other clients while processing For more information go to http redis io commands bgsave SAVE is synchronous and blocks other processes until finished For more information go to http redis io commands save For additional information on creating a snapshot see htip redis io topics persistence Upload your Snapshot to Amazon 3 Once you have created the snapshot file you will need to upload it into an Amazon S3 bucket For more information on this task see the Amazon Simple Storage Service Getting Started Guide The name of your Amazon S3 bucket must be DNS compliant otherwise ElastiCache will not be able to access your snapshot file The rules for DNS compliance are the following Names must be at least 3 and no more than 63 characters long e Names must be a series of one or more labels separated by a period where each label e Must start with a lowercase letter or a number e Must end with a lowercase letter or a number e Must contain only lowercase letters numbers and dashes Names cannot be formatted as an IP address e g 192 0 2 0 For additional information go to Bucket Restrictions and Limitations in the Amazon Simple Storage Service Developer Guide Important
57. linebreaks added for clarity https elasticache us west 2 amazonaws com Action DescribeCacheClusters amp CacheClusterIdentifier myCacheCluster amp SignatureMet hod HmacSHA256 amp SignatureVersion 4 amp Version 2014 12 01 For the preceding query string you would calculate the HMAC signature over the following string GET n elasticache amazonaws com n Action DescribeCacheClusters amp CacheClusterIdentifier myCacheCluster amp SignatureMethod HmacSHA256 amp SignatureVersion 4 amp Version 2014 12 01 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Credent ial AKIADQKE4 SARGYLE 2F20140523 2Fus west 2 2Felasticache 2Faws4_re quest amp X Amz Date 20141201T223649Z amp X Amz SignedHeaders content type 3Bhost 3Buser agent 3Bx amz content sha256 3Bx amz date content type host elasticache us west 2 amazonaws com user agent CacheServicesAPICommand_Client x amz content sha256 API Version 2015 02 02 190 Amazon ElastiCache User Guide Available Libraries x amz date The result is the following signed request https elasticache us west 2 amazonaws com Action DescribeCacheClusters amp CacheClusterIdentifier myCacheCluster amp SignatureMet hod HmacSHA256 amp SignatureVersion 4 amp Version 2014 12 01 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Credential AKIADQKE4SARGYLE
58. lt Source gt lt IsModifiable gt false lt IsModifiable gt lt Description gt The backlog queue limit lt Description gt lt lt lt AllowedValues gt 1 10000 lt AllowedValues gt ParameterName gt backlog_queue_limit lt ParameterName gt inimumEngineVersion gt 1 4 5 lt MinimumEngineVersion gt lt Parameter gt lt Parameter gt lt ParameterValue gt auto lt ParameterValue gt DataType gt string lt DataType gt Source gt system lt Source gt IsModifiable gt false lt IsModifiable gt Description gt Binding protocol lt Description gt AllowedValues gt auto binary ascii lt AllowedValues gt ParameterName gt binding_protocol lt ParameterName gt lt MinimumEngineVersion gt 1 4 5 lt MinimumEngineVersion gt lt Parameter gt lt be EA lt lt lt sse output omitted lt Parameters gt lt DescribeCacheParametersResult gt lt ResponseMetadata gt lt RequestId gt 6qd355589 af49 11e0 97f9 279771c4477e lt RequestId gt lt ResponseMetadata gt lt DescribeCacheParametersResponse gt API Version 2015 02 02 161 Amazon ElastiCache User Guide Modifying a Cache Parameter Group Modifying a Cache Parameter Group You can modify parameters in a cache parameter group These parameters are applied to cache clusters associated with the cache parameter group when the cache cluster is rebooted Note The default memcached1 4 parameter group fam
59. node the primary endpoint always points to the primary node for the replication group For read only activity applications can connect to any node in the replication group However for write activity we recommend that your applications connect to the primary endpoint instead of connecting directly to the primary node Creating a Replication Group For detailed guidance on creating a replication group see Creating a Redis Replication Group p 127 For detailed procedures on each step see Managing Replication Groups p 127 API Version 2015 02 02 31 Amazon ElastiCache User Guide Adding a Redis Cache Clusier to a Replication Group Adding a Redis Cache Cluster to a Replication Group For detailed guidance on adding a read replica to a replication group see Adding a Read Replica To a Replication Group p 133 Multi AZ with Redis Replication Groups An ElastiCache for Redis replication group consists of a primary cluster and from one to five read replicas When Multi AZ is enabled for a replication group and a primary node fails ElastiCache automatically detects the failure selects a read replica and promotes it to primary without any manual intervention This functionality means you can resume writing to the primary node as soon as promotion is complete generally in 3 to 4 minutes ElastiCache replication groups with Multi AZ enabled significantly reduce the time span during which you cannot write to the read write pri
60. of clusters is maintained To read from the replacement replica you must update to its endpoint and wait for it to finish provisioning The following diagram illustrates this scenario Sou aza Failed m aie i Repli p my y genlea li a aa i AzZ b AZ c Zb Az c Replica Replica Promoted Replica NS P W P Replica Sui 4 Gay a Multi AZ if Everything Fails Except One Replica If everything fails except one replica ElastiCache performs the following process 1 ElastiCache takes the failed primary cluster and failed replicas offline 2 ElastiCache promotes a replica that did not fail to the primary role Write operations can resume as soon as the promotion process is complete typically 3 to 4 minutes You don t need to change the endpoint for write operations because ElastiCache propagates the DNS address of the promoted replica 3 ElastiCache creates and provisions replacement replicas If possible the replacement replicas are created in the Availability Zones of the failed clusters so that the distribution of clusters is maintained To read from the replacement replicas you must update endpoints and wait for the replicas to finish provisioning The following diagram illustrates this scenario az a aS AZ a P Failed New i y y Nee am yn LO aa cn es Replica Primary XN ee A N
61. or select from an existing one below Learn more about Amazon EC2 security groups Assign a security group Create a new security group Select an existing security group Security Group ID Name Description g 1a3d2178 default defaut VPC security group 4 sg f13d2193 my vpc security group Testing Click the name of your Amazon VPC security group and then click Review and Launch 7 On the Review Instance and Launch page click Launch A new window appears Select an existing key pair or create a new key pair In this window specify a key pair that you want to use with this instance Note For information about managing key pairs go to the Amazon EC2 Getting Started Guide When you are ready to launch your Amazon EC2 instance click Launch Instances You can now assign an Elastic IP address to the Amazon EC2 instance that you just created You will need to use this IP address to connect to the Amazon EC2 instance To assign an Elastic IP address Open the Amazon VPC console at https console www amazonaws cn vpc In the navigation list click Elastic IPs Click Allocate New Address In the Allocate New Address dialog box in the EIP used in box click VPC and then click Yes Allocate Select the Elastic IP address that you just allocated from the list and click Associate Address 6 Inthe Associate Address dialog box in the Instance box click the ID of the Amazon EC2 instance that you launched and then click Yes Asso
62. output similar to the following CACHECLUSTER my replica l https console aws amazon com elasticache home cli ent download cache ml small redis creating 1 2 6 13 my repgroup CACHESECURITYGROUP default active CACHEPARAMETERGROUP default redis2 6 in sync API To add a read replica to an existing replication group use the CreateCacheCluster action with the Replicat ionGroupId parameter The following example creates a new cache cluster named my replica 1 and adds it to the my repgroup replication group API Version 2015 02 02 133 Amazon ElastiCache User Guide Promoting a Read Replica to the Primary Role Example https elasticache us west 2 amazonaws com Action CreateCacheCluster amp CacheClusterId my replica 1 amp ReplicationGroupId my repgroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 201412017T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Promoting a Read Replica to the Primary Role In a replication group you can designate any read replica as the new primary cache cluster The existing primary cluster becomes a read replica and the read replica that you designate is promoted to the pr
63. parameter Required parameter for DeleteSnapshot e SnapshotName The following example deletes the snapshot my manual snapshot API Version 2015 02 02 153 Amazon ElastiCache User Guide Deleting Snapshots Example https elasticache us west 2 amazonaws com Action DeleteSnapshot amp SnapshotName my manual snapshot amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 201410217T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 154 Amazon ElastiCache User Guide Managing Cache Parameter Groups Managing Cache Parameter Groups A cache parameter group is initially created with the default parameters for the cache engine used by the cache cluster To provide custom values for any of the parameters you must modify the group after creating it In this example you create list modify and examine cache parameter groups Caution Improperly setting parameters in a cache parameter group can have unintended adverse effects including degraded performance and system instability Always exercise caution when you are modifying cache parameters or your cache parameter group Note Some cache engine parameters are constrained or disabled in the
64. ready to create your new cluster To do this follow the instructions at Creating a Cluster p 89 Be sure to select Redis as your cluster engine How you tell ElastiCache where to find the Redis snapshot that you uploaded to Amazon S3 depends on the method you use to create the cluster AWS Management Console If you use the AWS Management Console in the Configuration section of the Specifiy Cluster Details screen type the S3 path for the snapshot you copied to your Amazon S3 bucket in the previous section in the S3 Location of Redis RDB file text box The S3 path will look something like myS3bucket myFolder mySnapshotFilename rdb where myS3bucket is the name of the Amazon S3 bucket you have access to myFolder is the folder you saved the rdb file in and mySnapshotFilename is the name of the rdb backup snapshot file CLI If you use the create cache cluster command use the snapshot arns parameter to specify a fully qualified ARN such as arn aws s3 my bucket my folder my snapshot filename The ARN must resolve to the snapshot file that you stored in Amazon Amazon S3 API If you use the CreateCacheCluster API use the SnapshotArns parameter to specify a fully qualified ARN such as arn aws s3 my bucket my folder my snapshot filename The ARN must resolve to the snapshot file that you stored in Amazon Amazon S3 During the process of creating your cluster the data in your Redis snapshot will be written to the cl
65. snapshots in the current AWS account PROMPT gt elasticache describe snapshots To display a list of snapshots use the DescribeSnapshots action The following example displays a list of all of the snapshots in the current AWS account Example https elasticache us west 2 amazonaws com Action DescribeSnapshots amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Copying a Snapshot You can make a copy of any snapshot whether it was created automatically or manually The following procedures show you how to copy a snapshot API Version 2015 02 02 148 Amazon ElastiCache User Guide Restoring a Snapshot to a New Cluster AWS Management Console To copy a snapshot using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Snapshots In the list of snapshots select the one that you want to copy and then click Copy Snapshot 4 Inthe New Cache Snapshot Identifier text box type a name for your new snapshot and then click Copy w CLI To copy a
66. specifies myPrimaryCluster as the primary cluster https elasticache us west 2 amazonaws com Action CreateReplicationGroup amp AutomaticFailover true amp Description My replication group amp PrimaryClusterlId myPrimaryCluster amp ReplicationGroupId myRep1lGroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T1923172Z amp X Amz Credential lt credential gt Add a replica Redis cache cluster to the replication group as shown in the following example that creates myReplicaCluster00 as a read replica in the myRep1Group replication group You can perform this step up to five times changing only the name of the cluster https elasticache us west 2 amazonaws com Action CreateCacheCluster amp CacheClusterId myReplicaCluster00 amp ReplicationGroupId myRep1lGroup amp SignatureMethod HmacSHA256 amp SignatureVersion 4 amp Version 2014 12 01 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Credential your access key id 20140721 us west 2 elastic ache aws4_request amp X Amz Date 20141201T1706512 amp X Amz SignedHeaders content type host user agent x amz content sha256 x amz date amp X Amz Signature signature value If you don t have an active Redis cache cluster to use as the primary cluster you can create the replication group and its associated cache clusters with a single
67. that cache subnet group to select a subnet and IP addresses within that subnet to associate with your cache nodes For more information about cache subnet group usage in an Amazon VPC environment see Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 and Step 3 Authorize Access p 15 Security Groups Note Security groups are only applicable to clusters that are not running in an Amazon Virtual Private Cloud environment VPC If you are running your ElastiCache nodes in an Amazon VPC you control access to your cache clusters with Amazon VPC security groups which are different from ElastiCache security groups For more information on using ElastiCache in an Amazon VPC see ElastiCache and Amazon Virtual Private Cloud p 60 and Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 ElastiCache allows you to control access to your clusters using security groups A security group acts like a firewall controlling network access to your cluster By default network access is turned off to your clusters If you want your applications to access your cluster you must explicitly enable access from hosts in specific Amazon EC2 security groups Once ingress rules are configured the same rules apply to all clusters associated with that security group To allow network access to your cluster create a security group and use the AuthorizeCacheSecurityGroupiIngress API or CLI command to authorize the desired Amazon EC2
68. the AWS Command Line Interface Topics e Prerequisites p 81 Getting the Command Line Tools p 82 Setting Up the Tools p 83 e Providing Credentials for the Tools p 84 Environmental Variables p 84 Prerequisites This document assumes that you can work in a Linux UNIX or Windows environment The Amazon ElastiCache command line tools also work on Mac OS X which is a UNIX based environment however no specific Mac OS X instructions are included in this guide As a convention all command line text is prefixed with a generic PROMPT gt command line prompt The actual command line prompt on your machine is likely to be different We also use to indicate a Linux UNIX specific command andc gt fora Windows specific command The example output resulting from the command is shown immediately thereafter without any prefix The Java Runtime Environment The command line tools used in this guide require Java version 5 or later to run Either a JRE or JDK installation is acceptable To view and download JREs for a range of platforms including Linux UNIX and Windows go to Java SE Downloads API Version 2015 02 02 81 Amazon ElastiCache User Guide Getting the Command Line Tools Setting the Java Home Variable The command line tools depend on an environment variable JAVA_HOME to locate the Java Runtime This environment variable should be set to the full path of the directory that contains a subdirectory named b
69. the cache nodes and begin using the cache While your cache cluster is running you can use the ModifyCacheCluster operation to add or remove cache nodes modify the cache engine parameters or change the security settings for all nodes in the cluster If you decide that you no longer need the cache cluster you can use the DeleteCacheCluster operation to shut down all of the cache nodes and release all of the other resources associated with the cluster For more information see Managing Clusters p 89 For information on migrating your existing Redis cache clusters to ElastiCache see Migrating Your Redis Cluster to ElastiCache p 151 Cache Node Parameter Operations The supported cache engines in ElastiCache provide several runtime parameters which you can use to fine tune your cache cluster s performance The CreateCacheParameterGroup operation lets you create a template set of parameters that are compatible with the cache engine that you are using Memcached or Redis You can the use the ModifyCacheCluster operation to apply the parameters to all of the cache nodes you can do so immediately or wait for the next system maintenance window for your cache cluster For more information see Managing Cache Parameter Groups p 155 API Version 2015 02 02 5 Amazon ElastiCache User Guide Cache Replication Group Operations Redis only Cache Replication Group Operations Redis only If you have a single node cache
70. the term The following table summarizes the differences between the reserved cache nodes offering types Reserved Cache Node Offerings Offering Up Front Cost Usage Fee Advantage Heavy Utilization Highest Lowest hourly fee Ap Lowest overall cost if plied to the whole term whether or not you re using the reserved you plan to use your re served cache nodes more than 79 percent of cache node a 3 year term Medium Utilization Average Hourly usage fee Suitable for elastic charged for each hour workloads or when you you use the cache node expect moderate usage more than 40 percent of a 3 year term Light Utilization Lowest Hourly usage fee Highest overall cost if charged Highest fees of all the offering types but fees apply only when you re using the re served cache node you plan to run all of the time however lowest overall cost if you anticip ate you will use your re served cache nodes in frequently more than about 15 percent of a 3 year term For more information on working with reserved cache nodes go to Managing Reserved Nodes p 106 Replication Groups and Read Replicas Redis By default cache clusters are stand alone entities without any redundant data protection services However if your cache cluster is running on Redis your cache cluster is a single node A replication group is a collection of nodes with one primary read write cluster and up to five secondary read only clusters w
71. the values of any parameters in the default parameter group however you can always create a custom parameter group and assign it to your cluster at any time Memcached 1 4 14 Added Parameters For Memcached 1 4 14 the following additional parameters are supported Name Default Type Modifi Description able config_max 16 integer No The maximum number of ElastiC ache configuration entries config_size_max 65536 integer No The maximum size of the configur ation entries in bytes hashpower_init 16 integer No The initial size of the ElastiCache hash table expressed in powers of two The default is 2 16 or 65536 keys API Version 2015 02 02 44 Amazon ElastiCache User Guide Parameters for Memcached Name Default Type Modifi able maxconns_fast 0 false Boolean Yes slab_automove 0 integer Yes slab_reassign 0 false Boolean Yes Memcached 1 4 5 Parameters Description Changes the way in which new connections requests are handled when the maximum connection limit is reached If this parameter is set to 0 zero new connections are added to the backlog queue and will wait until other connec tions are closed If the parameter is set to 1 ElastiCache sends an error to the client and immediately closes the connection Adjust the slab automove al gorithm If this parameter is set to 0 zero the automove algorithm is disabled If it is set to 1 ElastiC ache takes a slow conservative approa
72. true ElastiCache will try to use large memory pages lock_down_paged_memory 0 false Boolean No If 1 true ElastiCache will lock down all paged memory max_item_size 1048576 integer Yes The size in bytes of the largest item that can be stored in the cache max_simultaneous_ connections 65000 integer No The maximum number of simultan eous connections maximize_core_file_limit 0 false Boolean No If 1 true ElastiCache will maxim ize the core file limit memcached_connections_over 100 integer Yes The amount of memory to be re head served for memcached connec tions and other miscellaneous overhead For information about this parameter see Understand ing and Tuning Memcached Con nection Overhead p 46 requests_per_event 20 integer No The maximum number of requests per event for a given connection This limit is required to prevent resource starvation Understanding and Tuning Memcached Connection Overhead On each cache node the memory made available for storing cache items is the total available memory on that cache node which is stored in the max_cache_memory parameter minus the memory used for connections and other overhead which is stored in the memcached_connect ions_overhead parameter For example a node of type cache m1 small has amax_cache_memory of 1300MB With the default memcached_connections_overhead value of 100MB the Memcached process will have 1200MB available to store cache ite
73. when a node is scheduled for replacement go to ElastiCache s Event Notifications and Amazon SNS p 193 Date Changed June 11 2015 ElastiCache added support for Redis version 2 8 19 and March 11 2015 Redis improvements since version 2 8 6 This support in cludes support for The HyperLogLog data structure with the Redis com mands PFADD PFCOUNT and PFMERGE F e Lexicographic range queries with the n ZRANG EBYL EX ZL EXCOUNT and ZRE BYL ew commands RANGE EX Introduced a number of bug fixes namely preventing a primary node from sending stale data to replica nodes by failing the master SYNC when a background save bgsave child process terminates unexpectedly For more information on HyperLogLog go to Redis new data structure the HyperLogLog For more information on PFADD PFCOUNT and PFMERGE go to the Redis Docu mentation and click HyperLogLog API Version 2015 02 02 212 Amazon ElastiCache User Guide Change Support for cost al location tags Support for AWS GovCloud US re gion Description ElastiCache added support for cost allocation tags Date Changed February 9 2015 For more information see Using Cost Allocation Tags in ElastiCache p 65 ElastiCache added support for the AWS GovCloud US January 29 2015 us gov west 1 region Support for EU Frankfurt region Multi AZ wi
74. whenever a node is added or removed from a cluster the number of keys that must be moved is roughly 1 n where nis the new number of nodes Scaling from 1 to 2 nodes results in 1 2 50 percent of the keys being moved the worst case Scaling from 9 to 10 nodes results in 1 10 10 percent of the keys being moved As the user you control which hashing algorithm is used for multi node clusters We recommend that you configure your clients to use consistent hashing Fortunately there are many Memcached client libraries in most popular languages that implement consistent hashing Check the documentation for the library you are using to see if it supports consistent hashing and how to implement it If you are working in Java PHP or NET we recommend you use one of the Amazon ElastiCache client libraries Consistent Hashing Using Java The ElastiCache Memcached Java client is based on the open source spymemcached Java client which has consistent hashing capabilities built in The library includes a KetamaConnectionFactory class that implements consistent hashing By default consistent hashing is turned off in soymemcached For more information go to the KetamaConnectionFactory documentation at http dustin sallings org java memcached client apidocs net spy memcached KetamaConnectionFactory html Consistent Hashing Using PHP The ElastiCache Memcached PHP client is a wrapper around the built in Memcached PHP library By default consisten
75. will select the availability zones for your cluster s nodes The nodes will be distributed as evenly as practical across the availability zones that support your node type Specify Zones The console expands to list all the availability zones in your region that support this cluster s node type Behind each zone is a text box Type in the number of nodes you want launched in that availability zone Note The total of the values you type into these text boxes must equal then number of nodes you specified in the previous screen c Cache Security Groups or VPC Security Groups Select the security groups for this cluster If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more information about Amazon VPC security groups see http docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Security p 5 and Managing Cache Security Groups p 175 In the Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window Specify the day of the week to start maintenance the UTC time to start maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default We recommend speci
76. with the cluster is the configuration endpoint For more information on auto discovery see Node Auto Discovery Memcached p 116 To create a new Memcached cluster do the following Prerequisites 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard API Version 2015 02 02 89 Amazon ElastiCache User Guide Creating a Cluster Step 1 Select the Memcached Engine Before you proceed be sure you have completed the Prerequisites section To select your cluster s engine 1 2 On the Select Engine screen click the Memcached tab in Click Next Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Memcached Engine To configure your cluster s specifications and details 1 3 In the Cluster Specifications section of the Cluster Details page specify settings as shown following a b Engine Memcached Engine Version From the list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version Port Type a new port number for your cluster or leave it at its default value For Memcached the default port is 11211 Parameter Group From the list select a parameter group for this clust
77. you can t specify a particular ElastiCache resource in an IAM policy V rsion 20L2 10 17 Statement Effect Allow Action elasticache CreateCacheSecurityGroup elasticache DeleteCacheSecurityGroup elasticache DescribeCacheSecurityGroup elasticache AuthorizeCacheSecurityGroupIngress elasticache RevokeCacheSecurityGroupIngress Resource API Version 2015 02 02 203 Amazon ElastiCache User Guide Failure to Retrieve Account Attributes Example 2 Allow managers to only be able to list the current ElastiCache resources in the AWS Account In this example we create a policy that lets managers use the ElastiCache actions with Describe in the name Version 2012 10 17 Statement Effect Allow Action elasticache Describe Resource Example 3 Allow a system administrator to access a select set of ElastiCache actions In this example we create a policy that gives access to the relevant actions for system administrators and attach it to the group As with the other examples the resource is stated as because you can t specify a particular ElastiCache resource in an IAM policy Version 2012 10 17 Statement Effect Allow Action elasticache ModifyCacheCluster elasticache RebootCacheCluster lasticache DescribeCacheClusters lasticache DescribeEvents lasticache M
78. your cluster into EC2 Classic to allow an Amazon EC2 instance to access your cluster you will need to grant the Amazon EC2 security group associated with the instance access to your cache security group To grant an Amazon EC2 security group access to a cluster 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 From the left navigation pane click Cache Security Groups A list of cache security groups appears 3 Click the default security group 4 From the list at the bottom of the screen select the EC2 Security Group Name you want to authorize 5 Click Add to authorize access Amazon EC2 instances that are associated with the security group are now authorized to connect to your ElastiCache cluster To revoke a security group s access locate the security group in the list of authorized security groups and then click Remove Step 4 Connect to a Cluster Node This section assumes that you ve created an Amazon EC2 instance and can connect to it For instructions on how to do this go to the Amazon EC2 Getting Started Guide An Amazon EC2 instance can connect to a cluster node only if you have authorized it to do so For more information see Step 3 Authorize Access p 15 Once you ve authorized access to the cluster and your cluster is in the available state you can log in to an Amazon EC2 instance and connect to a node in the cluster To do so you must
79. your cluster s specifications and details 1 Inthe Cluster Specifications section of the Specify Cluster Details page specify settings as shown following a Engine Redis b Engine Version From the list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version c Cache Port Type a new port number for your cluster or leave it at its default value For Redis the default port is 6379 d Parameter Group From the list select a parameter group for this cluster Parameter groups control the run time parameters of your cluster For more information on parameter groups see Node Type Specific Parameters for Redis p 57 e Enable Replication To create a single Redis cluster uncheck this check box To create a Redis replication group see Creating a Redis Multiple Cluster Replication Group p 127 2 Inthe Configuration section of the Specify Cluster Details page specify settings as shown following a Cluster Name Type a meaningful name for this cluster Cluster name constraints are as follows A name must contain from 1 to 20 alphanumeric characters or hyphens e The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens Node Type From the list select the node type you want to use for this cluster For information on node types see Node Type Specific Parameters for Redis
80. 1T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Note When you create a new cache subnet group you should take note of the number of available IP addresses If the subnet has very few free IP addresses then you might be constrained as to how many more cache nodes you can add to the cache cluster To resolve this issue you can assign one or more subnets to a cache subnet group so that you have a sufficient number of IP addresses in your cluster s Availability Zone After that you can add more cache nodes to your cluster Assigning a Cache Subnet Group to a Cache Cluster Once you have created a cache subnet group you can launch a cache cluster in an Amazon VPC For more information go to Creating a Cache Cluster in an Amazon VPC p 167 Modifying a Cache Subnet Group You can modify a cache subnet group s description or modify the list of subnet IDs associated with the cache subnet group You cannot delete a subnet ID from a cache subnet group if a cache cluster is currently using that subnet The following procedures show you how to modify a cache subnet group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Subnet Groups In the list of cache subnet grou
81. 2 amp X Amz Credential lt credential gt For more information see AddTagsToResource in the ElastiCache API documentation You can also use the ElastiCache API to add tags to a cluster when you create a new cluster by using the CreateCacheClusier action Similarly you can use the ElastiCache API to add tags to a replication group when you create a new replication group by using the CreateReplicationGroup action Note that you cannot add tags during resource creation using the ElastiCache management console After a cluster or replication group is created you can then use the ElastiCache management console to add tags to the resource Listing the Tags for an ElastiCache Resource You can use the ElastiCache management console AWS CLI or ElastiCache API to list all the tags on a specified resource Topics ElastiCache Management Console p 69 AWS CLI p 69 ElastiCache API p 69 API Version 2015 02 02 68 Amazon ElastiCache User Guide ElastiCache Management Console ElastiCache Management Console You can use the ElastiCache management console to view which tags are on a resource To view the tags on a resource using the ElastiCache management console 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 Depending on the type of resource for which you want to see the current tags click Clusters or Snapshots 3
82. 20141201 us west 2 elasticache aws4_re quest amp X Amz Date 20141201T223649Z amp X Amz SignedHeaders content type host user agent x amz content sha256 x amz date amp X Amz Signa ture 2877960fced9040b41b4feaca835fddcfeb9264f768e6a0236c9143 915Fffa56 For detailed information on the signing process and calculating the request signature see the topic Signature Version 4 Signing Process and its subtopics Available Libraries AWS provides software development kits SDKs for software developers who prefer to build applications using language specific APIs instead of the Query API These SDKs provide basic functions not included in the APIs such as request authentication request retries and error handling so that it is easier to get started SDKs and additional resources are available for the following programming languages Java e Windows and NET PHP e Python e Ruby For information about other languages go to Sample Code amp Libraries Troubleshooting Applications ElastiCache provides specific and descriptive errors to help you troubleshoot problems while interacting with the ElastiCache API Retrieving Errors Typically you want your application to check whether a request generated an error before you spend any time processing results The easiest way to find out if an error occurred is to look for an Error node in the response from the ElastiCache API AP
83. 2015 02 02 129 Amazon ElastiCache User Guide Creating a Redis Replication Group If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more information about Amazon VPC security groups see http docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Security p 5 and Managing Cache Security Groups p 175 2 Inthe Backup section of the Configure Advanced Settings page specify settings as shown following Enable Automatic Backups To schedule regular automatic backups of your cluster check this check box When checked the console expands so you can specify how many days to keep an automatic backup before deleting when to start and how long for the backup window or allow ElastiCache select the time and duration Note By default ElastiCache designates your first read replica lt replicat ionGroupName gt 002 as the cluster from which backups are made You may modify this after the replication group is available For information on modifying a replication group see Modifying an Existing Redis Replication Group p 135 3 Inthe Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window The screen expands so you can specify the day
84. 2017T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This command should return a response similar to the following the following example has been truncated lt DescribeCacheParametersResponse xmlns http elasticache amazon aws com doc 2013 06 15 gt lt DescribeCacheParametersResult gt lt CacheClusterClassSpecificParameters gt lt CacheNodeTypeSpecificParameter gt lt DataType gt integer lt DataType gt lt Source gt system lt Source gt lt IsModifiable gt false lt IsModifiable gt lt Description gt The maximum configurable amount of memory to use to store items in megabytes lt Description gt lt CacheNodeTypeSpecificValues gt lt CacheNodeTypeSpecificValue gt lt Value gt 1000 lt Value gt lt CacheClusterClass gt cache cl medium lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt lt CacheNodeTypeSpecificValue gt lt Value gt 6000 lt Value gt lt CacheClusterClass gt cache cl xlarge lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt lt CacheNodeTypeSpecificValue gt lt Value gt 7100 lt Value gt lt CacheClusterClass gt cache ml large lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt lt CacheNodeTypeSpecificValue gt lt Value gt 1300 lt Value gt lt CacheClusterClass gt cache ml small lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt output omitted lt Cach
85. 2xlarge cache m2 4xlarge cache m3 medium cache m3 large cache m3 xlarge cache m3 2xlarge cache c1 xlarge cache r3 large cache r3 xlarge cache r3 2xlarge cache r3 4xlarge cache r3 8xlarge Note t2 instances do not support Redis backup restore Append Only Files AOF Note maxmemory 3461349376 943718400 3093299200 7025459200 14889779200 17091788800 35022438400 70883737600 2988441600 6501171200 14260633600 29989273600 6501171200 14470348800 30513561600 62495129600 126458265600 254384537600 Append only files AOF are not supported for cache t1 micro and cache t2 nodes For nodes of these types the appendon1y parameter value is ignored Note For Multi AZ replication groups AOF is disabled By default the data in a Redis node on ElastiCache resides only in memory and is not persistent If a node is rebooted or if the underlying physical server experiences a hardware failure the data in the cache is lost If you require data durability you can enable the Redis append onlly file feature AOF When this feature the node writes all of the commands that change cache data to an append only file When a node is rebooted the AOF is replayed when the Redis cache engine starts the result is a warm Redis cache with all of the data intact AOF is disabled by default To enable AOF for a cluster running Redis you must create a parameter group with the appendon1ly parameter set to yes and then assign th
86. 3d af48 11le0 97 9 279771c4477e lt RequestId gt lt ResponseMetadata gt lt DescribeCacheParameterGroupsResponse gt Viewing Parameter Values for a Cache Parameter Group You can get a detailed listing of all parameters in a cache parameter group and their values The following procedures show you how to view the parameter values for a specific cache parameter group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console amazonaws cn elasticache 2 Click Cache Parameter Groups in the navigation list on the left side of the window The available cache parameter groups appears in the Cache Parameter Groups list 3 Click on the cache parameter group that you want to see details for API Version 2015 02 02 158 Amazon ElastiCache User Guide Viewing Parameter Values for a Cache Parameter Group Details about the parameters in the selected cache parameter group are shown at the bottom of the console window You can use the navigation buttons at the top right of the detail panel to scroll through the available parameters You can filter the parameters shown by selecting an option from the Viewing drop down list box CLI Use the command elasticache describ specific cache parameter group cache parameters to view the parameter values for a PROMPT gt elasticache describ cache parameters myCacheParameterGroup headers
87. 49fd0c8 cf6d 47a0 bfab6 060f8e75e95f lt ReservedCacheNodesOfferingId gt lt State gt payment failed lt State gt lt ReservedCacheNodelId gt myreservationid lt ReservedCacheNodelId gt lt CacheNodeCount gt 1 lt CacheNodeCount gt lt StartTime gt 2010 12 15T00 25 14 1312 lt StartTime gt lt lt x Duration gt 31536000 lt Duration gt FixedPrice gt 227 5 lt FixedPrice gt UsagePrice gt 0 046 lt UsagePrice gt lt CacheNodeType gt cache ml small lt CacheNodeType gt lt ReservedCacheNode gt lt ReservedCacheNode gt output omitted lt ReservedCacheNode gt lt ReservedCacheNodes gt lt DescribeReservedCacheNodesResult gt lt ResponseMetadata gt lt Request Id gt 23400d50 2978 11lel 9e6d 771388d6ed6b lt RequestId gt lt ResponseMetadata gt lt DescribeReservedCacheNodesResponse gt Some of the output has been omitted for brevity Describing Available Reserved Cache Node Offerings Before you purchase a reserved cluster you can get information about available reserved cluster offerings The following example shows how to get pricing and information about available reserved cluster offerings API Version 2015 02 02 107 Amazon ElastiCache User Guide Managing Reserved Nodes AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache
88. 789012 user elasticache allow accountId 123456789012 accessKeyId AKIAIOSFODNN7EXAMPLE userName elasticache allow event Time 2014 12 01T22 01 002 eventSource elasticache amazonaws com eventName DescribeCacheClusters awsRegion us west 2 sourcelIPAddress 192 0 2 01 userAgent Amazon CLI ElastiCache 1 10 API 2014 12 01 requestParameters showCacheNodelInfo false maxRecords 100 responseElements null requestID 1f 0b5031 3548 11e4 9376 cl1d979ba565a event ID a58572a8 e81b 4100 8e00 1797ed19d172 The following example shows a CloudTrail log entry that records a ModifyCacheCluster action eventVersion 1 01 userIdentity type IAMUser orincipallId EXAMPLEEXAMPLEEXAMPLE arn arn awsS iam 123456789012 user elasticache allow accountId 123456789012 accessKeyId AKIAIOSFODNN7EXAMPLE userName elasticache allow API Version 2015 02 02 198 Amazon ElastiCache User Guide Understanding ElastiCache Log File Entries event Time 2014 12 01T22 32 212 eventSource elasticache amazonaws com eventName ModifyCacheCluster awsRegion us west 2 sourcelIPAddress 192 0 2 01 userAgent Amazon CLI ElastiCache 1 10 API 2014 12 01 requestParameters applyImmediately true numCacheNodes 3 cacheCl
89. Amazon ElastiCache User Guide ElastiCache API The resource name parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt PROMPT gt aws elasticache remove tags from resource resource name arn aws elasticache us west 2 0123456789 cluster myCluster tag keys Service Region ElastiCache API You can use the ElastiCache API to remove tags from an existing ElastiCache resource by using the RemoveTagsFromResource action The following code uses the ElastiCache API to remove the tags with the keys Service and Region from the resource myCluster in the us west 2 region The ResourceName parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt https elasticache us west 2 amazonaws com Action RemoveTagsFromResource amp ResourceName arn aws elasticache us west 2 0123456789 cluster myCluster amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp TagKeys member 1 Servic amp TagKeys member 2 Region amp Version 2015 02 02 amp Timestamp 20150202T1923172Z amp X Amz Credential lt credential gt Copying Tags to Your ElastiCache Resources When you perform certain operations on your ElastiCache resources using the ElastiCache API or AWS CLI if tags exist on the resource the tags are copied
90. Availability Zone to associate with this cache subnet group In the Subnet ID box select one of the subnets in your VPC and then click Add You can repeat this step as many times as necessary to add more subnets to your cache subnet group 9 Click the Yes Create button Your cache subnet group is now ready to use ON Gre NM CLI Use the command elasticache create cache subnet to create a cache subnet group PROMPT gt elasticache create cache subnet group mycachesubnetgroup description Testing subnet ID list subnet 53df9c3a This command should produce output similar to the following SUBNETGROUP mycachesubnetgroup Testing vpc 5a2e4c35 SUBNET subnet 53df9c3a us west 2b API Call createCacheSubnet Group with the following parameters e CacheSubnetGroupName mycachesubnetgroup API Version 2015 02 02 171 Amazon ElastiCache User Guide Assigning a Cache Subnet Group to a Cache Cluster e CacheSubnetGroupDescription Testing e SubnetIds member 1 subnet 53df9c3a Example https elasticache us west 2 amazonaws com Action CreateCacheSubnet Group amp CacheSubnetGroupName mycachesubnetgroup amp CacheSubnetGroupDescription Testing amp SubnetIds member 1 subnet 53df9c3a amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS4 HMAC SHA256 amp X Amz Date 2014120
91. C 0 0 2 0 ccceceeneeeee cece eee eeeeeeeeeeeeeeseeeeeseeseeseeseeaeeeeeaes 16 You Launched Your Cluster into EC2 Classic ccceeeeeneeeeeeeeeeeneeeeeseeeeeneeeeeaeeaeeaeeaeeaes 17 Step 4 Connect to a Cluster Node cccccccececeec eee eceeeeceeeeceeeeeeeeeeeceeeeeeeaeaeeeeaeeeeeseseesneeeaeees 17 Step 4 Connect to a Memcached Node ccccceceececeeceeeeceeeeeeeeeeeceeeeseeeeseeeeeeeeeeeeeeaees 18 Step 4 Connect to a Redis Cluster 0 ccc cece cee ece ec ee eee eeeeeeee sense eeeeaeeeeneeeeeseeseeeeeeeeeanees 19 Step 5 Delete Your Cache Cluster cccceceecec eee ec eee eceee eens eceeeeneeeeeeseeeeseeaeeeeeeeeeeseeseeseeeeeees 21 Where Dol Go From Hote cscs cc2cc28 sccneancndeanedecst aideneeegtandatewadunt sa ptenandentnveacanewhelebageteendenseseastd 21 Best Practices for Implementing Amazon ElastiCache ccceeeceeeeeceeeeeeeeeeeceeeeeseeceeseeseeseeeeeeeeneeaes 22 Ensuring That You Have Sufficient Memory to Create a Redis Snapshot ccceeeeeeeeeneeeeea teens 22 BGSAVE Process and Memory Usage eceeeceeeeeeeeeeeeeeeeee eee ese eeeeseeeeeseeseeeeeeeeaeenees 22 Avoiding Running Out of Memory When Executing BGSAVE ceceeeeeeeeeeeeeeeeeeeeeeeeeeenes 23 Fault Tolerance AOF or Multi AZ 0 0 0 0 ccc cee cece eee e eee ee ee ee ee ee een etre neta een eee eeneeaeeae 24 Enabling Redis AOF for Fault Tolerance ccceceeeeeeeeecee
92. Cache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard Step 1 Select the Redis Engine Before you proceed be sure you have completed the Prerequisites section To select your cluster s engine 1 On the Select Engine screen click the Redis tab FA 2 Click Next Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Redis Engine API Version 2015 02 02 93 Amazon ElastiCache User Guide Creating a Cluster To configure your cluster s specifications and details 1 3 In the Cluster Specifications section of the Specify Cluster Details page specify settings as shown following a Engine Redis b Engine Version From the list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version c Cache Port Type a new port number for your cluster or leave it at its default value For Redis the default port is 6379 d Parameter Group From the list select a parameter group for this cluster Parameter groups control the run time parameters of your cluster For more information on parameter groups see Node Type Specific Parameters for Redis p 57 e Enable Replication To create a single Redis cluster uncheck this check box To create a Redis replicati
93. Dive into Amazon ElastiCache Architecture and Design Patterns AWS re Invent 2013 SDD402 Amazon ElastiCache Deep Dive re Invent 2014 In this video we examine common caching use cases the Memcached and Redis engines patterns that help you determine which engine is better for your needs consistent hashing and more as means to building fast scalable applications Frenk Wiebe Principal Scientist at Adobe details how Adobe uses Amazon ElastiCache to improve customer experience and scale their business DAT402 Amazon ElastiCache Deep Dive re Invent 2014 Are You a First Time ElastiCache User If you are a first time user of ElastiCache we recommend that you begin by reading the following sections Service Highlights and Pricing The product detail page provides a general product overview of ElastiCache service highlights and pricing e Getting Started The Getting Started with Amazon ElastiCache p 8 section includes an example that walks you through the process of creating a cache cluster authorizing access to the cache cluster connecting to a cache node and deleting the cache cluster After you complete the Getting Started section you can read these sections to learn more about ElastiCache administration e ElastiCache Terminology and Concepts p 26 This section explains the components of a cache cluster including cache nodes cache engines replication groups and cache cluster security Creating a Cl
94. Group amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T1923172 amp X Amz Credential lt credential gt When you create the clusters and replication group as shown in this example the names of the clusters are created by adding a three digit sequential number starting at 001 to the end of the replication group s names For more information see http docs amazonaws cn AmazonElastiCache latest AP Reference API_ModifyReplicationGroup html Backup and Restore for Redis Clusters Topics Constraints p 39 Costs p 39 Automatic Snapshots p 39 Manual Snapshots p 39 Performance Impact of Snapshots p 40 Restoring From a Snapshot p 40 Deleting Snapshots p 41 Amazon ElastiCache clusters running Redis can use snapshots for backing up and restoring data A snapshot is a backup copy of a node at a specific moment in time The snapshot consists of the cluster API Version 2015 02 02 38 Amazon ElastiCache User Guide Constraints metadata along with all of the data in the node All snapshots are written to Amazon Simple Storage Service Amazon S3 which provides durable storage At any time you can restore your data by creating a new Redis cluster and populating it with data from a snapshot ElastiCache lets you manage snapshots using the AWS Management Console the ElastiGache command line interface CLI and the ElastiCache applicatio
95. I Version 2015 02 02 191 Amazon ElastiCache User Guide Troubleshooting Tips XPath syntax provides a simple way to search for the presence of an Error node as well as an easy way to retrieve the error code and message The following code snippet uses Perl and the XML XPath module to determine if an error occurred during a request If an error occurred the code prints the first error code and message in the response use XML XPath my xp XML XPath gt new xml gt Sresponse if Sxp gt find Error print There was an error processing your request n Error code Sxp gt findvalue Error 1 Code n Sxp gt findvalue Error 1 Message n n Troubleshooting Tips We recommend the following processes to diagnose and resolve problems with the ElastiCache API e Verify that ElastiCache is running correctly To do this simply open a browser window and submit a query request to the ElastiCache service such as https elasticache amazonaws com A MissingAuthenticationTokenException or 500 Internal Server Error confirms that the service is available and responding to requests e Check the structure of your request Each ElastiCache operation has a reference page in the ElastiCache API Reference Double check that you are using parameters correctly In order to give you ideas regarding what might be wrong look at the sample requests or user scenarios to see if those examples
96. Id my restored redis amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 150 Amazon ElastiCache User Guide Migrating Your Redis Cluster to ElastiCache Migrating Your Redis Cluster to ElastiCache When you create a new Redis cluster you can seed it with data from a Redis rdb snapshot file Seeding the cluster is useful if you currently manage a Redis instance outside of ElastiCache and want to populate your new ElastiCache cluster with your existing Redis data Important You must ensure that your Redis snapshot data does not exceed the resources of the node For example you cannot upload an rdb file with 2 GB of Redis data to a cache m1 small node that has 1 3 GB of memory If the snapshot is too large the resulting cluster will have a status of restore failed If this happens you must delete the cluster and start over For a complete listing of node types and specifications see Node Type Specific Parameters for Redis p 57 and Amazon ElastiCache Product Features and Details Create a Redis Snapshot To create the Redis snapshot from which you will seed your ElastiCache Redis
97. M with ElastiCache doesn t change how you use ElastiCache cache security groups to grant access to cache clusters However you can use IAM policies to specify which ElastiCache actions a User in your AWS Account can use with ElastiCache resources in general Because you can t specify a particular cache cluster in the policy you must specify as the resource to indicate all cache clusters in the AWS Account Example You could create a policy that gives the Developers group permission to use only these APIs CreateCacheCluster DescribeCacheClusters ModifyCacheCluster RebootCacheCluster DeleteCacheCluster DescribeEvents They could then use those APIs with any cache cluster that belongs to your AWS Account For examples of IAM policies that cover ElastiCache actions see Example Policies for ElastiCache p 203 ElastiCache Resources and IAM When you create an IAM policy for ElastiCache you can t use an ElastiCache Amazon Resourc Name ARN to scope your policy to particular ElastiCache resources In the Resource section of the policy you must use the wildcard character which applies the policy permissions to all your ElastiCache resources Instead you scope your policy to specific actions as described following For more information about IAM go to the IAM User Guide documentation ElastiCache Actions and IAM When you create an IAM policy for ElastiCache your policy is scoped to specific actions not resources Th
98. MPT gt elasticache delete replication group my repgroup You will be asked to confirm your decision if you enter y yes the operation will begin immediately Once you begin deleting this replication group all of its clusters will be deleted as well Are you sure you want to delete this replication group Nyly REPLICATIONGROUP my repgroup My replication group deleting API Call DeleteReplicationGroup with the ReplicationGroup parameter API Version 2015 02 02 137 Amazon ElastiCache User Guide Deleting a Replication Group Example https elasticache us west 2 amazonaws com Action DeleteReplicationGroup amp ReplicationGroupId my repgroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 201412017T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Note If you set the RetainPrimaryCluster parameter to true all of the read replicas will be deleted but the primary cache cluster will be retained API Version 2015 02 02 138 Amazon ElastiCache User Guide Managing Backup and Resiore Redis Managing Backup and Restore Redis This section covers backup and restore operations using Redis cluster snapshots You can use the Amazon
99. Met hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Enabling Automatic Snapshots for an Existing Cluster The following sections contain procedures showing you how to enable automatic snapshots on an existing cluster AWS Management Console To enable automatic snapshots on an existing cluster using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Cache Clusters In the list of clusters find the Redis cluster that you want to change and click Modify 4 Inthe Modify Cache Cluster dialog set Enable Automatic Backups to Yes w In the Backup Retention Period drop down list select the number of days that you want to retain your daily snapshots Note The backup retention period must be greater than zero 0 days to enable backups Select the time range during which your daily backups will be made 5 Click the Modify button CLI To enable automatic snapshots for an existing cluster use the elast icache modify cache cluster command The following example enables automatic snapshots by setting snapshot retention limit to a nonzero value i
100. New guide Description Date Changed In this release ElastiCache clusters can be launched in December 20 2012 Amazon Virtual Private Cloud VPC By default new customers cache clusters are created in an Amazon VPC automatically existing customers can migrate to Amazon VPC at their own pace For more information see ElastiCache and Amazon Virtual Private Cloud p 60 and Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 ElastiCache provides cache node auto discovery the November 28 2012 ability for client programs to automatically determine all of the cache nodes in a cluster and to initiate and maintain connections to all of these nodes This release also offers a new cache engine version Memcached version 1 4 14 This new cache engine provides enhanced slab rebalancing capability significant performance and scalability improvements and several bug fixes There are several new cache parameters that can be configured For more information see This release provides four additional cache node types November 13 2012 This release adds support for reserved cache nodes April 5 2012 This is the first release of Amazon ElastiCache User Guide August 22 2011 API Version 2015 02 02 215 Amazon ElastiCache User Guide AWS Glossary For the latest AWS terminology see the AWS Glossary in the AWS General Reference API Version 2015 02 02 216
101. Notifications API Version 2015 02 02 196 Amazon ElastiCache User Guide Understanding ElastiCache Log File Entries You can also aggregate ElastiCache log files from multiple AWS regions and multiple AWS accounts into a single Amazon S3 bucket For more information see Aggregating CloudtTrail Log Files to a Single Amazon S3 Bucket Understanding ElastiCache Log File Entries CloudTrail log files can contain one or more log entries where each entry is made up of multiple JSON formatted events A log entry represents a single request from any source and includes information about the requested action any parameters the date and time of the action and so on The log entries are not guaranteed to be in any particular order That is they are not an ordered stack trace of the public API calls The following example shows a CloudTrail log entry that records a CreateCacheCluster action eventVersion 1 01 useriIdentity type IAMUser orincipallId EXAMPLEEXAMPLEEXAMPLE arn arn awsS iam 123456789012 user elasticache allow accountId 123456789012 accessKeyId AKIAIOSFODNN7EXAMPLE userName elasticache allow Fs eventTime 2014 12 01IT22 00 352 eventSource elasticache amazonaws com eventName CreateCacheCluster awsRegion us west 2 sourceIPAddress 192 0 2 01 userAgent Amazon CLI ElastiCache 1 10 API 2014 12 01 requestParamet
102. PI Version 2015 02 02 49 Amazon ElastiCache User Guide Parameters for Redis Name notify keyspace events Default Type Modifi able an string Yes empty string Description The types of keyspace events that Redis can notify clients of Each event type is represented by a single letter e K Keyspace events pub lished with a prefix of __key space lt db gt __ e E Key event events pub lished with a prefix of __keyevent lt db gt __ g Generic non specific commands such as DEL EX PIRE RENAME etc String commands List commands s Set commands h Hash commands z Sorted set commands x Expired events events generated every time a key ex pires e Evicted events events generated when a key is evicted for maxmemory A An alias for g ishzxe You can have any combination of these event types For example AKE means that Redis can pub lish notifications of all event types Do not use any characters other than those listed above attempts to do so will result in error mes sages By default this parameter is set to an empty string meaning that keyspace event notification is dis abled API Version 2015 02 02 50 Amazon ElastiCache User Guide Parameters for Redis Name Default Type Modifi able repl backlog size 1048576 integer Yes repl backlog ttl 3600 integer Yes repl timeout 60 integer Yes Redis 2 6 13 Parameters
103. SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 115 Amazon ElastiCache User Guide Managing Nodes Managing Nodes A node is the smallest building block of an ElastiCache deployment It is a fixed size chunk of secure network attached RAM Each cache node runs an instance of either Memcached or Redis depending on what was selected when the cluster was created Each cache node has its own Domain Name Service DNS name and port Multiple types of cache nodes are supported each with varying amounts of associated memory For information on selecting a node type for your deployment go to Node Considerations for Memcached p 27 Node Considerations for Redis p 29 e Reserved Nodes p 29 Topics e Node Auto Discovery Memcached p 116 e Actions You Can Take When a Node is Scheduled for Replacement p 125 Node Auto Discovery Memcached Note Auto Discovery is only available for cache clusters running the Memcached engine Redis cache clusters are single node clusters thus there is no need to identify and track all the nodes in a Redis cluster ElastiCache supports Auto Discovery the ability for client programs to au
104. T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Note When you create a new cache subnet group you should take note of the number of available IP addresses If the subnet has very few free IP addresses then you might be constrained as to how many more cache nodes you can add to the cache cluster To resolve this issue you can assign one or more subnets to a cache subnet group so that you have a sufficient number of IP addresses in your cluster s Availability Zone After that you will be able to add more cache nodes to your cluster API Version 2015 02 02 173 Amazon ElastiCache User Guide Deleting a Cache Subnet Group Deleting a Cache Subnet Group If you decide that you no longer need your cache subnet group you can delete it You cannot delete a cache subnet group if it is currently in use by a cache cluster The following procedures show you how to delete a cache subnet group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Subnet Groups In the list of cache subnet groups select the one you want to delete and then click Delete 4 When you are asked to confirm this operation click Yes Delete w CLI Use the command elasticache delete cache subnet group to delete a cache subnet group
105. The following list identifies those operations and what copying occurs CopySnapshot or copy snapshot When you make a copy of a snapshot if there are any tags on the source snapshot they are copied to the copy e CreateSnapshot or create snapshot When you create a snapshot if there are any tags on the source cluster they are copied to the snapshot e RestoreFromSnapshot or restore from snapshot When you restore a cluster from a snapshot created by ElastiCache if there are any tags on the snapshot they are copied to the restored cluster DeleteSnapshot or delete snapshot When you delete a snapshot if there are any tags on the snapshot they are deleted with the snapshot e DeleteCluster or delete cluster When you delete a cluster any tags on the cluster are deleted with the cluster However if you make a final snapshot the tags are copied to the snapshot API Version 2015 02 02 73 Amazon ElastiCache User Guide Dimensions for ElastiCache Metrics CloudWatch Metrics with ElastiCache Topics Dimensions for ElastiCache Metrics p 74 Choosing Metric Statistics and Periods p 75 Host Level Metrics p 75 Metrics for Memcached p 75 Metrics for Redis p 78 Which Metrics Should Monitor p 79 ElastiCache provides metrics that enable you to monitor your cache clusters You can access these metrics through CloudWatch For more information on CloudWatch go to the CloudWatch documentat
106. The number of expired items reclaimed from the LRU which were never touched after being set The total number of slab pages that have been moved The number of keys that have been touched and were given a new expiration time The number of items that have been touched but were not found The following table describes the available calculated cache level metrics Metric NewConnections Newltems UnusedMemory Description The number of new connections the cache has re ceived This is derived from the memcached total_connections statistic by recording the change in total_connections across a period of time This will always be at least 1 due to a connection re served for a ElastiCache The number of new items the cache has stored This is derived from the memcached total_items statistic by recording the change in total_items across a period of time The amount of unused memory the cache can use to store items This is derived from the memcached statistics limit_maxbytes and bytes by subtracting bytes from limit_maxbytes Unit Count Unit Bytes Count Count Count Count Count Count Count Count Count Unit Count Count Bytes API Version 2015 02 02 77 Amazon ElastiCache User Guide Metrics for Redis Metrics for Redis The following table lists the metrics provided by ElastiCache With the exception of ReplicationLag these metrics are derived from the Redis info command Each metri
107. This section describes how to create the signature The method described in the following procedure is known as signature version 4 The following are the basic steps used to authenticate requests to AWS This assumes you are registered with AWS and have an Access Key ID and Secret Access Key API Version 2015 02 02 189 Amazon ElastiCache User Guide Query Request Authentication Query Authentication Process 1 The sender constructs a request to AWS 2 The sender calculates the request signature a Keyed Hashing for Hash based Message Authentication Code HMAC with a SHA 1 hash function as defined in the next section of this topic 3 The sender of the request sends the request data the signature and Access Key ID the key identifier of the Secret Access Key used to AWS 4 AWS uses the Access Key ID to look up the Secret Access Key 5 AWS generates a signature from the request data and the Secret Access Key using the same algorithm used to calculate the signature in the request 6 If the signatures match the request is considered to be authentic If the comparison fails the request is discarded and AWS returns an error response Note If a request contains a Timestamp parameter the signature calculated for the request expires 15 minutes after its value If a request contains an Expires parameter the signature expires at the time specified by the Expires parameter For example the following is a sample request
108. To launch this cluster outside a VPC click Not in VPC The cluster will be launched in the AWS public cloud API Version 2015 02 02 94 Amazon ElastiCache User Guide Creating a Cluster 2 3 4 Availability Zones From the drop down list select the availability zone for this cluster To have ElastiCache select the zone for you select No Preference Cache Security Groups or VPC Security Groups Select the security groups for this cluster If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more information about Amazon VPC security groups see htip docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Security p 5 and Managing Cache Security Groups p 175 In the Backup section of the Configure Advanced Settings page specify settings as shown following Enable Automatic Backups To schedule regular automatic backups of your cluster check this check box e Unchecked Default Leaving this unchecked means that ElastiCache will not schedule automatic backups of this cluster If you want a backup you must create a manual backup For more information see Creating a Manual Snapshot p 146 Checked Checking this checkbox causes ElastiCache to schedule regular automatic backups of this cluster You can also perform manual backups if you so choose When thi
109. Version 2015 02 02 29 Amazon ElastiCache User Guide Replication Groups and Read Replicas Redis paying for your cache node when you shut it off Medium Utilization reserved cache nodes are a more cost effective option when you plan to run more than 40 percent of the reserved cache nodes term This option can save you up to 64 percent off of the On Demand price With Medium Utilization reserved cache nodes you pay a slightly higher one time fee than with Light Utilization reserved cache nodes and you receive lower hourly usage rates when you run a cache node Light Utilization reserved cache nodes are ideal for periodic workloads that run only a couple of hours a day or a few days per week Using Light Utilization reserved cache nodes you pay a one time fee followed by a discounted hourly usage fee when your cache node is running You can start saving when your cache node is running more than 17 percent of the reserved cache node term and you can save up to 56 percent off of the On Demand rates over the entire term of your reserved cache node Remember that discounted usage fees for reserved cache node purchases are tied to cache node type If you shut down a running cache node on which you have been getting a discounted rate as a result of a reserved cache node purchase and the term of the reserved cache node has not yet expired you will continue to get the discounted rate if you launch another cache node with the same specifications during
110. ache Cluster Clients ccceeeeeee cece e eee e eee teeta eee ee deta e eae eae ease eeaeeaeeaeeaeeaeeaeeaeeaeeaes 206 Installing the ElastiCache Cluster Client for PHP ccceeeeeeeee eee eee eee eeeeeeeeeeeaeeseeeeeeeeaeeeeenee 206 Downloading the Installation Package cceeeeeeeee eee eee nett eee ee eee eee eea een een eee eea een een eee eees 206 Installation Steps for New Users ccceeeeeeeee cece ee eee eee een eee eee eaeeseeaeeseeseeseeseeseeeeeaeeeees 207 For Users Who Already Have pho memcached Extension Installed csceeeeeeeeeeeeeees 210 Removing the PHP Cluster Client cc cececeeee eet eee eee rene etter nent een eed 210 Installing the ElastiCache Cluster Client for NET cceeeeeee eee eeeeeeeeeeeeeeeeeeeeeeeseeeeeseeeeeeeenees 210 Installing NET 3 sciiceevesadch rverectes winch ie Mae atict dees Ee E AN teeta 210 Download the ElastiCache NET Cluster Client for ElastiCache cceeeeeeeeeeeeeeeeee eee eeee 210 Install AWS Assemblies with NUGet cece cee ence eect eee eee eee a esas eee a neat eee a eee eeaeeaeeaeea eed 211 DOCUMENT Stry nanai alitvers ace tec ted Bae e e eta eae ad ate aa eee eee ae a ae 212 AWS GIOSSARY re ri dite siete ea Ge ea aks eats erent eed E E eh ees dina aoa eee aes a rede eein eae 216 API Version 2015 02 02 vi Amazon ElastiCache User Guide What Is Amazon ElastiCache Welcome to the Amazon
111. ache cluster Client programs poll the cluster once per minute this interval can be adjusted if necessary If there are any changes to the cluster configuration such as new or deleted nodes the client receives an updated list of metadata The client then connects to or disconnects from these nodes as needed Auto Discovery is enabled on all ElastiCache Memcached cache clusters You do not need to reboot any of your cache nodes to use this feature To begin using Auto Discovery follow these steps API Version 2015 02 02 116 Amazon ElastiCache User Guide Node Auto Discovery Memcached Step 1 Obtain the Configuration Endpoint p 117 Step 2 Download the ElastiCache Cluster Client p 117 e Step 3 Modify Your Application Program p 118 Step 1 Obtain the Configuration Endpoint To connect to a cluster client programs must know the cluster configuration endpoint You can obtain the configuration endpoint using the AWS Management Console Launch Cache Cluster mycachecluster Configuration Endpoint inycacheciuster1 b47 tf cfg uset cache amazonaws com 1121T 2 nodes cache m1 large Created on Thu Fei Uirtir0ess On see 20 available Engine memcached Availability Zone us east 1a Modify Reboot mycachecluster2 Configuration Endpoint nycacheciuster2 b47 tf cfg use1 cache amazonaws com 11217 2 nodes cache m1 large Created on Thu FebDUS tia03 e mS available Engine memcached Availability Zone us east ta M
112. ache cluster by using Amazon VPC security groups The Amazon VPC must allow non dedicated Amazon EC2 instances You cannot use ElastiCache in an Amazon VPC that is configured for dedicated instance tenancy Note ElastiCache is fully integrated with Amazon Virtual Private Cloud VPC For ElastiCache users this means the following If your AWS account supports only the EC2 VPC platform ElastiCache will always launch your cluster in a VPC If you re new to ElastiCache your clusters will be deployed into a VPC A default VPC will be created for you automatically If you have a default VPC and don t specify a subnet when you launch a cluster the cluster launches into your default VPC You can launch clusters into your default VPC without needing to know anything about Amazon VPC Your experience with clusters that you launch is the same whether you have a default VPC or not For more information see Detecting Your Supported Platforms and Whether You Have a Default VPC This section explains how to manually configure an ElastiCache cluster in an Amazon VPC This information is intended for users who want a deeper understanding of how ElastiCache and Amazon VPC work together Topics e Creating a Virtual Private Cloud VPC p 164 Creating a Cache Subnet Group p 166 e Creating a Cache Cluster in an Amazon VPC p 167 e Connecting to a Cache Cluster Running in an Amazon VPC p 167 Creating a Virtual Private Cloud VPC
113. ache security group is created Note that Amazon EC2 instances running in an Amazon VPC are unable to connect to ElastiCache cache clusters in EC2 Classic Creating a Cache Security Group To create a cache security group you need to provide a name and a description The following procedures show you how to create a new cache security group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Security Groups 3 Click Create Cache Security Group The Create Cache Security Group window appears 4 Type the name of the new cache security group in the Cache Security Group text box Type a description for the new cache security group in the Description text box 6 Click Create o CLI Use the command elasticache create cache security group With the following parameters PROMPT gt elasticache create cache security group mycachesecuritygroup d My new security group API Call CreateCacheSecurityGroup With the following parameters e CacheSecurityGroupName mycachesecuritygroup e Description My new security group API Version 2015 02 02 175 Amazon ElastiCache User Guide Listing Available Cache Security Groups Example https elasticache us west 2 amazonaws com Action CreateCacheSecurityGroup amp CacheSecurityGroupName mycachesecuritygroup
114. ad replicas per replication group so you can repeat these steps as necessary AWS Management Console To add a read replica to an existing Redis replication group 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache In the left navigation pane click Replication Groups In the Replication Groups list click the box to the left of the replication group you want to modify Click Add Read Replica In the Add Read Replica to Replication Group dialog box do the following When all the settings are as you want them click Add oP oN a Inthe Read Replica ID box type a name for your read replica b Optional In the Availability Zone drop down list click the availability zone you want this cluster created in ElastiCache will create your read replica cluster and add it to the replication group This process will take a few minutes When the process is complete the replica will be displayed in the Replication Groups panel Its current role will be listed as read replica CLI To add a read replica to an existing replication group use the elasticache create cache cluster command with the replicat ion group id option The following example creates a new cache cluster named my replica 1 and adds it to the my repgroup replication group PROMPT gt elasticache create cache cluster my replica 1l replication group id my repgroup This command produces
115. ame mycacheparametergroup amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This command should return a response similar to the following lt ModifyCacheParameterGroupResponse xmlns http elasticache amazon aws com doc 2013 06 15 gt lt ModifyCacheParameterGroupResult gt lt CacheParameterGroupName gt mycacheparametergroup lt CacheParameterGroupName gt lt ModifyCacheParameterGroupResult gt lt ResponseMetadata gt lt Request Id gt fcedeef2 b7ff 11e0 9326 b7275b9d4a6c lt RequestId gt lt ResponseMetadata gt lt ModifyCacheParameterGroupResponse gt API Version 2015 02 02 163 Amazon ElastiCache User Guide Using ElastiCache with Amazon Virtual Private Cloud VPC Using ElastiCache with Amazon Virtual Private Cloud VPC The Amazon Virtual Private Cloud VPC service defines a virtual network that closely resembles a traditional data center You can configure your Amazon VPC you can select its IP address range create subnets and configure route tables network gateways and security settings You can add a cache cluster to the virtual network and you can control access to the c
116. are doing similar operations e Check the forum ElastiCache has a discussion forum where you can search for solutions to problems others have experienced along the way To view the forum go to https forums aws csdn net API Version 2015 02 02 192 Amazon ElastiCache User Guide Event Notifications and Amazon SNS ElastiCache can publish messages using Amazon Simple Notification Service SNS when significant events happen on a cache cluster This feature can be used to refresh the server lists on client machines connected to individual cache node endpoints of a cache cluster Note For more information on Amazon Simple Notification Service SNS including information on pricing and links to the Amazon SNS documentation go to the Amazon SNS product page Notifications are published to a specified Amazon SNS topic Only one topic can be configured for ElastiCache notifications and the AWS account that owns the Amazon SNS topic must be the same account that owns the cache cluster on which notifications are enabled The following ElastiCache events trigger Amazon SNS notifications Event Name ElastiCache AddCacheNodeComplete ElastiCache AddCacheNodeFailed due to insuffi cient free IP addresses ElastiCache CacheClusterParametersChanged ElastiCache CacheClusterProvisioningComplete ElastiCache CacheClusterProvisioningFailed due to incompatible network state Description A cache node has been added to th
117. ary with replicas in a replication group e When enabling the append only file feature AOF for Redis e When promoting a replica to master which causes a primary replica sync Whenever Redis executes BGSAVE you must have sufficient available memory to accommodate the process overhead Failure to have sufficient memory available will cause the process to fail Because of this it is important to select a node instance type that has sufficient memory when creating your Redis cluster BGSAVE Process and Memory Usage Whenever BGSAVE is called Redis forks its process remember Redis is single threaded One fork persists your data to disk in a Redis rdb snapshot file The other fork services all read and write operations In order to ensure that your snapshot is a point in time snapshot all write operations are written to an area of available memory separate from the data area API Version 2015 02 02 22 Amazon ElastiCache User Guide Avoiding Running Out of Memory When Executing BGSAVE As long as you have sufficient memory available to record all write operations while the data is being persisted to disk you will have no insufficient memory issues You are likely to experience insufficient memory issues if any of the following are true e Your application performs many write operations thus requiring a large amount of available memory to accept the new or updated data e You have very little memory available in which to w
118. asing the total available memory in your cluster You will need to obtain an updated endpoint list from the ElastiCache CLI API or AWS Management Console and configure your clients to use the additional node s If your cluster turns out to be bound by CPU but has sufficient hit rate then try setting up a new cluster with a different cache node type ElastiCache supports adding or removing cache nodes from an existing cluster using the AWS Management Console the API and the command line tools allowing you to increase both the memory and compute capacity of the cluster at any time API Version 2015 02 02 27 Amazon ElastiCache User Guide Node Considerations for Memcached Note ElastiCache does not currently support dynamically changing the cache node type for a cluster after it has been created If you want to change the node type of a cluster you will need to set up a new cluster with the desired node type and migrate your application to that cluster You can scale a Memcached cluster by adding or deleting nodes For more information see Adding or Removing Nodes p 96 Availability Zone Considerations Distributing your Memcached nodes over multiple Availability Zones within a region helps protect you from the impact of a catastrophic failure such as a power loss within an Availability Zone A Memcached cluster can have up to 20 nodes When you create or add nodes to your Memcached cluster you can specify a single Availa
119. astiCache allows you to control access to your cache clusters using cache security groups A cache security group acts like a firewall controlling network access to your cache cluster Important ElastiCache uses cache security groups to control who has access to specific ElastiCache cache clusters There s no way in the IAM system to allow or deny access to a specific cache cluster For more information about using security groups with ElastiCache refer to the Amazon ElastiCache User Guide About IAM Amazon ElastiCache integrates with AWS Identity and Access Management IAM a service that enables you to do the following e Create users and groups under your AWS account e Easily share your AWS resources between the users in your AWS account e Assign unique security credentials to each user e Control each user s access to services and resources e Get a single bill for all users in your AWS account API Version 2015 02 02 200 Amazon ElastiCache User Guide ElastiCache Security Groups and IAM For example you can use IAM with ElastiCache to control which Users in your AWS Account can create or modify cache clusters for your AWS Account For more information about IAM see the following e Identity and Access Management IAM IAM Getting Started Guide e IAM User Guide For more information on using IAM with ElastiCache see Controlling ElastiCache Access with IAM p 200 ElastiCache Security Groups and IAM Using IA
120. at parameter group to your cluster You can also modify the appendfsync parameter to control how often Redis writes to the AOF file API Version 2015 02 02 58 Amazon ElastiCache User Guide Subnet Groups For more information see the following sections Parameter Groups p 43 e Parameters for Redis p 48 Managing Cache Parameter Groups p 155 Warning AOF cannot protect against all failure scenarios For example if a node fails due to a hardware fault in an underlying physical server ElastiCache will provision a new node on a different server In this case the AOF file will no longer be available and cannot be used to recover the data Thus Redis will restart with a cold cache Tip For greater reliability and faster recovery we recommend that you create one or more read replicas in different availability zones for your cluster and enable Multi AZ on the replication group instead of using AOF AOF is disabled for Multi AZ replication groups For more information see the following sections Fault Tolerance AOF or Multi AZ p 24 e Replication Groups and Read Replicas Redis p 30 Managing Replication Groups p 127 Subnet Groups A subnet group is a collection of subnets typically private that you can designate for your clusters running in an Amazon Virtual Private Cloud VPC environment If you create a cluster in an Amazon VPC then you must specify a cache subnet group ElastiCache uses
121. ations if the number of available replicas drops below a user specified threshold Redis 2 8 6 lets you specify the minimum number of replicas that must be available You can also specify the number of seconds within which the primary must receive pings from the replica or else stop accepting write operations Event notifications with Redis publish and subscribe Redis clients can subscribe to server side events of interest for example when an item is added to the cache When an event of interest occurs Redis publishes notifications to clients that are subscribed to these events You can specify the types of events that Redis publishes For more information go to http redis io topics notifications Redis 2 6 13 Redis 2 6 13 was the first release supported by ElastiCache API Version 2015 02 02 42 Amazon ElastiCache User Guide Regions and Availability Zones Regions and Availability Zones AWS cloud computing resources are housed in highly available data center facilities To provide additional scalability and reliability these data center facilities are located in several different physical locations These locations are categorized by regions and Availability Zones Regions are large and widely dispersed into separate geographic locations Availability Zones are distinct locations within a region that are engineered to be isolated from failures in other Availability Zones and provide inexpensive low latency network connectivi
122. ber of commands that are key based Count This is derived from the Redis commandstats stat istic by summing all of the commands that act upon one or more keys API Version 2015 02 02 78 Amazon ElastiCache User Guide Which Metrics Should Monitor Metric Description Unit StringBasedCmds The total number of commands that are string Count based This is derived from the Redis command stats statistic by summing all of the commands that act upon one or more strings HashBasedCmds The total number of commands that are hash Count based This is derived from the Redis command stats statistic by summing all of the commands that act upon one or more hashes ListBasedCmds The total number of commands that are list based Count This is derived from the Redis commandstats stat istic by summing all of the commands that act upon one or more lists SetBasedCmds The total number of commands that are set based Count This is derived from the Redis commandstats stat istic by summing all of the commands that act upon one or more sets SortedSetBasedCmds The total number of commands that are sorted set Count based This is derived from the Redis command stats statistic by summing all of the commands that act upon one or more sorted sets Currltems The number of items in the cache This is derived Count from the Redis keyspace statistic summing all of the keys in the entire keyspace Which Metrics Should I Monitor T
123. bility Zone for all your nodes allow ElastiCache to select a single Availability Zone for all your nodes specify the Availability Zones for each node or allow ElastiCache to select an Availability Zone for each node New nodes can be created in different Availability Zones as you add them to an existing Memcached cluster Once a cache node is created its Availability Zone cannot be modified If you want a cluster in a single Availability Zone cluster to have its nodes distributed across multiple Availability Zones ElastiCache can create new nodes in the various Availability Zones You can then delete some or all of the original cache nodes We recommend this approach To migrate Memcached nodes from a single Availability Zone to multiple Availability Zones 1 Modify your cluster by creating new cache nodes in the Availability Zones where you want them In your request do the following Set AZMode CLI az mode to cross az e Set NumCacheNodes CLI num cache nodes to the number of currently active cache nodes plus the number of new cache nodes you want to create e Set NewAvailabilityZones CLI new availability zones to a list of the zones you want the new cache nodes created in To let ElastiCache determine the Availability Zone for each new node don t specify a list Set ApplyImmediately CLI apply immediately to true Note If you are not using auto discovery be sure to update your client application with
124. c is calculated at the cache node level For complete documentation of the Redis info command go to http redis io commands info See Also e Host Level Metrics p 75 Metric Description Unit CurrConnections The number of client connections excluding con Count nections from read replicas Evictions The number of keys that have been evicted due to Count the maxmemory limit Reclaimed The total number of key expiration events Count NewConnections The total number of connections that have been Count accepted by the server during this period BytesUsedForCache The total number of bytes allocated by Redis Bytes CacheHits The number of successful key lookups Count CacheMisses The number of unsuccessful key lookups Count ReplicationLag This metric is only applicable for a cache node Seconds running as a read replica It represents how far behind in seconds the replica is in applying changes from the primary cache cluster These are aggregations of certain kinds of commands derived from info commandstats Metric Description Unit GetTypeCmds The total number of get types of commands This Count is derived from the Redis commandstats statistic by summing all of the get types of commands get mget hget etc SetTypeCmds The total number of set types of commands This Count is derived from the Redis commandstats statistic by summing all of the seftypes of commands set hset etc KeyBasedCmds The total num
125. can also use the ElastiCache command line interface CLI The CLI makes it easy to perform one at a time operations such as starting or stopping your cache cluster You can also invoke ElastiCache CLI commands from a scripting language of your choice letting you automate repeating tasks For more information about the CLI see Setting Up the ElastiCache Command Line Interface p 81 If you want to access ElastiCache from an application you can use one of the AWS software development kits SDKs The SDKs wrap the ElastiCache API calls and insulate your application from the low level details of the ElastiCache API You provide your credentials and the SDK libraries take care of authentication and request signing For more information about using the AWS SDKs see Tools for Amazon Web Services You can also write application code directly against the ElastiCache web service API When using the API you must write the necessary code to construct and authenticate your HTTP requests parse the results from ElastiCache and handle any errors For more information about the API see Using the ElastiCache API p 189 Regions and Endpoints By default the AWS SDKs and console for ElastiCache reference the US West Oregon region As ElastiCache expands availability to new regions new endpoints for these regions are also available to use in your own HTTP requests the AWS SDKs and the console For a current list of supported regions and endpoints s
126. cceceeee cence eect eee ee een eee teen tenet een een een eea een een een enaes 177 Authorizing Network Access to an Amazon EC2 Security Group 0 ceeeeeeeeeeeeeeeeeeeeneees 178 Viewing Cache Cluster and Cache Node Metrics cceceeeeeeeneeeee eee ee a eee een eea een eea een eea een eeaeeaes 180 AWS Management Console cccceeeeeceeceece eee eee eee eee eee ece ese ese esa E A EA i 180 GUI ea cin face tenes Seagate eee eee ebay dete stad E eet weet eee 180 AP Wises tenes sida aeet nace eet natu la S E E dace aoa dow tins en E lass dauet ada aueran eutwehes 181 Viewing ElastiCache Events cccceeeeeeeceeeeeeeeee eee eiee a eee eca ese esa ese EE E Ea E 182 AWS Management Console ccccceeeeeceeceec eee ece eee eee eee ece eee ese esa ese ese eseesaeseeseseeea esis 182 CE seve E vee tis aes Sein eno ec aad ee ee ea ek ee ee 182 API Version 2015 02 02 v Amazon ElastiCache User Guide AP Wi case tectstenaeune tha pete cates uecthtpc ast dnat aacnaauten daar a teag dott meee Anand pth ee pce ates 182 Configuring ElastiCache Clients 0 cc cece e ence eee eee reer nena eaten AEAEE E nunu eeaeea esata 184 Restricted Commands occ ccssce onaveres aaki nea nnee niet eave rea E Sas eE parent nea adeate aes Eaa Senses ote 184 Cache Node Endpoints and Port Numbers cee ee eee eee eee eee e ee etre eee ee een ees 184 AWS Management Console serseri aree eee eee a eee es
127. ch to automatically moving slabs If it is set to 2 ElastiCache aggressively moves slabs whenever there is a cache evic tion This mode is not recommen ded except for testing purposes Enable or disable slab reassign ment If this parameter is set to 1 you can use the slabs reassign command to manually reassign memory The following table shows the Memcached 1 4 5 parameters that ElastiCache supports Name Default Type Modifi able backlog_queue_limit 1024 integer No binding_protocol auto string No cas_disabled 0 false Boolean Yes chunk_size 48 integer Yes Description The backlog queue limit The binding protocol If 1 true check and set CAS operations will be disabled and items stored will consume 8 bytes less than with CAS enabled The minimum amount in bytes of space to allocate for the smallest item s key value and flags in bytes API Version 2015 02 02 45 Amazon ElastiCache User Guide Parameters for Memcached Name Default Type Modifi Description able chunk_size_growth_factor 1 25 float Yes The growth factor that controls the size of each successive mem cached chunk each chunk will be chunk_size_growth_factor times larger than the previous chunk error_on_memory_exhausted 0 false Boolean Yes If 1 true when there is no more memory to store items mem cached will return an error rather than evicting items large_memory_pages 0 false Boolean No If 1
128. changes are applied If you don t specify a preferred maintenance window when you create or modify a cache cluster ElastiCache assigns a 60 minute maintenance window on a randomly selected day of the week The 60 minute maintenance window is selected at random from an 8 hour block of time per region The following table lists the time blocks for each region from which the default maintenance windows are assigned API Version 2015 02 02 63 Amazon ElastiCache User Guide Maintenance Window Region Code Region Name Maintenance Window ap northeast 1 Asia Pacific 13 00 21 00 UTC Tokyo region ap southeast 1 Asia Pacific 14 00 22 00 UTC Singapore re gion ap southeast 2 Asia Pacific 12 00 20 00 UTC Sydney region cn north 1l China Beijing 14 00 22 00 UTC region eu central 1 EU Frankfurt 23 00 07 00 UTC region eu west 1 EU Ireland re 22 00 06 00 UTC gion sa east 1 South America 01 00 09 00 UTC Sao Paulo re gion us east 1 US East N Vir 03 00 11 00 UTC ginia region us gov west 1 AWS GovCloud 06 00 14 00 UTC US region us west 1 US West N 06 00 14 00 UTC California re gion us west 2 US West Ore 06 00 14 00 UTC gon region The maintenance window should fall at the time of lowest usage and thus might need modification from time to time You can specify a time range of up to 24 hours in duration during which any maintenance activities you have requested should occur For
129. child process terminates unexpectedly Redis 2 8 6 Redis 2 8 6 adds several bug fixes and new features including Partial resynchronization psync In a replication group the primary cache node maintains a backlog which is a buffer that holds data that has not yet been sent to the read replicas If a replica is disconnected from the primary node then write requests will continue to accumulate in the primary s backlog When a replica re establishes contact with the primary it can request a psync to obtain only the portion of backlog data that the replica missed while it was disconnected In general a psync is much faster than a full sync so a replica can quickly catch up with the primary You can control the size of the backlog buffer You can also control the time to live attribute of the backlog If the replica is unavailable for an extended period of time exceeding the backlog time to live then the backlog is discarded and the replica must perform a full sync when it reconnects Primary node only allows write operations if there are enough available replicas In normal circumstances each read replica pings the primary once every second By default if the primary does not receive a ping from a replica then it will still continue accepting write operations from clients However this can lead to write operation loss as data cannot be sent to the replicas You can now change this behavior so that the primary can stop accepting write oper
130. ciate PONS o API Version 2015 02 02 168 Amazon ElastiCache User Guide Connecting to a Cache Cluster Running in an Amazon VPC Associate Address Cancel x Select the instance or network interface to which you wish to associate this IP address 54 207 55 251 Instance i clalfed3 my ec2 instance 10 0 0 246 Private IP address denotes the primary private IP address or Network Interface Select a network interface Private IP address denotes the primary private IP address Allow Reassociation Cancel Yes Associate You can now use SSH to connect to the Amazon EC2 instance using the Elastic IP address that you created Tip For instructions about using SSH to connect to a Linux UNIX instance go to Connect to Your Linux UNIX Instance in the Amazon EC2 Getting Started Guide To connect to your Amazon EC2 instance 1 Open a command window At the command prompt issue the following command Replace mykeypair pem with the name of your key pair file and replace 54 207 55 251 with your Elastic IP address ssh i mykeypair pem ec2 user 54 207 55 251 2 Do not log out of your Amazon EC2 instance yet You are now ready to interact with your ElastiCache cluster Before you can do that you will need to install the te net utility if you haven t already done so To install telnet and interact with your cache cluster 1 Open a command window At the command prompt issue
131. cluster running the Redis cache engine you can define that cluster as the primary node in a replication group The API call createReplicat ionGroup creates a new replication group with your Redis cache cluster as the primary To add read replicas use the CreateCacheCluster API call to create additional single node cache clusters running in your new replication group From that point on the read replicas will remain synchronized with the primary your applications can perform read only operations on the replicas and read write operations on the primary See Managing Replication Groups p 127 for more information on creating and adding Redis cache clusters to a replication group using the CLI or AWS console If you no longer need the replication group you can use DeleteReplicationGroup to delete it This powerful operation removes the cache nodes cache clusters and all of the other resources used by the replication group For more information see Managing Replication Groups p 127 Accessing Amazon ElastiCache The AWS Management Console is the easiest way to manage Amazon ElastiCache The console lets you create cache clusters add and remove cache nodes and perform other administrative tasks without having to write any code The console also provides cache node performance graphs from CloudWatch showing cache engine activity memory and CPU utilization and other metrics For more information go to the AWS Management Console You
132. context of an ElastiCache cache cluster For more information please see Parameter Groups p 43 Topics e Creating a Cache Parameter Group p 155 e Listing Available Cache Parameter Groups p 157 e Viewing Parameter Values for a Cache Parameter Group p 158 e Modifying a Cache Parameter Group p 162 Creating a Cache Parameter Group The following procedures show you how to create a new cache parameter group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Click Cache Parameter Groups in the navigation list on the left side of the window 3 Click the Create Cache Parameter Group button The Create Cache Parameter Group window appears 4 Inthe Cache Parameter Group Family drop down list box choose a family that is compatible with your cache engine For example a cache parameter group with a family of memcached1 4 can only be used on cache clusters running Memcached 5 Type the name of the new cache parameter group in the Cache Parameter Group text box 6 Type a description for the new cache parameter group in the Description text box 7 Click the Yes Create button CLI Use the command elasticache create cache parameter group with the following parameters PROMPT gt elasticache create cache parameter group myCacheParameterGroup fm memecached1l 4 d My new parameter group This command sho
133. ct to a Redis Cluster In the following example you use the redis cli utility to connect to a cluster that is running Redis Note For more information about Redis and available Redis commands go to htip redis io commands To connect to a Redis cluster using redis cli 1 Connect to your Amazon EC2 instance using the connection utility of your choice API Version 2015 02 02 19 Amazon ElastiCache User Guide Step 4 Connect to a Redis Cluster Note For instructions on how to connect to an Amazon EC2 instance go to the Amazon EC2 Getting Started Guide Before you can build redis cli you will need to download and install the GNU Compiler Collection gcc At the command prompt of your Amazon EC2 instance type the following command At the confirmation prompt type y sudo yum install gcc Loaded plugins priorities security update motd upgrade helper Setting up Install Process Resolving Dependencies gt Running transaction check output omitted Total download size 27 M Installed size 53 M Is this ok y N y Downloading Packages 1 11 binutils 2 22 52 0 1 10 36 amzn1 x86_64 rpm 5 2 MB 00 00 2 11 cpp46 4 6 3 2 67 amzn1 x86_64 rpm 4 8 MB 00 00 3 11 gcec 4 6 3 3 10 amznl noarch rpm 2 8 kB 00 00 output omitted Complete Now you will need to download and compile the redis cli utility This utility is included in the Redis software distribution At the command prom
134. d to Redis cache items to help reduce the amount of paging For example suppose you have acache ml small node witha maxmemory of 900MB bytes If you set reserved memory to 200 MB then Redis allows 700MB to be used for cache item storage before applying the eviction policy the 200MB is available for Redis background saves replication and AOF Consider increasing the reserved memory parameter if you are us ing read replicas append only files AOF or other Redis fea tures that consume more memory Note This parameter is specif ic to ElastiCache and is not part of the standard Redis distribution Determines whether a read replica in Redis can have read replicas of its own The maximum execution time in microseconds for commands to be logged by the Redis Slow Log feature API Version 2015 02 02 56 Amazon ElastiCache User Guide Parameters for Redis Name Default Type Modi Description Sa slowlog max len 128 integer Yes The maximum length of the Redis Slow Log tcp keepalive 0 integer Yes If this is set to a nonzero value N node clients are polled every N seconds to ensure that they are still connected With the default setting of 0 no such polling oc curs timeout 0 integer Yes If this is set to a nonzero value N the node closes a connection if the client is idle for N seconds With the default setting of 0 the node does not disconnect idle cli ents zset max ziplist entr
135. dow Impact of New Add and Remove Requests on Pending Requests Scenarios Pending New Re Operation quest Scenario 1 Delete Delete Scenario 2 Delete Create Scenario 3 Create Delete Scenario 4 Create Create Results The new delete request pending or immediate re places the pending delete request The new create request pending or immediate re places the pending delete request The new delete request pending or immediate re places the pending create request The new create request is added to the pending create request Important If the new create request is set to Apply Immediately Yes all create requests are performed immediately If the new create request is set to Apply Immediately No all create requests are pending To determine what operations are pending click the Description tab and check to see how many pending creations or deletions are shown You cannot have both pending creations and pending deletions API Version 2015 02 02 100 Amazon ElastiCache User Guide Adding or Removing Nodes Cache Cluster mycacheciuster econ on Cache Cluster Details Cache Cluster ID mycachectuster Status available Creation Time July 30 2014 9 45 59 AM UTC 7 Cache Node Type cache r3Jarge Engine memcached Engine Version 1 4 14 Availability Zone Multiple Number of Cache Nodes 8 Number of Nodes Pending Creation 2 Nodes Pending Deletion NWA onfiguration Endpoint
136. e Creating the replication group can take a few minutes When it is ready for use its status changes from creating to available If you want your replication group to be Multi AZ enabled a aooo On the Replication Groups screen select the replication group by clicking the box to the left of the replication group s name Click Modify Select the Yes radio button to the right of Multi AZ Click Modify For more information on Multi AZ see Multi AZ with Redis Replication Groups p 32 Add one or more read replicas to the replication group for more information see Adding a Read Replica To a Replication Group p 133 API Version 2015 02 02 131 Amazon ElastiCache User Guide Creating a Redis Replication Group On the ElastiCache console your new replication group is listed in the Replication Groups panel CLI The following code can be used to create a Redis replication group when you already have an active Redis cluster that is not a member of any other replication group To create a replication group use the elasticache create replication group command The following example creates a replication group named my repgroup with a primary cache cluster named my redis primary PROMPT gt elasticache create replication group my repgroup primary cluster id my redis primary description My replication group automatic failover en abled true This command produces output similar to the following
137. e us west 2 0123456789 cluster myCluster tags Key Service Value elasticache Key Region Value us west 2 You can also use the AWS CLI to add tags to a cluster when you create a new cluster by using the command create cache cluster or when you create a new replication group by using the command create replication group Note that you cannot add tags during resource creation with the ElastiCache management console After the cluster or replication group is created you can then use the console to add tags to the resource ElastiCache API You can use the ElastiCache API to add tags to an existing ElastiCache resource by using the AddTagsToResource action The following code uses the ElastiCache API to add the keys Service and Region with the values elasticache and us west 2 respectively to the resource myCluster in the us west 2 region The ResourceName parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt https elasticache us west 2 amazonaws com Action AddTagsToResource amp ResourceName arn aws elasticache us west 2 0123456789 cluster myCluster amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Tags member 1 Key Servic amp Tags member 1 Value elasticache amp Tags member 2 Key Region amp Tags member 2 Value us west 2 amp amp Version 2015 02 02 Timestamp 20150202T192317
138. e a manual snapshot in one of the following ways Create a snapshot of a cluster This is in addition to any automatic snapshots you have enabled on the cluster e Make a copy of an existing snapshot It does not matter whether the source snapshot was created automatically or manually e Take a final snapshot immediately before deleting a cluster or replication group There is a limit in place on the rate of manual snapshot creation During any contiguous 24 hour period you can create no more than 20 manual snapshots per cluster Manual snapshots do not have retention limits and ElastiCache does not automatically delete them Even if you delete a cluster any manual snapshots from that cluster will be retained If you no longer want to keep a manual snapshot you must explicitly delete it yourself For more information see Creating a Manual Snapshot p 146 Performance Impact of Snapshots Snapshots are created using Redis native BGSAVE command The Redis process on the cache node spawns a child process to write all the data from the cache to a Redis RDB file It can take up to ten seconds to spawn the child process and during this time the parent process is unable to accept incoming application requests After the child process is running independently the parent process resumes normal operations The child process exits when the snapshot operation is complete While the snapshot is being written additional cache node memory is us
139. e cache cluster and is ready for use A cache node could not be added because there are not enough available IP addresses One or more cache cluster parameters have been changed The provisioning of a cache cluster is completed and the cache nodes in the cache cluster are ready to use An attempt was made to launch a new cache cluster into a nonexistent virtual private cloud VPC API Version 2015 02 02 193 Amazon ElastiCache User Guide Event Name ElastiCache CacheClusterRestoreFailed ElastiCache CacheClusterSecurityGroupModified ElastiCache CacheNodeReplaceComplete ElastiCache CacheNodesRebooted ElastiCache CustomerPendingSuspension ElastiCache DeleteCacheClusterComplete ElastiCache NodeReplacementCanceled ElastiCache NodeReplacementRescheduled Description ElastiCache was unable to populate the cache cluster with Redis snapshot data This could be due to a nonexistent snapshot file in Amazon S3 or incorrect permissions on that file If you describe the cache cluster the status will be restore failed You will need to delete the cache cluster and start over For more information see Migrating Your Redis Cluster to ElastiCache p 151 One of the following events has occurred The list of cache security groups authorized for the cache cluster has been modified One or more new EC2 security groups have been authorized on any of the cache security groups associated with the cache
140. e cluster status changes to deleted you stop incurring charges for that cluster 1 Signin to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache In the ElastiCache console dashboard click Cache Clusters 3 Inthe list of clusters to select the cluster to delete click the box to the left of the cluster s name When selected the box will have a colored center You can only delete one cluster at a time from the ElastiCache console Selecting multiple clusters disables the Delete button 4 Click the Delete button The status of the cluster will change to deleting While this cluster is deleting you can delete other clusters by repeating steps 1 through 4 Step 2 Launch a Redis Cluster ElastiCache supports replication when you use the Redis engine To monitor the latency between when data is written to a Redis read write primary cluster and when it is propagated to a read only secondary cluster ElastiCache adds to the cluster a special key Elast iCacheMasterReplicationTimestamp which is the current Universal Coordinated Time UTC time Because a Redis cluster might be added to a replication group at a later time this key is included in all Redis clusters even if initially they are not members of a replication group For more information on replication groups see Replication Groups and Read Replicas Redis p 30 To create a Redis cluster do the following
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142. e esa e a a aieia 185 GET era E A Seadegaydeeta i ad teen ate ebay E bette wee elet as pean nies 185 NAN ma EE E AEA dia taal edalact ate aautiea A E E glachh academe van sae E ssa dale shea suuta cueaehs 2 185 Auto DiSCovery 2 42 22 newer ieiieetieidea oedteden r e ett Mates daa dee a e ed aed dediedia caged 186 Connecting to Nodes in a Replication Group cceeeeeeeec eee eee eee eeceeeeeceeceeseseeseeeeseeeeeseeeeenes 186 AWS Management Console ccccceeeeeceeceece eee eee ece eee ece ese ece ese ecaeceeceeseeseseeeeeseeee esis 186 CED AE E E EE A AEE genet ah varttuan do esac EE eh evant acta E 187 AP I E E A EE E es edness ec ede ee dd ed ee eda ee eon eed 187 DNS Names and Underlying IP isimni etie ac zen taeesaes tae desea getandd aoe n aa a Ei 188 Using the ElastiGache API curis rinena ate dete ca et tenes Deen dias ee E EEE E TEE eei 189 Using the Query API icc go2d5 seeatn ass ecanscs roaa a9 Eea TE aaa E ass aa OO EEEa OEE eee aana 189 Query Parameters sorain ea i e e a Dae ee donde de de oaa eee 189 Query Request Authentication 2 ccccceecceeeeeeeeeeeeeeeaeeeeeece a e a a aE Ei 189 Available Libraries iiio tisk eden cee E ed ee eee cee 191 Troubleshooting Applications ccc eee eee e nent teeta een eeaeeaeeaeenes 191 Retrieving Error Sinira eneee eE E EE E E aid ie iM EEE EE EA E EEA EEEE 191 To bleshooting Tips neten nna rd a ace eet ei ee ee 192 Event Notifications and Amazon SNS
143. e policy is attached to specific users or groups and applies the policy permissions to all your ElastiCache resources In the Action portion of the IAM policy for ElastiCache you scope your policy by specifying any or all ElastiCache actions that you want to control access to When writing a policy to control access to ElastiCache actions use elastiCache act ionName to specify which action or actions the policy is controlling for example elastiCache DescribeCacheClusters To control access to multiple actions list the actions in a comma delimited list Each action name in the list must be prefixed with elastiCache for example elastiCache ModifyCacheCluster elastiCache DescribeCacheClusters For a list of all ElastiCache actions go to the Query API Actions in the Amazon ElastiCache API Reference API Version 2015 02 02 201 Amazon ElastiCache User Guide Example Action Patterns Example Action Patterns Following are some examples that show patterns you can use to specify actions in an IAM policy To control access to a single specific ElastiCache action specify the ElastiCache action name Action elastiCache CreateCacheCluster e To control access to two or more ElastiCache actions specify each action name individually ina comma delimited list within brackets Note that each action in the list is prefaced with elastiCache Action elastiCache CreateCacheCluster elastiCache Cr
144. e rates go to hitp aws amazon com elasticache The details in creating an ElastiCache cluster differ depending upon the engine and some options you choose In general the steps are as follows 1 Select the engine Redis or Memcached 2 Specify cluster details on the Cluster Details page 3 Specify advanced settings on the Configure Advanced Settings page 4 Review your selections and launch 5 Optional Delete your cluster Topics Step 2 Launch a Memcached Cluster p 9 Step 2 Launch a Redis Cluster p 12 Step 2 Launch a Memcached Cluster When you use the Memcached engine Amazon ElastiCache supports horizontally partitioning your data over multiple nodes Memcached enables auto discovery so you don t need to keep track of the endpoints for each node Memcached tracks each node s endpoint updating the endpoint list as nodes are added and removed All your application needs to interact with the cluster is the configuration endpoint For more information on auto discovery see Node Auto Discovery Memcached p 116 To create a new Memcached cluster do the following Prerequisites 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard Step 1 Select the Memcached Engine Before you proceed be sure you have completed the Pre
145. e the same command to make other modifications to a replication group PROMPT gt elasticache modify replication group my repgroup automatic failover enabled true API The following API call modifies an existing Redis replication group to enable Multi AZ You can use the same API call to make other modifications to a replication group https elasticache us west 2 amazonaws com Action ModifyReplicationGroup amp AutomaticFailoverEnabled tru amp ReplicationGroupId my repgroup amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp Version 2014 12 01 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Deleting a Read Replica You can add and delete read replicas however you cannot delete the primary cluster in a replication group To delete a cluster As soon as the cluster status changes to deleted you stop incurring charges for that cluster 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 Inthe ElastiCache console dashboard click Cache Clusters 3 Inthe list of clusters to select the cluster to delete click the box to the left of the cluster s name When selected the box will
146. e639 10 0 1 0 24 Remove Add Cancel Yes Create ao 5 In the Name box type a name for your cache subnet group In the Description box type a description for your cache subnet group In the VPC ID box click the Amazon VPC that you created In the Availability Zone and Subnet ID lists click the Availability Zone and ID of your private subnet and then click Add In the confirmation message that appears click Close API Version 2015 02 02 166 Amazon ElastiCache User Guide Creating a Cache Cluster in an Amazon VPC Your new cache subnet group appears in the Cache Subnet Groups list of the ElastiCache console You can click on the subnet group to see details such as all of the subnets associated with this group at the bottom of the window Now that you ve created a cache subnet group you can launch a cache cluster to run in your Amazon VPC Continue to the next topic Creating a Cache Cluster in an Amazon VPC p 167 Creating a Cache Cluster in an Amazon VPC In this example you will create a cache cluster in your Amazon VPC AWS Management Console To launch a Redis cache cluster see Step 2 Launch a Redis Cluster p 12 On the Step 4 Configure Advanced Settings screen select a VPC subnet group To launch a Memcached cache cluster see Step 2 Launch a Memcached Cluster p 9 On the Step 4 Configure Advanced Settings screen select a VPC subnet group You have now launched a cache cluster inside an Ama
147. eNodeTypeSpecificValues gt lt AllowedValues gt 1 100000 lt AllowedValues gt lt ParameterName gt max_cache_memory lt ParameterName gt lt MinimumEngineVersion gt 1 4 5 lt MinimumEngineVersion gt lt CacheNodeTypeSpecificParameter gt lt CacheNodeTypeSpecificParameter gt API Version 2015 02 02 160 Amazon ElastiCache User Guide Viewing Parameter Values for a Cache Parameter Group lt DataType gt integer lt DataType gt lt Source gt system lt Source gt lt IsModifiable gt false lt IsModifiable gt lt Description gt The number of memcached threads to use lt Description gt lt CacheNodeTypeSpecificValues gt lt CacheNodeTypeSpecificValue gt lt Value gt 2 lt Value gt lt CacheClusterClass gt cache cl medium lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt lt CacheNodeTypeSpecificValue gt lt Value gt 8 lt Value gt lt CacheClusterClass gt cache cl xlarge lt CacheClusterClass gt lt CacheNodeTypeSpecificValue gt output omitted lt CacheNodeTypeSpecificValues gt lt AllowedValues gt 1 8 lt AllowedValues gt lt ParameterName gt num_threads lt ParameterName gt lt MinimumEngineVersion gt 1 4 5 lt MinimumEngineVersion gt lt CacheNodeTypeSpecificParameter gt lt CacheClusterClassSpecificParameters gt lt Parameters gt lt Parameter gt lt ParameterValue gt 1024 lt ParameterValue gt lt DataType gt integer lt DataType gt lt Source gt system
148. eady for use Note As soon as your cluster becomes available you re billed for each hour or partial hour that the cluster is active even if you re not using it To delete the entire replication group see Deleting a Replication Group p 137 AWS Management Console To create a replication group using the AWS Management Console The following steps walk you through the process of creating a Redis replication group when you already have an active Redis cluster that is not a member of any other replication group 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache On the Replication Groups page click Create Replication Group On the Create Replication Group page do the following a In the Primary Cluster ID drop down list click the ID of the existing Redis cluster you want to be the primary cluster in this replication group The cluster you select cannot be a member of any existing replication group In the Replication Group ID box type a name for the replication group Replication group name constraints are as follows A name must contain from 1 to 16 alphanumeric characters or hyphens e The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens In the Replication Group Description box type a meaningful description for the replication group When all the settings are as you want them click Creat
149. eateReplicationGroup e To control access to all actions that begin with the same characters use the wildcard as part of the action name This example is for all ElastiCache actions that begin with Create such as CreateCacheCluster CreateReplicationGroup CreateSnapshot and so on Action elastiCache Create To control access to all ElastiCache actions use the wildcard as the action name Action elastiCache To control access to a group of actions and specific actions you can mix wild carded actions with specific actions in a comma delimited list enclosed in braces Action elastiCache Create elastiCache Delete elastiCache RemoveTagsFromResource elastiCache Describe For example IAM policies for ElastiCache go to the section Example Policies for ElastiCache p 203 below ElastiCache Keys ElastiCache implements the following policy keys but no others For more information about policy keys go to Condition in the in the IAM User Guide documentation AWS Wide Policy Keys aws CurrentTime Io check for date time conditions API Version 2015 02 02 202 Amazon ElastiCache User Guide Example Policies for ElastiCache e aws EpochTime To check for date time conditions using a date in epoch or UNIX time e aws principaltype To check the type of principal user account federated user etc for the current request
150. ecific parameter reserved memory toa value that is at least half of the cluster s maxmemory parameter value Because you cannot modify the reserved memory parameter in the default parameter group you must create a custom parameter group for the cluster The default value for reserved memory is zero 0 which allows Redis to consume all the memory with data potentially leaving no memory for other uses such as BGSAVE For information on creating and modifying parameter groups see Creating a Cache Parameter Group p 155 and Modifying a Cache Parameter Group p 162 API Version 2015 02 02 23 Amazon ElastiCache User Guide Fault Tolerance AOF or Multi AZ For more information on Redis specific parameters in ElastiCache see Parameters for Redis p 48 For more information on creating and modifying parameter groups see Creating a Cache Parameter Group p 155 and Modifying a Cache Parameter Group p 162 Fault Tolerance AOF or Multi AZ When AOF is enabled for Redis every write operation received by the server is logged AOFs can thus become very large larger than the rdb file for the dataset in question Because ElastiCache relies on local storage the instance store which is limited in size enabling AOF can cause out of disk space issues Enabling Redis AOF for Fault Tolerance You enable AOF because an AOF file is useful in recovery scenarios In case of a node restart or service crash Redis will replay the upda
151. ectively insulated from changes to cache node membership ElastiCache has multiple features to enhance reliability for critical production deployments such as automatic detection of and recovery from cache node failures ElastiCache also works together with other Amazon Web Services such as Amazon EC2 CloudWatch and Amazon SNS to provide a secure high performance and managed in memory caching solution Topics Amazon ElastiCache Videos p 2 Are You a First Time ElastiCache User p 3 Data Model p 4 Supported Operations p 5 Accessing Amazon ElastiCache p 6 Supported Regions p 6 API Version 2015 02 02 1 Amazon ElastiCache User Guide Amazon ElastiCache Videos Amazon ElastiCache Videos This section contains videos to help you learn basic and advanced Amazon ElastiCache concepts For information about AWS Training visit AWS Training amp Certification Topics e Introductory Videos p 2 e Advanced Videos p 2 Introductory Videos For introductory videos about Amazon ElastiCache see the following Topics Introduction to Amazon ElastiCache p 2 e DAT207 Accelerating Application Performance with Amazon ElastiCache AWS re Invent 2013 p 2 Introduction to Amazon ElastiCache In this video learn about key Amazon ElastiCache concepts See a demo of creating and launching an Amazon ElastiCache cluster in the Amazon cloud and then go practice with a free lab at Qwik Labs Introductio
152. ed BytesWrittenOutFromMem cached CasBadval CasHits CasMisses CmdFlush CmdGet CmdSet CurrConnections Currltems DecrHits DecrMisses DeleteHits DeleteMisses Evictions GetHits GetMisses IncrHits IncrMisses Description The number of bytes used to store cache items The number of bytes that have been read from the network by the cache node The number of bytes that have been written to the network by the cache node The number of CAS check and set requests the cache has received where the Cas value did not match the Cas value stored The number of Cas requests the cache has re ceived where the requested key was found and the Cas value matched The number of Cas requests the cache has re ceived where the key requested was not found The number of flush commands the cache has re ceived The number of get commands the cache has re ceived The number of set commands the cache has re ceived A count of the number of connections connected to the cache at an instant in time A count of the number of items currently stored in the cache The number of decrement requests the cache has received where the requested key was found The number of decrement requests the cache has received where the requested key was not found The number of delete requests the cache has re ceived where the requested key was found The number of delete requests the cache has re ceived where t
153. ed for new writes If this additional memory usage exceeds the available memory on the node processing can become slow due to excessive paging The following are guidelines for improving snapshotting performance Set the reserved memory parameter To mitigate excessive paging we recommend that you set the reserved memory parameter This parameter prevents Redis from consuming all of the available memory on the node and can help reduce the amount of paging You might also see performance improvements by simply using a larger node For more information about the reserved memory parameter and node memory sizes see Parameters for Redis p 48 Create snapshots on a read replica If you are running Redis in a node group with more than one node you can take a snapshot from the primary node or one of the read replicas Because of the system resources required during a BGSAVE we recommend that you create snapshots on one of the read replicas rather than the primary While the snapshot is being created on the replica the primary node remains unaffected by BGSAVE resource requirements and can continue serving requests without slowing down If you delete a replication group and request a final snapshot ElastiCache will always take the snapshot at the primary node This ensures that you capture the very latest Redis data before the replication group is deleted Restoring From a Snapshot You can restore the data from a snapshot into a new c
154. ed with your resources Use cost allocation tags to organize your AWS bill to reflect your own cost structure To do this sign up to get your AWS account bill with tag key values included Then to see the cost of combined resources organize your billing information according to resources with the same tag key values For example you can tag several resources with a specific application name and then organize your billing information to see the total cost of that application across several services You can also combine tags to track costs at a greater level of detail For example to track your service costs by region you might use the tag keys Service and Region On one resource you might have the values ElastiCache and Asia Pacific Singapore and on another resource the values ElastiCache and EU Frankfurt Youcan then see your total ElastiCache costs but also see them broken out by region For more information go to Use Cost Allocation Tags in the AWS Billing and Cost Management User Guide You can add ElastiCache cost allocation tags to clusters and snapshots When you adad list modify copy or remove a tag the action is applied only to the specified cluster or snapshot even if it is a cluster in a replication group Tags added to snapshots are not used for cost allocation reports Tags on snapshots are used to retain or restore tags on clusters When you create a snapshot the tags on the cluster are copied to the snapsh
155. ediately the operation has pending status until it is performed at your next maintenance window You can cancel any pending operation To cancel a pending operation 1 2 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache In the left navigation pane click Cache Clusters In the Cache Clusters list locate the Nodes column and click the number of nodes link of the cluster for which you want to cancel pending operations Filter All Cache Clusters v Q Xx Clusters a Cache Cluster Engine Nodes Node Type codts Status b G mycacheduster memea NE 5 noses gt he r aro xeailadle The detail panel appears To determine what operations are pending click the Description tab and check to see how many pending creations or deletions are shown You cannot have both pending creations and pending deletions API Version 2015 02 02 103 Amazon ElastiCache User Guide Modifying a Cluster Cache Cluster mycacheciuster Cache Cluster Details Cache Ciuster ID Status Creation Time Cache Node Type Engine Engine Version Availability Zone mycachecluster available July 30 2014 9 45 59 AM UTC 7 cache r3arge memcached 14 14 Mulupie Cache Cluster mycachecluster Cache Cluster Details Cache Cluster ID Status Creation Time Cache Node Type Engine Engine Version Availability Zone Poescription noses mycachectuster avai
156. ee Regions and Endpoints Supported Regions Amazon ElastiCache is available in multiple regions so that you launch ElastiCache clusters in locations that meet your requirements such as launching in the region closest to your customers or to meet certain legal requirements API Version 2015 02 02 6 Amazon ElastiCache User Guide Supported Regions Each region is designed to be completely isolated from the other regions This achieves the greatest possible fault tolerance Regions where ElastiCache is supported Region Code ap northeast l ap southeast 1l ap southeast 2 cn north 1 eu central 1 eu west 1 us gov west 1 sa east 1 us east l us west l us west 2 Region Name Asia Pacific Tokyo region Asia Pacific Singapore region Asia Pacific Sydney region China Beijing region EU Frankfurt region EU Ireland region AWS GovCloud US region For information on using AWS GovCloud US with ElastiCache see Services in the AWS GovCloud US region ElastiCache South America Sao Paulo US East N Virginia US West N California US West Oregon For a table of AWS products and services by region see Products and Services by Region API Version 2015 02 02 7 Amazon ElastiCache User Guide Step 1 Before You Begin Getting Started with Amazon ElastiCache Topics Step 1 Before You Begin p 8 Step 2 Launch a Cluster p 8 Step 3 Authorize Access p 15 Step 4 Connec
157. ee ee eeeeeneeeeeaeeaeeaeeaeeaes 32 Multi AZ with Redis Replication Groups cecceeceee eee e renee eee e eee ee ee ee etree eset a een ee een een een einige 32 Notes on Multi AZ with Redis Replication Groups ccceeeeeeeeeeeeeeeeeeeaeeeeeaeeeeeaeeneeaeees 32 Failure Scenarios and Multi AZ RESPONSES ccceeeee eee ee eee eeceee een eeeeeaeeeeeaeeeeeaeeeeeaeeaeed 33 Enabling Redis Mullti AZ ccc cccecec eee ne eee e eee tenes eee a esate nese een eea een iS aani aiii 35 API Version 2015 02 02 iii Amazon ElastiCache User Guide Backup and Restore for Redis Clusters ceceeee eee e ee ener etre etre eter rene een eea eed 38 Constraints ict ccseisiceis aceite cst Hae ea aes es a ed sce ea 39 GOSIS AE Ro aai aa SE AN aE E RETER teak rade tens eE OA EE ATE RE TERA kaS SEE EE A RENE REE A SN 39 Automatic Snapshots nsss sneri rinine n ani a aa A aE E a iaa a 39 Manual SnapShots oeie a ea aa a eed e a a a a a aa O A SOA a 39 Performance Impact of Snapshots ccceeeeeee eee eee teen ee eee eee esse eseeseeseeseeseeseeseeeeeseeeees 40 Restoring From a Snapshot iresi eseri neraso ans See ige aa an eaaa a ed castes OVSA TEER a 40 Deleting Snapshots ss miroase iee aeei eae oh ev ech vee E E E E eed ve E EEI 41 CIUSTONS act ce E A E E E E E E E AE EA 41 Memcached Clusters sneri neii iiet ek we EET E EOE EEEE EENE EE EA 41 Redis Clusters inei se nni Ea kut AEEA E SEE ane vente pa ga
158. eeeeeeceeeeeeeeceeeeeseeeeeeeeeeeeeeeeeeeees 24 Enabling Redis Multi AZ as a Better Approach to Fault Tolerance ceeeeeeneeeeeeeeeeeneees 24 Configuring Your ElastiCache Client for Efficient Load Balancing ccecceceeeeeeeeeceeeeeeeeeees 24 Consistent Hashing USING Java 0 cece eee ee eee eee eee eee ee etre rere eee e arene neta eea eee eenetaeegs 25 Consistent Hashing Using PHP cccececeeeee eee e eee eee tere een rere eee e neta eta eea een eeaeeaeeaeeae 25 Consistent Hashing Using NET ccceeeeeeee cece ee eee ee eee ee eee eee eee eeeeseeeeeseeseeseeseeeeeseeeeees 25 ElastiCache Terminology and Concepts ecceeeeee eect teeter eee eee nee ee een ee ee eee renee een ee een eee nenene ennn 26 US or tenant a ne fo a a ee ee 26 Node Considerations for Memcached ceeeeeeee eee eee ener reer e renee reer rere nent 27 Node Considerations for Redis 00 ceceeenee eee eec een eee een eee nea eeeedeeeeeaeeseeaeeeeeaeeseeaeeaeeaeees 29 Reserved NOGES eiiean aa apie a aaea a i a ia Eaa a aaa OREN 29 Replication Groups and Read Replicas Redis cceeeeeeneeeeeeeeeeeceeeeeaeeeeeaeeeeeaeeaeeaeeaeeaeeaes 30 Pomar ENG Ua mereen ae E e a E E E E S 31 Creating a Replication Group 00 ccceeeeeeeee teen cent eee e eee eee e eee eee eee eseeeeese esse eseeeeeseeeeeeeeaes 31 Adding a Redis Cache Cluster to a Replication Group cceeeeeeene
159. eeeeneeeeeeeeeeeaeeeeeaeeaeeaeees 143 Enabling Automatic Snapshots for a Replication Group cceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeenes 144 Creating a Manual Snapshot cccece cece eee eee eee eee renee renee een ee renee een eea een eeaes 146 Displaying a List Of SnapShots areira cece eee eect eee eect eee ece eee ese eee ese iea i e eR E aia 148 Copying a Snapshot rosenie eae etna dee deal ee uae ded ered 148 Restoring a Snapshot to a New Cluster cccceeeeecee eee eee eeaeeeeeaeee een eaeeaeeeeeaeeeeeaeeaeeaes 149 Migrating Your Redis Cluster to ElastiCache ccceeeeeeeee eee eeeeeneeeeeaeeseeaeeneeaeeeeeaeeaeeaes 151 Deleting Snapshots aenema irern see een ee caa saw naa Casa aE tea etet ena ren eac ea aE EEA 153 Managing Cache Parameter Group cceeeee cece ee cece een ee cee aeeeeeaeeeeedeeseedeeseeaeeseeaeeaeeaeeaeeaeees 155 Creating a Cache Parameter Group cccceeeeee eee ee eee reeset een eee eed eea eed eea een eea een eeaeeneeas 155 Listing Available Cache Parameter Grou 0 cceeeeeneeeeee eee een eee eeaeeeeeaeeeeeaeeaeeneeaeeaeees 157 Viewing Parameter Values for a Cache Parameter Group ecceeeeeeeeeeeeeeee eee eee een eeeeenees 158 Modifying a Cache Parameter Group ccceeeeee teen eee e eee eee ee ee ee a eee een eea een eea eset een eeaeeae 162 Using ElastiCache with Amazon Virtual Private Cloud VPC eseeeeeeeneeeeea eee een ee
160. efault active PARAMGRP default memcached1l 4 in sync For more information on elasticache modify cache cluster see http docs aws amazon com AmazonElastiCache latest CommandLineReference CLIReference cmd ModifyCacheCluster html API To modify a cluster call the ModifyCacheCluster action Example The following code sets the number of days a snapshot is retained before deleting SnapshotRetentionLimit ON my cache cluster to 8 https elasticache us west 2 amazonaws com Action ModifyCacheCluster amp CacheClusterId my cache cluster amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp SnapshotRetentionLimit 8 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt For more information on Modi fyCacheCluster see http docs aws amazon com AmazonElastiCache latest APIReference API_ModifyCacheCluster html API Version 2015 02 02 105 Amazon ElastiCache User Guide Managing Reserved Nodes Managing Reserved Nodes Reserved nodes let you make a one time up front payment for a cluster reserve the cluster for a one or three year term and pay a significantly lower rate for each hour you run that cluster Reserved nodes are available in three varieties Heavy Utilizat
161. elect a time range e When the settings are as you want them click Modify CLI To enable automatic snapshots on read replica in a replication group use the elasticache modify replication group command The following example enables automatic snapshots by setting snapshotting cluster id to a read replica cluster name and by setting snapshot retention limit to a nonzero value in this example the retention period is 2 days PROMPT gt elasticache modify replication group replication group id my regroup snapshotting cluster id my replica 1 snapshot retention limit 2 API To enable automatic snapshots for a read replica in a replication group use the ModifyReplicationGroup action with the following parameters ReplicationGroupId e SnapshottingClusterId SnapshotRetentionLimit must be set to a nonzero value to enable automatic snapshots The following example enables automatic snapshots by setting snapshotting cluster id to a read replica cluster name and by setting snapshot retention limit to a nonzero value in this example the retention period is 2 days API Version 2015 02 02 145 Amazon ElastiCache User Guide Creating a Manual Snapshot Example https elasticache us west 2 amazonaws com Action ModifyReplicationGroup amp ApplyImmediately fals amp SnapshotRetentionLimit 2 amp SnapshottingClusterId my replica 1 amp ReplicationGroupId myreplgroup amp Version 2014 12 01
162. emoving nodes you will need to update the list of nodes in the client code Adding Auto Discovery To Your Client Library The configuration information for Auto Discovery is stored redundantly in each cache cluster node Client applications can query any cache node and obtain the configuration information for all of the nodes in the cluster The way in which an application does this depends upon the cache engine version If the cache engine version is 1 4 14 or higher use the config command If the cache engine version is lower than 1 4 14 use the get AmazonElastiCache cluster command The outputs from these two commands are identical and are described in the Output Format p 124 section below API Version 2015 02 02 123 Amazon ElastiCache User Guide Node Auto Discovery Memcached Cache Engine Version 1 4 14 or Higher For cache engine version 1 4 14 or higher use the config command This command has been added to the Memcached ASCII and binary protocols by ElastiCache and is implemented in the ElastiCache Cluster Client If you want to use Auto Discovery with another client library then that library will need to be extended to support the config command Note The following documentation pertains to the ASCII protocol however the config command supports both ASCII and binary If you want to add Auto Discovery support using the binary protocol refer to the source code for the ElastiCache Cluster Client
163. ent hashing Spee ve O he application issues a get request for a particular data item identified by its key API Version 2015 02 02 122 Amazon ElastiCache User Guide Node Auto Discovery Memcached he client uses a hashing algorithm against the key to determine which cache node contains the data item Qo he data item is requested from the appropriate node e data item is returned to the application Connecting to Cache Nodes Manually If your client program does not use Auto Discovery it can manually connect to each of the cache nodes This is the default behavior for Memcached clients You can obtain a list of cache node hostnames and port numbers from the AWS Management Console You can also use the elasticache describe cache clusters command with the show cache node info parameter Example The following Java code snippet shows how to connect to all of the nodes in a four node cache cluster ArrayList lt String gt cacheNodes new ArrayList lt String gt Arrays asList mycachecluster fnjyzo 0001 usel cache amazonaws com 11211 mycachecluster fnjyzo 0002 usel cache amazonaws com 11211 mycachecluster fnjyzo 0003 usel cache amazonaws com 11211 mycachecluster fnjyzo 0004 usel cache amazonaws com 11211 MemcachedClient cache new MemcachedClient AddrUtil getAddresses cacheNodes Important If you scale up or scale down your cache cluster by adding or r
164. er Parameter groups control the run time parameters of your cluster For more information on parameter groups see Parameters for Memcached p 44 In the Configuration section of the Specify Cluster Details page specify settings as shown following a Cluster Name Type a meaningful name for this cluster Cluster name constraints are as follows A name must contain from 1 to 20 alphanumeric characters or hyphens e The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens Node Type From the list select the node type you want to use for this cluster For information on node types see Parameters for Memcached p 44 Number of Nodes Type in the number of nodes you want launched for this cluster For Memcached you may have from 1 to 20 nodes in a cluster If you want to use the Memcached Flexible Zone Placement functionality type a value between 2 and 20 You incur a charge for each node Click Next Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details API Version 2015 02 02 90 Amazon ElastiCache User Guide Creating a Cluster To configure your cluster s advanced settings 1 Inthe Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this cluster associated
165. erag amp Dimensions member 1 CacheClusterId mycachecluster amp Dimensions member 2 CacheNodelId 0002 amp Namespace AWS ElastiCache amp MeasureName CPUUtilization amp Timestamp 2013 07 07T17 3A48 3A21 7462Z amp AWSAccessKeyId lt AWS Access Key ID gt amp Signature lt Signature gt API Version 2015 02 02 181 Amazon ElastiCache User Guide Viewing ElastiCache Events Viewing ElastiCache Events ElastiCache logs events that relate to your cache instances cache security groups and cache parameter groups This information includes the date and time of the event the source name and source type of the event and a description of the event You can easily retrieve events from the log using the elasticache describ vents command or the DescribeEvents API The following procedures show you how to view all ElastiCache events for the past 24 hours specified in seconds AWS Management Console To view all ElastiCache instance events for the past 24 hours 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Click Cache Events in the navigation list on the left side of the window The available events appear in the Cache Events list Note You can use the Viewing drop down list box to filter the events by type CLI To view all ElastiCache instance events for the past 24 hours e Use the command elasticache describe event
166. ermissions to take effect CLI Use the command elasticache authorize cache security group ingress to grant access to an Amazon EC2 security group PROMPT gt elasticache authorize cache security group ingress default ec2 secur ity group name myec2group c2 security group owner id 987654321021 API Version 2015 02 02 178 Amazon ElastiCache User Guide Authorizing Network Access to an Amazon EC2 Security Group The command should produce output similar to the following SECGROUP Name Description SECGROUP default default EC2 SECGROUP myec2group 987654321021 authorizing API Call AuthorizeCacheSecurityGroupIngress with the following parameters EC2SecurityGroupName myec2group EC2SecurityGroupOwnerId 987654321021 Example https elasticache us west 2 amazonaws com Action AuthorizeCacheSecurityGroupIngress amp EC2SecurityGroupOwnerlId 987654321021 amp EC2SecurityGroupName myec2group amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 179 Amazon ElastiCache User Guide Viewing Cache Cluster and Cache Node Metrics Vi
167. ers numCacheNodes 2 cacheClusterId test memcached engine memcached aZMode cross az cacheNodeType cache ml small Fz responseElements engine memcached clientDownloadLandingPage https console aws amazon com elastic ache home client download cacheParameterGroup cacheParameterGroupName default memcached1 4 cacheNodeldsToReboot Fa parameterApplyStatus in sync Faz preferredAvailabilityZone Multiple numCacheNodes 2 cacheNodeType cache ml small cacheClusterStatus creating autoMinorVersionUpgrade true preferredMaintenanceWindow thu 05 00 thu 06 00 cacheClusterId test memcached engineVersion 1 4 14 cacheSecurityGroups API Version 2015 02 02 197 Amazon ElastiCache User Guide Understanding ElastiCache Log File Entries Status active cacheSecurityGroupName default le pendingModifiedValues requestID 104 30b3 3548 11e4 b7b8 6d7 9ffe84edda eventID 92762127 7a68 42ce 8787 927d2174cdel The following example shows a CloudTrail log entry that records a DescribeCacheCluster action Note that for all ElastiCache Describe calls Describe the ResponseElements section is removed and appears as null eventVersion 1 01 userIdentity type IAMUser orincipallId EXAMPLEEXAMPLEEXAMPLE arn arn awS iam 123456
168. ersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Viewing a Cache Security Group You can view detailed information about your cache security group The following procedures show you how to view the properties of a cache security group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Security Groups The available cache security groups appear in the Cache Security Groups list 3 Select a cache security group from the Cache Security Groups list The list of authorizations defined for the cache security group appears in the detail section at the bottom of the window CLI Use the elasticache describe cache security groups to view a cache security group PROMPT gt elasticache describe cache security groups mycachesecuritygroup API Call DescribeCacheSecurityGroups with the following parameter CacheSecurityGroupName mycachesecuritygroup API Version 2015 02 02 177 Amazon ElastiCache User Guide Authorizing Network Access to an Amazon EC2 Security Group Example https elasticache
169. ewing Cache Cluster and Cache Node Metrics ElastiCache and CloudWatch are integrated so you can gather a variety of metrics You can monitor these metrics using CloudWatch Note The following examples require the CloudWatch command line tools For more information about CloudWatch and to download the developer tools go to the CloudWaitch product page The following procedures show you how to use CloudWatch to gather storage space statistics for an cache cluster for the past hour Note The Start Time and EndTime values supplied in the examples below are for illustrative purposes You must substitute appropriate start and end time values for your cache nodes AWS Management Console To gather CPU utilization statistics for a cache cluster 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Select the cache nodes you want to view metrics for a Onthe Cache Clusters page of the AWS Management Console click the name of one or more cache clusters The detail page for the cache cluster appears Click the Nodes tab at the top of the window c Onthe Nodes tab of the detail window select the cache nodes that you want to view metrics for A list of available CloudWatch Metrics appears at the bottom of the console window d Click on the CPU Utilization metric The CloudWatch console will open displaying your selected metrics You can use the Statistic and Pe
170. example if you enable ElastiCache to automatically upgrade your cluster at minor version changes noncritical Memcached or Redis software updates are applied during this time Such updates occur infrequently generally once every few months and will be announced on the Amazon ElastiCache forum two weeks prior to being applied Any deferred or pending cluster modifications you have requested also occur during this time For more information about how to adjust the preferred maintenance window for your cache clusters see Modifying a Cluster p 104 API Version 2015 02 02 64 Amazon ElastiCache User Guide Using Cost Allocation Tags in ElastiCache When you add cost allocation tags to your resources in Amazon ElastiCache you can track costs by grouping expenses on your invoices by resource tag values An ElastiCache cost allocation tag is a key value pair that you define and associate with an ElastiCache resource The key and value are case sensitive A tag key can be used to define a category and the tag value can be an item in that category For example you might define a tag key of CostCenter anda tag value of 10010 indicating that the resource is assigned to the 10010 cost center You can also use tags to designate resources as being used for test or production by using a key such as Environment and values such as test or production We recommend that you use a consistent set of tag keys to make it easier to track costs associat
171. ey store You want to replicate your data from the primary to one or more read replicas for availability You need automatic failover if any of your primary nodes fail You want publish and subscribe pub sub capabilities the client being informed of events on the server You want backup and restore capabilities Once you select the engine for your application we recommend that you use the most recent version of that engine The following sections highlight major differences between the various versions Memcached Versions ElastiCache supports two versions of Memcached 1 4 14 and 1 4 5 Topics Memcached Version 1 4 14 p 87 Memcached Version 1 4 5 p 88 Memcached Version 1 4 14 Memcached improvements added since version 1 4 5 include the following Enhanced slab rebalancing capability e Performance and scalability improvement e Introduced the touch command to update the expiration time of an existing item without fetching it e Auto discovery the ability for client programs to automatically determine all of the cache nodes ina cluster and to initiate and maintain connections to all of these nodes API Version 2015 02 02 87 Amazon ElastiCache User Guide Redis Versions Memcached Version 1 4 5 Memcached version 1 4 5 was the initial engine and version supported by Amazon ElastiCache Redis Versions ElastiCache supports three versions of Redis 2 8 19 2 8 6 and 2 6 13 Topics Redis Ve
172. f ElastiCache you cannot use the ElastiCache console or API or AWS CLI to create an external rdb snapshot For information on using Redis commands go to the Redis Documentation To manually create a snapshot you can access directly 1 Create an EC2 instance Go to Amazon Elastic Compute Cloud Documentation for guidance 2 Install the Redis engine on this EC2 instance 3 Connect this instance as a read replica to the primary node of your ElastiCache replication group API Version 2015 02 02 147 Amazon ElastiCache User Guide Displaying a List of Snapshots We discourage creating external replicas as part of your normal workload because ElastiCache cannot fail over to external replicas 4 Take a snapshot of this external read replica using the asynchronous Redis BGSAVE command Store the rdb file 6 Shut down Redis on your EC2 instance o Displaying a List of Snapshots The following procedures show you how to display a list of your snapshots AWS Management Console To display snapshots using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Snapshots 3 Use the Filter field to display manual automatic or all snapshots CLI To display a list of snapshots use the elast icache describe snapshots command The following example displays a list describing all of the
173. f one or more cache nodes all of which run an instance of supported cache engine software When you create a cache cluster you specify the cache engine that all of the nodes will use Most ElastiCache operations are performed at the cluster level You can set up a cache cluster with a specific number of cache nodes and a cache parameter group that controls the properties for each cache node All cache nodes within a cluster are designed to be of the same node type and have the same parameter and security group settings Every cluster must have a cluster identifier The cluster identifier is a customer supplied name for the cluster This identifier specifies a particular cluster when interacting with the ElastiCache API and commands The cluster identifier must be unique for that customer in an AWS region The following are descriptions of supported cache engine software for ElastiCache Memcached Clusters Memcached is a distributed caching solution that uses using client side hashing to distribute data evenly across one or more cache nodes You can scale up a Memcached cluster by adding more cache nodes For more information go to http memcached org ElastiCache supports the following versions of Memcached Memcached 1 4 14 Memcached 1 4 14 adds several bug fixes and new features including Ability to rebalance and fine tune slab memory Use the slab_automove and slab_reassign parameters to change the way that Memcached manages slab
174. f the nodes in the cluster without any further intervention iy KKK KK KKK KKK KKK KKK Sample C code to show how to integrate with the Amazon ElastiCcache Auto Discovery feature using System using Enyim Caching using Amazon ElastiCacheCluster using Enyim Caching Memcached public class DotNetAutoDiscoveryDemo public static void Main String args instantiate a new client ElastiCacheClusterConfig config new ElastiCacheClusterConfig mcachedClient memClient new MemcachedClient config add data to the cluster memClient Store StoreMode Set 3600 This is the data value end Main end class DotNetAutoDiscoverDemo API Version 2015 02 02 120 Amazon ElastiCache User Guide Node Auto Discovery Memcached How Auto Discovery Works Topics Connecting to Cache Nodes p 121 e Normal Cluster Operations p 122 This section describes how client applications use ElastiCache Cluster Client to manage cache node connections and interact with data items in the cache Connecting to Cache Nodes From the application s point of view connecting to the cluster configuration endpoint is no different than connecting directly to an individual cache node The following sequence diagram shows the process of connecting to cache nodes ElastiCache Cluster ElastiCache Cluster Client Create client using configuration endpoint Resolve configu
175. first determine the node endpoint API Version 2015 02 02 17 Amazon ElastiCache User Guide Step 4 Connect to a Memcached Node To determine the endpoint for a node 1 On the Cache Clusters page of the AWS Management Console click the name of a cluster 2 On the detail page for the cluster click the Nodes tab 3 On the Nodes tab note the endpoint of a node to use in the next step Note The endpoint for your node isn t available until your node is in the available state Cache Cluster mycachecluster Description Nodes Add Node Copy Node Endpoint oOo Nodeld Status Port Endpoint 0001 available 11211 mycachecluster b47jtf 0001 use1 cache amazonaws com Now that you have an endpoint you can log in to an Amazon EC2 instance and connect to the cache node The procedure depends on the engine that you are using Step 4 Connect to a Memcached Node p 18 Step 4 Connect to a Redis Cluster p 19 Step 4 Connect to a Memcached Node In the following example you use the telnet utility to connect to a node that is running Memcached Note For more information about Memcached and available Memcached commands go to http memcached org To connect to a node using telnet 1 Connect to your Amazon EC2 instance by using the connection utility of your choice Note For instructions on how to connect to an Amazon EC2 instance go to the Amazon EC2 Getting Started Guide 2 You will need to download and ins
176. formation on creating and authenticating requests and handling responses Amazon ElastiCache API Reference This is a Separate document with all of the ElastiCache API operations including syntax and examples Data Model The Amazon ElastiCache data model concepts include cache nodes cache clusters security configuration and replication groups The ElastiCache data model also includes resources for event notification and performance monitoring these resources complement the core concepts Cache Nodes Acache node is the smallest building block of an ElastiCache deployment Each node has its own memory storage and processor resources and runs a dedicated instance of cache engine software either Memcached or Redis ElastiCache provides a number of different cache node configurations for you to choose from depending on your needs You can use these cache nodes on an on demand basis or take advantage of reserved cache nodes at significant cost savings Cache Cluster A cache cluster is a collection of one or more cache nodes each of which runs its own instance of supported cache engine software You can launch a new cache cluster with a single ElastiCache operation CreateCacheCluster specifying the number of cache nodes you want and the runtime parameters for the cache engine software on all of the nodes Each node in a cache cluster has the same compute storage and memory specifications and they all run the same cache engine s
177. fying a maintenance window so that downtime for maintenance will have the least impact upon your business b Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see http aws amazon com sns Click Next Step 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings To review your settings and launch your cluster 1 2 Review all your settings to ensure each value is what you want If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launch Replication Group to launch your cluster or replication group To return to the Cache Clusters screen click Close on the Success screen API Version 2015 02 02 11 Amazon ElastiCache User Guide Step 2 Launch a Redis Cluster Your cluster will have the status creating while it is being created When the status changes to available it s ready for use Note As soon as your cluster becomes available you re billed for each hour or partial hour that the cluster is active even if you re not using it Step 5 Delete the Cluster Optional To delete a cluster As soon as th
178. g RESERVATION ReservationId Class Start Time Duration Fixed Pric Usage Pric Count State Description Offering Type RESERVATION ki real ri test5 cache ml small 2013 07 09T23 37 44 720Z ly 455 00 USD 0 092 USD 1 retired memcached Medium Utiliza tion API To get information about reserved nodes for your AWS account call the DescribeReservedCacheNodes action API Version 2015 02 02 106 Amazon ElastiCache User Guide Managing Reserved Nodes Example https elasticache us west 2 amazonaws com Action DescribeReservedCacheNodes amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This call returns output similar to the following lt DescribeReservedCacheNodesResponse xmlns http elasticache us west 2 amazonaws com doc 2013 06 15 gt lt DescribeReservedCacheNodesResult gt lt ReservedCacheNodes gt lt ReservedCacheNode gt lt OfferingType gt Medium Utilization lt OfferingType gt lt CurrencyCode gt USD lt CurrencyCode gt lt RecurringCharges gt lt ProductDescription gt memcached lt ProductDescription gt lt ReservedCacheNodesOf feringId gt 6
179. g Nodes To review your settings and launch your cluster 1 Review all your settings to ensure each value is what you want 2 If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launch Replication Group to create your cluster or replication group 3 To return to the Cache Clusters screen click Close on the Success screen Your cluster will have the status creating while it is being created When the status changes to available it s ready for use Note As soon as your cluster becomes available you re billed for each hour or partial hour that the cluster is active even if you re not using it When you no longer need the cluster you can delete it See Deleting a Cache Cluster p 114 Adding or Removing Nodes By adding or removing nodes you can accommodate changes in your application s capacity requirements Note At this time you can only add or remove nodes from clusters running Memcached Topics Adding Nodes To A Cluster p 96 e Removing Nodes from a Cluster p 99 Canceling Pending Add or Delete Node Operations p 103 The following procedures show you how to add and remove nodes Adding Nodes To A Cluster You can use the AWS Management Console the ElastiCache API or ElastiCache CLI to add nodes to your cluster AWS Management Console To add nodes to a cluster using the AWS Management Console 1 Sign in to the AWS
180. g the ElastiCache Cluster Client for PHP p 206 lt php Sample PHP code to show how to integrate with the Amazon ElastiCcache Auto Discovery feature 7 Configuration endpoint to use to initialize memcached client This is only an example Sserver_endpoint php autodiscovery 1lzvgtq cfg usel cache amazonaws com Port for connecting to the ElastiCache cluster This is only an example Sserver_port 11211 The following will initialize a Memcached client to utilize the Auto Discov ery feature By configuring the client with the Dynamic client mode with single endpoint the client will periodically use the configuration endpoint to retrieve the current cache cluster configuration This allows scaling the cache cluster up or down in number of nodes without requiring any changes to the PHP application ay Sdynamic_client new Memcached Sdynamic_client gt setOption Memcached OPT_CLIENT_MODE Memcached DYNAMIC_CLI ENT_MODE Sdynamic_client gt addServer server_endpoint S server_port j Sdynamic_client gt set key value 60 Store the data for 60 seconds in the cluster the client will decide which node to store Configuring the client with Static client mode disables the usage of Auto Discovery and the client operates as it did before the introduction of Auto Discovery The user can t
181. group then do the promotion and finally re enable Multi AZ ElastiCache Multi AZ and append only file AOF are mutually exclusive If you enable one you cannot enable the other For more information see Fault Tolerance AOF or Multi AZ p 24 In the case where a cluster s failure is caused by the rare event of an entire Availability Zone failing the replica replacing the failed primary is created only when the Availability Zone is back up For example if the primary cluster is in AZ 1 with replicas in AZ 2 and AZ 3 if the primary cluster fails the replica with the least replication lag is promoted to primary ElastiCache then creates a new replica in AZ 1 where the failed primary was only when AZ 1 is back up and available Rebooting a primary cluster does not trigger auto failover When the primary node is rebooted it is cleared of data when it comes back online When the read replicas see the cleared primary they clear their copy of the data incurring data loss Once a read replica has been promoted the other replicas sync with their new primary After the initial sync the replicas content is deleted and they sync the data from the new primary causing a brief interruption during which the replicas are not accessible This sync process also causes temporary API Version 2015 02 02 32 Amazon ElastiCache User Guide Failure Scenarios and Multi AZ Responses load on the primary while syncing with the replicas This beha
182. h Replication Group to launch your cluster or replication group 3 To return to the Cache Clusters screen click Close on the Success screen Your cluster will have the status creating while it is being created When the status changes to available it s ready for use Note As soon as your cluster becomes available you re billed for each hour or partial hour that the cluster is active even if you re not using it When you no longer need the cluster you can delete it See Deleting a Cache Cluster p 114 CLI To create a cluster use the elasticache create cache cluster command The following example creates a Memcached cluster named my cache cluster that has three nodes PROMPT gt elasticache create cache cluster my cache cluster n 3 c cache ml large memcached sg default This command should produce output similar to the following CACHECLUSTER my cache cluster https console aws amazon com elastic ache home client download cache ml larg memcached creating 3 1 4 14 CACHESECURITYGROUP default active CACHEPARAMETERGROUP default memcached1l 4 in sync API To create a cluster use the CreateCacheCluster action The following example creates a single node Redis cluster named my redis primary and seeds it with a snapshot file that has been copied to Amazon S3 API Version 2015 02 02 92 Amazon ElastiCache User Guide Creating a Cluster Examp
183. have a colored center API Version 2015 02 02 136 Amazon ElastiCache User Guide Deleting a Replication Group You can only delete one cluster at a time from the ElastiCache console Selecting multiple clusters disables the Delete button 4 Click the Delete button The status of the cluster will change to deleting While this cluster is deleting you can delete other clusters by repeating steps 1 through 4 Deleting a Replication Group If you no longer need a replication group you can delete it When you delete a replication group ElastiCache deletes all of the clusters in that group including the primary cluster and any read replicas Once you have begun this operation it cannot be interrupted AWS Management Console To delete a replication group 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache In the left navigation pane click Replication Groups In the Replication Groups list click the replication group you want to delete Click Delete In the Delete Replication Group dialog box click Yes Delete ar oN The status of the replication group will change to deleting The deleting process can take several minutes When the replication group is no longer listed it is deleted and you stop incurring changes for it and its clusters CLI Use the command elasticache delete replication group to delete a replication group PRO
184. he Tools The command line tools depend on an environment variable AWS _ELASTICACHE_HOME to locate supporting libraries You need to set this environment variable before you can use the tools Set it to the path of the directory you unzipped the command line tools into This directory is named ElastiCacheCli A B nnnn A B and n are version release numbers and contains subdirectories named bin and lib To set the AWS_ELASTICACHE_HOME environment variable Open a command line window and enter one of the following commands to set the AWS_ELASTICACHE_HOME environment variable On Linux and UNIX enter the following command export AWS_ELASTICACHE_HOME lt path to tools gt On Windows enter the following command C gt set AWS_ELASTICACHE_HOME lt path to tools gt To make the tools easier to use we recommend that you add the tools BIN directory to your system PATH The rest of this guide assumes that the BIN directory is in your system path To add the tools BIN directory to your system path Enter the following commands to add the tools BIN directory to your system PATH e On Linux and UNIX enter the following command export PATH SPATH AWS_ELASTICACHE_HOME bin On Windows enter the following command C gt set PATH PATH3 SAWS_ELASTICACHE HOME bin Note The Windows environment variables are re
185. he box will have a colored center You can only delete one cluster at a time from the ElastiCache console Selecting multiple clusters disables the Delete button Click the Delete button The status of the cluster will change to deleting While this cluster is deleting you can delete other clusters by repeating steps 1 through 4 Congratulations You have successfully launched authorized access to connected to and deleted a cluster Where Do I Go From Here Now that you have tried the getting started exercise you can explore the following sections to learn more about ElastiCache ElastiCache Terminology and Concepts p 26 Setting Up the ElastiCache Command Line Interface p 81 Managing ElastiCache p 86 API Version 2015 02 02 21 Amazon ElastiCache User Guide Ensuring That You Have Sufficient Memory to Create a Redis Snapshot Best Practices for Implementing Amazon ElastiCache This topic identifies best practices for implementing Amazon ElastiCache Topics Ensuring That You Have Sufficient Memory to Create a Redis Snapshot p 22 Fault Tolerance AOF or Multi AZ p 24 Configuring Your ElastiCache Client for Efficient Load Balancing p 24 Ensuring That You Have Sufficient Memory to Create a Redis Snapshot When you work with Redis ElastiCache Redis calls the BESAVE command in a number of cases e When creating a snapshot for a backup restore e When synchronizing a prim
186. he following CloudWatch metrics offer good insight into ElastiCache performance In most cases we recommend that you set CloudWatch alarms for these metrics so that you can take corrective action before performance issues occur CPUUtilization This is a host level metric e Memcached Since Memcached is multi threaded this metric can be as high as 90 If you exceed this threshold scale your cache cluster up by using a larger cache node type or scale out by adding more cache nodes e Redis Since Redis is single threaded the threshold is calculated as 90 number of processor cores For example suppose you are using a cache m1 xlarge node which has four cores In this case the threshold for CPUUtilization would be 90 4 or 22 5 You will need to determine your own threshold based on the number of cores in the cache node that you are using If you exceed this threshold and your main workload is from read requests scale your cache cluster out by adding read replicas If the main workload is from write requests we recommend scaling up by using a larger cache instance type SwapUsage This is a host level metric API Version 2015 02 02 79 Amazon ElastiCache User Guide Which Metrics Should Monitor e Memcached This metric should not exceed 50 MB If it does we recommend that you increase the ConnectionOverhead parameter value Redis At this time we have no recommendation for this parameter you do not need t
187. he requested key was not found The number of non expired items the cache evicted to allow space for new writes The number of get requests the cache has received where the key requested was found The number of get requests the cache has received where the key requested was not found The number of increment requests the cache has received where the key requested was found The number of increment requests the cache has received where the key requested was not found Unit Bytes Bytes Bytes Count Count Count Count Count Count Count Count Count Count Count Count Count Count Count Count Count API Version 2015 02 02 76 Amazon ElastiCache User Guide Metrics for Memcached Metric Reclaimed Description The number of expired items the cache evicted to allow space for new writes For Memcached 1 4 14 the following additional metrics are provided Metric BytesUsedForHash CmdConfigGet CmdConfigSet CmdTouch CurrConfig EvictedUnfetched ExpiredUnfetched SlabsMoved TouchHits TouchMisses Description The number of bytes currently used by hash tables The cumulative number of config get requests The cumulative number of config set requests The cumulative number of touch requests The current number of configurations stored The number of valid items evicted from the least recently used cache LRU which were never touched after being set
188. he service This section discusses specific considerations for connecting to cache nodes in ElastiCache Restricted Commands In order to deliver a managed service experience ElastiCache restricts access to certain cache engine specific commands that require advanced privileges e For cache clusters running Memcached there are no restricted commands e For cache clusters running Redis the following commands are unavailable bgrewriteaof bgsave config debug migrate save slaveof shutdown Cache Node Endpoints and Port Numbers To connect to a cache node your application needs to know the endpoint and port number for that node API Version 2015 02 02 184 Amazon ElastiCache User Guide AWS Management Console AWS Management Console To determine cache node endpoints and port numbers 1 2 3 Sign in to the Amazon ElastiCache Management Console and click Cache Clusters Click the name of your cache cluster Click the Nodes tab All of the nodes in the cache cluster are displayed along with the fully qualified DNS names and port numbers CLI To determine cache node endpoints and port numbers Use the command elasticache describe cache nodes with the following parameter PROMPT gt elasticache describe cache nodes show cache node info This command should produce output similar to the following CACHECLUSTER my memcached https console aws amazon com elastic ache home c
189. he sum of these numbers must equal the value you entered in the Number of Nodes to Add box Add Node x Number of Nodes to Add 4 i Preferred Zone s Specify Zones gt Zone Number of Nodes us west 2a 1 us west 2b 2 us west 2c 1 Apply Immediately Yes ONo Select the Apply Immediately Yes radio button to apply this change immediately or select No to postpone the change until your next maintenance window Impact of New Add and Remove Requests on Pending Requests Scenarios Pending New Re Results Operation quest Scenario 1 Delete Delete The new delete request pending or immediate replaces the pending delete request Scenario 2 Delete Create The new create request pending or immediate replaces the pending delete request Scenario 3 Create Delete The new delete request pending or immediate replaces the pending create request Scenario 4 Create Create The new create request is added to the pending create request Important If the new create request is set to Apply Im mediately Yes all create requests are performed im mediately If the new create request is set to Apply Im mediately No all create requests are pending API Version 2015 02 02 97 Amazon ElastiCache User Guide Adding or Removing Nodes To determine what operations are pending click the Description tab and check to see how many pending creations or deletions are shown You cannot have both pending creations and pendi
190. hen add a list of server endpoints ai Sstatic_client new Memcached Sstatic_client gt setOption Memcached OPT_CLIENT_MODE Memcached STATIC_CLI ENT_MODE Sstatic_client gt addServer server_endpoint Sserver_port API Version 2015 02 02 119 Amazon ElastiCache User Guide Node Auto Discovery Memcached Sstatic_client gt set key value Store the data in the cluster without expiration 2 gt Using the ElastiCache Cluster Client for NET NET client for ElastiCache is open source at https github com awslabs elasticache cluster config net NET applications typically get their configurations from their config file The following is a sample application config file lt xml version 1 0 encoding utf 8 gt lt configuration gt lt configSections gt lt section name clusterclient type Amazon ElastiCacheCluster Cluster ConfigSettings Amazon ElastiCacheCluster gt lt configSections gt lt clusterclient gt lt the hostname and port values are from step 1 above gt lt endpoint hostname mycluster fnjyzo cfg usel cache amazonaws com port 11211 gt lt clusterclient gt lt configuration gt The C program below demonstrates how to use the ElastiCache Cluster Client to connect to a cluster configuration endpoint and add a data item to the cache Using Auto Discovery the program will connect to all o
191. hens Node Type From the list select the node type you want to use for this cluster For information on node types see Parameters for Memcached p 44 Number of Nodes Type in the number of nodes you want launched for this cluster For Memcached you may have from 1 to 20 nodes in a cluster If you want to use the Memcached Flexible Zone Placement functionality type a value between 2 and 20 You incur a charge for each node Click Next Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details To configure your cluster s advanced settings 1 In the Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this cluster associated with e To launch this cluster in a VPC recommended select a VPC subnet group To launch this cluster outside a VPC click Not in VPC The cluster will be launched in the AWS public cloud Availability Zones From the drop down list select how you want the availability zones for the nodes in this cluster determined API Version 2015 02 02 10 Amazon ElastiCache User Guide Step 2 Launch a Memcached Cluster No Preference ElastiCache will select the availability zone for your cluster s nodes All nodes are launched in the same availability zone Spread Nodes Across Zones ElastiCache
192. hich are called read replicas Each replica maintains a copy of the data from the primary cache cluster and uses asynchronous replication mechanisms to keep itself synchronized with the primary API Version 2015 02 02 Amazon ElastiCache User Guide Primary Endpoint cluster Applications can read from any cluster in the replication group Read replicas enhance scalability and guard against data loss Note At this time replication groups are supported only for cache clusters running Redis You can use replication groups to scale your Redis solution for Amazon ElastiCache to handle applications that are highly read intensive or to support large numbers of clients that simultaneously read from the same cache All of the nodes in a replication group must reside in the same region However you can provision read replicas in multiple Availability Zones within that region When you add a read replica to a replication group all of the data from the primary cache cluster is copied to the read replica From that point whenever data is written to the primary the changes are immediately propagated to the read replicas Your applications can connect to the read replica and access data in the cache although they cannot write any data to the replica You can change the roles of the cache nodes within the replication group with the primary cluster and one of the replicas exchanging roles You might decide to do this for performance tuning reasons F
193. iable using the following command C gt set AWS_CREDENTIAL FILE lt the file created above gt 2 Check that your setup works properly run the following command elasticache help You should see the usage page for all ElastiCache commands Environmental Variables Environment variables can be useful for scripting configuring defaults or temporarily overriding them In addition to the AWS_CREDENTIAL_FILE environment variable most API tools included with the ElastiCache Command Line Interface support the following variables EC2_REGION The AWS region to use AWS _ELASTICACHE_URL The URL to use for the service call Not required to specify a different regional endpoint if EC2_REGION is specified or the region parameter is passed API Version 2015 02 02 84 Amazon ElastiCache User Guide Environmental Variables The following examples show how to set the environmental variable EC2_REGION to configure the region used by the API tools Linux OS X or Unix export EC2_REGION us west 1l Windows C gt set EC2_REGION us west l API Version 2015 02 02 85 Amazon ElastiCache User Guide Managing ElastiCache Topics Selecting a Cache Engine and Version p 87 Managing Clusters p 89 Managing Nodes p 116 Managing Replication Groups p 127 Managing Backup and Restore Redis p 139 Managi
194. ies 128 integer Yes Determines the amount of memory used for sorted sets Sorted sets with fewer than the specified number of elements are stored using a special encoding that saves space zset max ziplist value 64 integer Yes Determines the amount of memory used for sorted sets Sorted sets with entries that are smaller than the specified number of bytes are stored using a special encoding that saves space Note If you do not specify a parameter group for your Redis 2 6 13 cluster then a default parameter group default redis2 6 will be used You cannot change the values of any parameters in the default parameter group however you can always create a custom parameter group and assign it to your cluster at any time Node Type Specific Parameters for Redis Although most parameters have a single value some parameters have different values depending on the node type used The following table shows the default values for the maxmemory parameter for each node type The value of maxmemory is the maximum number of bytes available to you for use data and other uses on the node Note The maxmemory parameter cannot be modified Node Type maxmemory cache t1 micro 142606336 cache t2 micro 581959680 cache t2 small 1665138688 API Version 2015 02 02 57 Amazon ElastiCache User Guide Parameters for Redis Node Type cache t2 medium cache m1 small cache m1 medium cache m1 large cache m1 xlarge cache m2 xlarge cache m2
195. ification For information on what actions you can take go to Actions You Can Take When a Node is Sched uled for Replacement p 125 ElastiCache RemoveCacheNodeComplete A cache node has been removed from the cache cluster ElastiCache SnapshotComplete A cache snapshot has completed successfully ElastiCache SnapshotFailed A cache snapshot has failed See the cluster s cache events for more a detailed cause If you describe the snapshot see DescribeSnap shots the status will be failed For more information on using Amazon SNS notifications with ElastiCache see Using Amazon SNS Notifications with ElastiCache p 111 API Version 2015 02 02 195 Amazon ElastiCache User Guide ElastiCache Information in CloudTrail Logging Amazon ElastiCache API Calls Using AWS CloudTrail Amazon ElastiCache is integrated with AWS CloudTrail a service that captures API calls made by or on behalf of ElastiCache in your AWS account and delivers the log files to an Amazon S3 bucket that you specify CloudTrail captures API calls from the ElastiCache console the ElastiCache API or the ElastiCache CLI Using the information collected by CloudTrail you can determine what request was made to ElastiCache the source IP address from which the request was made who made the request when it was made and so on To learn more about CloudTrail including how to configure and enable it go to the AWS CloudTrail User Guide ElastiCache Info
196. ified number of entries are stored using a special encoding that saves space Determines the amount of memory used for hashes Hashes with entries that are smaller than the specified number of bytes are stored using a special encoding that saves space Determines the amount of memory used for lists Lists with fewer than the specified number of entries are stored using a spe cial encoding that saves space Determines the amount of memory used for lists Lists with entries that are smaller than the specified number of bytes are stored using a special encoding that saves space API Version 2015 02 02 54 Amazon ElastiCache User Guide Parameters for Redis Name lua time limit maxclients maxmemory policy maxmemory samples set max intset entries Default Type Modi fi able 5000 integer No 65000 integer No volatile string Yes Iru 3 integer Yes 512 integer Yes Description The maximum execution time for a Lua script in milliseconds be fore ElastiCache takes action to stop the script If Lua time limit is exceeded all Redis commands will return an error ofthe form ____ BUSY Since this state can cause interfer ence with many essential Redis operations ElastiCache will first issue a SCRIPT KILL command If this is unsuccessful ElastiCache will forcibly restart Redis The maximum number of clients that can be connected at one time The eviction policy for keys when maxim
197. ily is automatically created the first time you create a cache cluster without specifying a custom cache parameter group You cannot modify the default memcached1 4 parameter group In this example you modify a parameter in a cache parameter group AWS Management Console The AWS Management Console does not support this functionality Please refer to the command line interface example CLI Use the command elasticache modify cache parameter group to modify a cache parameter group PROMPT gt elasticache modify cache parameter group myCacheParameterGroup para meters name chunk_size value 64 name chunk_size_growth_factor value 1 02 API Call ModifyingCacheParameterGroup with the following parameters e CacheParameterGroupName mycacheparametergroup e Parameters member 1 ParameterName chunk_size e Parameters member 1 ParameterValue 64 e Parameters member 2 ParameterName chunk_size_growth_factor e Parameters member 2 ParameterValue 1 02 API Version 2015 02 02 162 Amazon ElastiCache User Guide Modifying a Cache Parameter Group Example https elasticache us west 2 amazonaws com Action ModifyCacheParameterGroup amp ParameterNameValues member 1 ParameterName chunk_size amp ParameterNameValues member 1 ParameterValue 64 amp ParameterNameValues member 2 ParameterName chunk_size_growth_factor amp ParameterNameValues member 2 ParameterValue 1 02 amp CacheParameterGroupN
198. imary role You might decide to do this for performance tuning reasons For example with a web application with heavy write activity you can choose the node that has the lowest network latency or is closest to your application There is always a lag between the time that data is written to the primary cache cluster and when that data is written to a read replica cache cluster In most cases this lag time will be close to zero seconds however network latency can cause some read replicas in a replication group to fall farther behind If you want to promote a read replica to the primary role we recommend that you choose the read replica with the shortest lag time The AWS Management Console displays replication lag times for read replicas Lag times are also published by CloudWatch using the ReplicationLag metric Important Currently you cannot promote a read replica to primary if the replication group is Multi AZ enabled The following steps are a workaround To promote a replica on a Multi AZ enabled replication group 1 Modify the replication group to disable Multi AZ For guidance on modifying a replication group see Modifying an Existing Redis Replication Group p 135 2 Promote a replica to primary 3 Modify the replication group to re enable Multi AZ AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pa
199. imum statistics for CPUUtilization are useful but the Sum statistic is not All ElastiCache samples are published for a 60 second duration for each individual cache node For any 60 second period a cache node metric will only contain a single sample For further information on how to retrieve metrics for your cache nodes see Viewing Cache Cluster and Cache Node Metrics p 180 Host Level Metrics The following table lists host level metrics provided by ElastiCache for individual cache nodes See Also e Metrics for Memcached p 75 e Metrics for Redis p 78 Metric Description Unit CPUUtilization The percentage of CPU utilization Percent SwapUsage The amount of swap used on the host Bytes FreeableMemory The amount of free memory available on the host Bytes NetworkBytesIn The number of bytes the host has read from the Bytes network NetworkBytesOut The number of bytes the host has written to the Bytes network Metrics for Memcached The following table lists the metrics provided by ElastiCache that are derived from the Memcached stats command Each metric is calculated at the cache node level For complete documentation of the Memcached stats command go to https github com memcached memcached blob master doc protocol txt See Also e Host Level Metrics p 75 API Version 2015 02 02 75 Amazon ElastiCache User Guide Metrics for Memcached Metric BytesUsedForCacheltems BytesReadIntoMemcach
200. in which in turn contains the executable java on Linux and UNIX or java exe on Windows executable To set the Java Home variable 1 Set the Java Home variable On Linux and UNIX enter the following command S export JAVA_HOME lt PATH gt On Windows enter the following command C gt set JAVA_HOME lt PATH gt 2 Confirm the path setting by running JAVA_HOME bin java version and checking the output On Linux UNIX you will see output similar to the following JAVA_HOME bin java version java version 1 6 0_23 Java TM SE Runtime Environment build 1 6 0_23 b05 Java HotSpot TM Client VM build 19 0 b09 mixed mode sharing On Windows you will see output similar to the following C gt SJAVA_HOME bin java version java version 1 6 0_23 Java TM SE Runtime Environment build 1 6 0_23 b05 Java HotSpot TM Client VM build 19 0 b09 mixed mode sharing Getting the Command Line Tools The command line tools are available as a ZIP file on the ElastiCache Developer Tools web site These tools are written in Java and include shell scripts for Windows 2000 XP Vista Windows 7 Linux UNIX and Mac OSX The ZIP file is self contained and no installation is required simply download the zip file and unzip it to a directory on your local machine API Version 2015 02 02 82 Amazon ElastiCache User Guide Setting Up the Tools Setting Up t
201. information see Parameter Groups p 43 Added support for PHP version 5 5 auto discovery May 13 2014 For more information see Insialling the ElastiCache Cluster Client for PHP p 206 API Version 2015 02 02 213 Amazon ElastiCache User Guide Change Backup and restore for Redis clusters Redis 2 8 6 Redis cache engine Support for default Amazon Virtual Private Cloud VPC PHP support for cache node auto discovery Description In this release ElastiCache allows customers to create snapshots of their Redis clusters and create new clusters using these snapshots A snapshot is a backup copy of the cluster at a specific moment in time and consists of cluster metadata and all of the data in the Redis cache Snapshots are stored in Amazon S3 and customers can restore the data from a snapshot into a new cluster at any time For more information see Backup and Restore for Redis Clusters p 38 and Managing Backup and Restore Re dis p 139 ElastiCache supports Redis 2 8 6 in addition to Redis 2 6 13 With Redis 2 8 6 customers can improve the resi liency and fault tolerance of read replicas with support for partial resynchronization and a user defined minimum number of read replicas that must be available at all times Redis 2 8 6 also offers full support for publish and sub scribe where clients can be notified of events that occur on the server ElastiCache offers Redis cache engine s
202. ion ElastiCache provides both host level metrics for example CPU usage and metrics that are specific to the cache engine software for example cache gets and cache misses These metrics are measured and published for each Cache node in 60 second intervals Important You should consider setting CloudWatch alarms on certain key metrics so that you will be notified if your cache cluster s performance starts to degrade For more information see Which Metrics Should Monitor p 79 Dimensions for ElastiCache Metrics All ElastiCache metrics use the AWS ElastiCache namespace and provide metrics for a single dimension the CacheNodeld which is the automatically generated identifier for each cache node in the cache cluster You can find out what these values are for your cache nodes using the DescribeCacheClusters API or elasticache describe cache clusters command line utility Each metric is published under a single set of dimensions When retrieving metrics you must supply both the CacheClusterld and CacheNodeld dimensions See Also API Version 2015 02 02 74 Amazon ElastiCache User Guide Choosing Metric Statistics and Periods e Host Level Metrics p 75 e Metrics for Memcached p 75 e Metrics for Redis p 78 Choosing Metric Statistics and Periods While CloudWatch will allow you to choose any statistic and period for each metric not all combinations will be useful For example the Average Minimum and Max
203. ion To select your cluster s engine 1 yg On the Select Engine screen click the Redis tab 2 Click Next Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Redis Engine To specify your replication group s details 1 Inthe Cluster Specifications section of the Specify Cluster Details page specify settings as shown following a Engine Redis b Engine Version From the drop down list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version c Cache Port Type a new port number for your cluster or leave it at its default value For Redis the default port is 6379 d Parameter Group From the list select a parameter group for this cluster Parameter groups control the run time parameters of your cluster For more information on parameter groups see Parameters for Redis p 48 e Enable Replication To create a Redis replication group leave this check box checked To create a single Redis cluster uncheck this check box f Multi AZ To enable ElastiCache Redis Multi AZ for this replication group leave this check box checked To disable ElastiCache Redis Multi AZ for this replication group uncheck this checkbox The Multi AZ check box is only available when the Enable Replication check box is checked For more information about ElastiCache Redis Multi AZ see Multi AZ with Red
204. ion Medium Utilization and Light Utilization that enable you to optimize your ElastiCache costs based on your expected utilization You can use the command line or the API to list and purchase available reserved cluster offerings Reserved cluster offerings are based on the cluster class and duration In the following example you see how to view available reserved cluster offerings purchase an available reserved cluster offering and list reserved nodes for your account Topics Describing Your Reserved nodes p 106 Describing Available Reserved Cache Node Offerings p 107 e Purchasing a Reserved Cluster p 109 Describing Your Reserved nodes You can get information about reserved nodes for your AWS account as described following AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 In the navigation list click the Reserved Cache Nodes link The reserved cache nodes for your account appear in the Reserved Cache Nodes list You can click any of the reserved cache nodes in the list to see detailed information about the reserved cache node in the detail pane at the bottom of the console CLI To get information about reserved nodes for your AWS account type the following command at a command prompt PROMPT gt elasticache describe reserved cache nodes headers This command should return output similar to the followin
205. is Replication Groups p 32 API Version 2015 02 02 128 Amazon ElastiCache User Guide Creating a Redis Replication Group 2 Inthe Configuration section of the Specify Cluster Details page specify settings as shown following a Replication Group Name Type a meaningful name for this cluster Replication group name constraints are as follows A name must contain from 1 to 16 alphanumeric characters or hyphens e The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens Replication Group Description Type in a meaningful description for this replication group Node Type From the drop down list select the node type you want to use for this cluster For information on node types see Node Type Specific Parameters for Redis p 57 Name of Primary The name of the replication group with 001 added to the end For example if your replication group is named MyGroup then the name of the primary is MyGroup 001 Number of Read Replicas From the drop down list select the number of read replicas you want created for this replication group You must have at least one and no more than five read replicas The default value is 2 Name s of Read Replica s The autogenerated names of the read replicas follow the same pattern as that of the primary cluster s name with a dash and sequential three digit number added to the end beginning with 002 For example if your replication
206. lability Zones see Regions and Availability Zones p 43 Node Considerations for Redis Note At this time ElastiCache supports single node Redis clusters To determine the appropriate size for your cache node we recommend that you estimate the total amount of memory that you will need for your Redis cache and choose a cache node type that has enough memory for your requirements For example if you estimate that the total size of all your items will be 10 GB then you can use a cache m3 xlarge node with 13 3 GB of memory or a cache r3 large node with 13 5 GB of memory If your application is write heavy and you intend to take snapshots we recommend that you have at least as much unused memory in your cluster as you have for your data In this case you d use either a cache m3 2xlarge with 27 9 GB of memory or a cache r3 xlarge with 28 4 GB of memory For an explanation of memory use during a Redis snapshot go to Ensuring That You Have Sufficient Memory to Create a Redis Snapshot p 22 While your cluster is running you can monitor the memory usage processor utilization cache hits and cache misses metrics that are published to CloudWatch If your cluster does not have the desired hit rate or you notice that keys are being evicted too often you can choose a different cache node size with larger CPU and memory specifications You will need to obtain an updated endpoint list from the ElastiCache CLI API or console and configure your clie
207. lable July 30 2014 9 45 59 AM UTI cache r3Jarge memcached 14 14 Muluple Number of Cache Nodes 8 Number of Cache Nodes 8 Number of Nodes Pending Creation Number of Nodes Pending Creation NIA Nodes Pending Deteton 0001 0003 0007 Configuraion Endpoint s Nodes Pending Deletion Configuration Endpoint gt te a 4 Auto Minor Version Upgrade Yes Auto Minor Version Upgrade Yes Notification ARN Disabled Notification ARN Disabled Cache Subnet Group Cache Subnet Group Security Group s default active Secunty Group s default active Cache Parameter Group default memcached1 4 in sync twec01 30 tue 02 30 WA Cache Parameter Group default memcached1 4 in s Maintenance Viindow tue 04 30 tue 02 30 Maintenance Window Replication Group r 5 Click the Nodes tab 6 Tocancel all pending operations click the Cancel Pending button The Cancel Pending dialog box appears 7 Confirm that you want to cancel all pending operations by clicking the Cancel Pending button or to keep the operations click Cancel Modifying a Cluster In addition to adding or removing nodes from a cluster there can be times where you need to make other changes to an existing cluster such as adding a security group changing the maintenance window or a parameter group and such We recommend that you have your maintenance window fall at the time of lowest usage Thus it might need modificati
208. lastiCache cache node access is restricted to applications running on whitelisted Amazon EC2 instances You can control the Amazon EC2 instances that can access your cache cluster by using cache subnet groups and cache security groups By default all new ElastiCache cache clusters are launched in an Amazon Virtual Private Cloud Amazon VPC environment You can use cache subnet groups to grant cache cluster access from Amazon EC2 instances running on specific subnets If you choose to run your cache cluster outside of Amazon VPC you can create cache security groups to authorize Amazon EC2 instances running within specific Amazon EC2 security groups Supported Operations To work with caching infrastructure components ElastiCache offers a set of operations that you can invoke from the AWS Management Console the ElastiCache command line interface CLI or the ElastiCache application programming interface API Cache Cluster Operations ElastiCache provides operations to create modify and delete cache clusters You can use the CreateCacheCluster operation to launch a new cache cluster specifying the number and type of cache nodes the cache engine software to use Memcached or Redis and other configuration parameters Once the cache cluster is launched you can use the DescribeCacheClusters operation to view information about the cluster including the host names and port numbers of the cache nodes your application can then connect to
209. lastiCache cluster only from an Amazon EC2 instance that is running in the same Amazon VPC In this case you will need to grant network ingress to the cluster To grant network ingress from an Amazon VPC security group to a cluster 1 Sign in to the AWS Management Console and open the Amazon EC2 console at https console amazonaws cn ec2 2 Inthe left navigation pane under Network amp Security click Security Groups 3 In the list of security groups click the security group for your Amazon VPC If you are a new ElastiCache user this security group will be named default 4 Click Inbound tab and then do the following API Version 2015 02 02 16 Amazon ElastiCache User Guide You Launched Your Cluster into EC2 Classic Click Edit Click Add rule In the Type column select Custom TCP rule In the Port range box type the port number for your cache cluster node This number must be the same one that you specified when you launched the cluster The default ports are as follows ao 7 e Memcached port 11211 e Redis port 6379 e Inthe Source box select Anywhere which has the port range 0 0 0 0 0 so that any Amazon EC2 instance that you launch within your Amazon VPC can connect to your ElastiCache nodes f Click Save When you launch an Amazon EC2 instance into your Amazon VPC that instance will be able to connect to your ElastiCache cluster You Launched Your Cluster into EC2 Classic If you launched
210. lasticache cluster client memcached for java This library is based on the API Version 2015 02 02 117 Amazon ElastiCache User Guide Node Auto Discovery Memcached popular Soymemcached client The ElastiCache Cluster Client is released under the Amazon Software License http www amazonaws cn asl You are free to modify the source code as you see fit you can even incorporate the code into other open source Memcached libraries or into your own client code Note To use the ElastiCache Cluster Client for PHP you will first need to install it on your Amazon EC2 instance For more information see Installing the ElastiCache Cluster Client for PHP p 206 To use the ElastiCache Cluster Client for NET you will first need to install it on your ElastiCache instance For more information see Installing the ElastiCache Cluster Client for NET p 210 Step 3 Modify Your Application Program You are now ready to modify your application program so that it uses Auto Discovery The following sections show how to use the ElastiCache Cluster Client for Java PHP and NET Topics e Using the ElastiCache Cluster Client for Java p 118 Using the ElastiCache Cluster Client for PHP p 119 Using the ElastiCache Cluster Client for NET p 120 Using the ElastiCache Cluster Client for Java The program below demonstrates how to use the ElastiCache Cluster Client to connect to a cluster configuration endpoint and add a data item t
211. le https elasticache us west 2 amazonaws com Action CreateCacheCluster amp CacheClusterId my redis primary amp CacheNodeType cache ml small amp Engine redis amp NumCacheNodes 1 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp SnapshotArns member 1l arn 3Aaws 3As3 3A 3A 33Amy bucket 2Fdump rdb amp Timestamp 20141201T2203022Z amp Version 2014 12 01 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Credential lt credential gt amp X Amz Date 20141201T2203022 amp X Amz Expires 20141201T2203022Z amp X Amz SignedHeaders Host amp X Amz Signature lt signature gt Creating a single Redis cluster ElastiCache supports replication when you use the Redis engine To monitor the latency between when data is written to a Redis read write primary cluster and when it is propagated to a read only secondary cluster ElastiCache adds to the cluster a special key ElastiCacheMasterReplicationTimestamp which is the current Universal Coordinated Time UTC time Because a Redis cluster might be added to a replication group at a later time this key is included in all Redis clusters even if initially they are not members of a replication group For more information on replication groups see Replication Groups and Read Replicas Redis p 30 To create a Redis cluster do the following Prerequisites 1 Sign in to the AWS Management Console and open the Amazon Elasti
212. lects the second cluster in the replication group the first read replica as the source for the snapshots Note In a replication group we recommend that you do not take snapshots on the primary cache cluster Instead you should designate one of the read replicas as the snapshotting cluster For more information see Performance Impact of Snapshots p 40 The following sections contain procedures showing you how to enable automatic snapshots for a read replica in a replication group AWS Management Console To enable automatic snapshots for a read replica in a replication group using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache API Version 2015 02 02 144 Amazon ElastiCache User Guide Enabling Automatic Snapshots for a Replication Group 2 On the ElastiCache console dashboard click Replication Groups 3 To select the replication group to enable automatic backups on click the name of the replication group 4 Click Modify 5 Inthe Modify Replication Group dialog do the following a Set Enable Automatic Backups to Yes In the Cluster Id list select one of the read replicas to act as the snapshotting cluster c Inthe Backup Retention Period drop down list select the number of days that you want to retain your daily snapshots d If you want to specify a particular backup window click Select Window and s
213. lete the value in the Value text box to the right of the tag s key name or type a value API Version 2015 02 02 70 Amazon ElastiCache User Guide AWS CLI Manage Tags x Apply tags to your resources to help organize and identify them Atag consists of a case sensitive key value pair For example you could define a tag with key Name and value Webserver Learn More about tagging your AWS resources Applied Tags Key Value Delete Service ElastiCache w Region B Add Tags Cancel Apply Changes 6 When finished click Apply Changes to keep your changes or Cancel to discard your changes AWS CLI You can use the AWS CLI to modify the tags on an ElastiCache resource To modify the value of a tag use add tags to resource to add the tag with the new value or use remove tags from resource to remove specified tags from the resource ElastiCache API You can use the ElastiCache API to modify the tags on an ElastiCache resource To modify the value of a tag use AddTagsToResource action to add tags or use RemoveTagsFromResource to remove tags from the resource Removing Tags from Your ElastiCache Resource You can remove one or more tags from a resource using the ElastiCache management console AWS CLI or ElastiCache API Topics e ElastiCache Management Console p 72 e AWS CLI p 72 e ElastiCache API p 73 API Version 2015 02 02 71 Amazon ElastiCache User Guide ElastiCache Management Console Ela
214. lient download 2013 07 09T22 12 42 151Z cache tl micro mem cached available 1 us west 2a 1 4 14 CACHESECURITYGROUP default active CACHEPARAMETERGROUP default memcachedl 4 in sync CACHENODE 0001 availabl my memcached f310xz cache amazonaws com 11211 in sync CACHECLUSTER my redis primary https console aws amazon com elastic ache home client download 2013 07 10T22 47 16 586Z cache ml small redis available 1 us west 2a 2 6 13 repgroup01 CACHESECURITYGROUP default active CACHEPARAMETERGROUP default redis2 6 in sync CACHENODE 0001 available my redis primary f310xz 0001 cache amazonaws com 6379 in sync CACHECLUSTER my redis replica 0Ol https console aws amazon com elastic ache home client download 2013 07 10T23 11 07 704Z cache ml small redis available 1 us west 2b 2 6 13 repgroup01 CACHESECURITYGROUP default active CACHEPARAMETERGROUP default redis2 6 in sync CACHENODE 0001 availabl my redis replica 01 310xz 0001 cache amazonaws com 6379 in sync The fully qualified DNS names and port numbers are in the CACHENODE lines in the output API To determine cache node endpoints and port numbers Call DescribeCacheClusters with the following parameter API Version 2015 02 02 185 Amazon ElastiCache User Guide Auto Discovery e ShowCacheNodeInfo true E
215. loud you can create a virtual network in the AWS cloud that closely resembles a traditional data center You can configure your Amazon VPC including selecting its IP address range creating subnets and configuring route tables network gateways and security settings The basic functionality of ElastiCache is the same in a virtual private cloud ElastiCache manages software upgrades patching failure detection and recovery whether your clusters are deployed inside or outside an Amazon VPC ElastiCache cache nodes deployed outside an Amazon VPC are assigned an IP address to which the endpoint DNS name resolves This provides connectivity from Amazon Elastic Compute Cloud Amazon EC2 instances When you launch an ElastiCache cluster into an Amazon VPC private subnet every cache node is assigned a private IP address within that subnet For guidance on using ElastiCache with an Amazon Virtual Private Cloud see Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 Overview of ElastiCache In an Amazon VPC The following diagram and table describe the Amazon VPC environment along with ElastiCache clusters and Amazon EC2 instances that are launched in the Amazon VPC API Version 2015 02 02 60 Amazon ElastiCache User Guide Overview of ElastiCache In an Amazon VPC VPC 10 0 0 0 16 Amazon Web Services Sey R eo ba La Security Group 4 s s O Subnet Cache Cluster R
216. lowing RESERVATION ReservationId Class Start Time Dura tion Fixed Pric Usage Pric Count State Description Offering Type RESERVATION myreservationid cache ml small 2013 12 19T00 30 23 2472Z ly 455 00 USD 0 092 USD 1 payment pending memcached Medium Utilization API The following example shows purchasing a specific reserved cluster offering 649fd0c8 cf6d 47a0 bfa6 060f8e75e95f with a reserved cluster ID of myreservationID Call the PurchaseReservedCacheNodesOf fering action with the following parameters API Version 2015 02 02 110 Amazon ElastiCache User Guide Using Amazon SNS Notifications with ElastiCache ReservedCacheNodesOfferingId 649fd0c8 cf6d 47a0 bfab6 060f8e75e95F e ReservedCacheNodeID myreservationID CacheNodeCount 1 Example https elasticache us west 2 amazonaws com Action PurchaseReservedCacheNodesOffering amp ReservedCacheNodesOf feringld 649fd0c8 cf6d 47a0 bfab6 060f8e75e95f amp ReservedCacheNodeID myreservationID amp CacheNodeCount 1 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This call returns output similar to the following
217. lowing CACHECLUSTER my cache cluster 2013 07 26T01 21 46 607Z2 cache ml large mem cached available 3 us west 2c 1 4 5 SECGROUP default active PARAMGRP default memcached1l 4 in sync NOTIFICATION arn aws sns us west 2 565419523791 ElastiCacheNotifications active API To add or modify an Amazon SNS topic for a cluster call the ModifyCacheCluster action with the following parameters e CacheClusterId my cache cluster TopicArn arn aws sns us west 2 565419523791 ElastiCacheNotifications This call returns output similar to the following API Version 2015 02 02 112 Amazon ElastiCache User Guide Using Amazon SNS Notifications with ElastiCache Example https elasticache amazon com Action ModifyCacheCluster ApplyImmediately fals amp CacheClusterId my cache cluster amp NotificationTopicArn arn 3Aaws 3Asns 3Aus west 2 3A565419523791 3AElastiC acheNotifications amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Enabling and Disabling Amazon SNS Notifications You can turn notifications on or off for a cluster The following procedures show you how
218. luster p 99 2 Add anew node to the cluster For instructions go to Adding Nodes To A Cluster p 96 3 If you are not using Node Auto Discovery Memcached p 116 on this cluster in your application replace the old node s endpoint with the new node s endpoint If you manually replace the node there will be redistribution of keys and resulting cache misses Redis Do nothing Doing nothing will result in the node being replaced as scheduled ElastiCache will automatically replace the node with a new node If the cluster is a standalone cluster it will initially be empty If the cluster is a member of a replication group it will sync with the primary cluster Replace a read replica If the cluster is a read replica in a replication group replace the cluster 1 Delete the cluster that is scheduled for replacement For instructions go to Deleting a Cache Cluster p 114 2 Add a new replica to replace the one you just deleted For instructions go to Adding a Read Replica To a Replication Group p 133 API Version 2015 02 02 125 Amazon ElastiCache User Guide Actions You Can Take When a Node is Scheduled for Replacement 3 In your application replace the old cluster s endpoint with the new cluster s endpoint Replace the primary If the cluster is a primary cluster in a replication group promote a read replica to primary then delete the cluster 1 Promote a read replica to primary For instr
219. luster Client To download the ElastiCache Cluster Client for PHP 1 2 3 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache From the ElastiCache console click Download ElastiCache Cluster Client Choose the ElastiCache Cluster Client that matches your PHP version and AMI architecture and click the Download ElastiCache Cluster Client button Installation Steps for New Users To install on an Amazon Linux AMI 2014 03 64 bit and 32 bit 1 2 Launch an Amazon Linux instance either 64 bit or 32 bit and log into it Install PHP dependencies sudo yum install gcc c php php pear Download the correct php memcached package for your Amazon EC2 instance and PHP version For more information see Downloading the Installation Package p 206 Install php memcached The URI should be the download path for the installation package sudo pecl install lt package download path gt Here is a sample installation command for PHP 5 4 64 bit Linux In this sample replace x y z with the actual version number sudo pecl install home AmazonElastiCacheClusterClient X Y Z PHP54 64bit tgz Note Please use the latest version of the install artifact With root sudo permission add a new file named memcached ini in the etc php d directory and insert extension amazon elasticache cluster client so in the file API Versio
220. luster at any time By default the new cluster will have the same configuration that the source cluster did when the snapshot was created however you can override some of the parameters such as node size API Version 2015 02 02 40 Amazon ElastiCache User Guide Deleting Snapshots During the restore operation ElastiCache creates the new cluster and then populates the Redis cache with data from the snapshot file When this process is complete the Redis cache is warmed up and the cluster is ready to accept requests For more information see Restoring a Snapshot to a New Cluster p 149 Deleting Snapshots An automatic snapshot is automatically deleted when its retention limit expires If you delete a cluster all of its automatic snapshots are also deleted If you delete a replication group all of the automatic snapshots from the clusters in that group are also deleted Note When you delete a cluster or a replication group you have the option of taking a final snapshot before the deletion begins In the case of a replication group the snapshot is taken at the primary node ElastiCache provides a deletion API that lets you delete a snapshot at any time regardless of whether the snapshot was created automatically or manually Since manual snapshots do not have a retention limit manual deletion is the only way to remove them For more information see Deleting Snapshots p 153 Clusters A cluster is a collection o
221. maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default API Version 2015 02 02 141 Amazon ElastiCache User Guide Enabling Automatic Snapshots on a New Cluster We recommend specifying a maintenance window so that downtime for maintenance will have the least impact upon your business b Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see http aws amazon com sns 4 Click Next Step 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings To review your settings and launch your cluster 1 Review all your settings to ensure each value is what you want 2 If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launch Replication Group to create your cluster or replication group 3 To return to the Cache Clusters screen click Close on the Success screen Your cluster will have the status creating while it is being created When the status changes to available it s ready for use Note As soon as your cluster bec
222. mary cluster during certain types of planned maintenance or in the unlikely event of a primary or Availability Zone failure As part of the failover process ElastiCache also propagates the DNS address of the promoted replica so that if your application is writing to the primary endpoint no endpoint change will be required in your application However because your application reads from individual endpoints you will need to change the read endpoint of the promoted replica to the replacement replica s endpoint The failover process generally takes 3 to 4 minutes This process is much faster than replacing the primary and syncing the data from a replica which occurs in the event of a primary node failure if you don t enable Multi AZ for your Redis replication group Notes on Multi AZ with Redis Replication Groups The following points should be noted Redis replication is asynchronous Therefore when a primary cluster fails over to a replica a small amount of data might be lost due to replication lag When selecting the replica to promote to primary ElastiCache selects the replica with the least replication lag the one that is most current When you enable Multi AZ on a replication group a replica cluster cannot be manually promoted to primary Thus if the primary in AZ 1 fails over to a replica in AZ 2 the primary cluster stays in AZ 2 To promote the new replica in AZ 1 to primary you must first disable Multi AZ on the replication
223. mazon SNS Notifications with ElastiCache p 111 Deleting a Cache Cluster p 114 Creating a Cluster When you create a new cluster you need to name it specify the engine software to use Memcached or Redis and choose the number and type of nodes If you are creating a Redis cluster you can seed it with data from ElastiCache for Redis snapshots or from your own rdb files stored in Amazon Simple Storage Service For more information see Migrating Your Redis Cluster to ElastiCache p 151 If you are creating a Memcached cluster or a Redis replication group you can specify whether you want all the clusters or nodes in a single availability zone or in multiple availability zones For more information on availability zones see Locating Your Redis Read Replicas and Memcached Nodes p 43 AWS Management Console The following topics show you how to create a cluster using the Amazon ElastiCache console Topics Creating a Memcached cluster p 89 using the AWS Management Console Creating a single Redis cluster p 93 using the AWS Management Console Creating a Memcached cluster When you use the Memcached engine Amazon ElastiCache supports horizontally partitioning your data over multiple nodes Memcached enables auto discovery so you don t need to keep track of the endpoints for each node Memcached tracks each node s endpoint updating the endpoint list as nodes are added and removed All your application needs to interact
224. mcached Although most parameters have a single value some parameters have different values depending on the node type used The following table shows the default values for the max_cache_memory and num_threads parameters for each node type Note The max_cache_memory and num_threads parameters cannot be modified Node Type max_cache_memory num_threads cache t1 micro 213 1 cache t2 micro 555 1 cache t2 small 1588 1 cache t2 medium 3301 2 cache m1 small 1300 1 cache m1 medium 3350 1 cache m1 large 7100 2 cache m1 xlarge 14600 4 cache m2 xlarge 16700 2 cache m2 2xlarge 33800 4 cache m2 4xlarge 68000 8 cache m3 medium 2850 1 cache m3 large 6200 2 cache m3 xlarge 13600 4 cache m3 2xlarge 28600 8 cache c1 xlarge 6600 8 cache r3 large 13800 2 cache r3 xlarge 29100 4 API Version 2015 02 02 47 Amazon ElastiCache User Guide Parameters for Redis Node Type max_cache_memory num_threads cache r3 2xlarge 59600 8 cache r3 4xlarge 120600 16 cache r3 8xlarge 242600 32 Parameters for Redis Topics Redis 2 8 19 Added Parameters p 48 e Redis 2 8 6 Added Parameters p 48 e Redis 2 6 13 Parameters p 51 Node Type Specific Parameters for Redis p 57 e Append Only Files AOF p 58 If you do not specify a parameter group for your Redis cluster then a default parameter group will be used either default redis2 6 or default redis2 8 You cannot change the values of any parameters in the default parameter group however
225. memory New touch commands and counters API Version 2015 02 02 41 Amazon ElastiCache User Guide Redis Clusters Memcached 1 4 5 Memcached 1 4 5 was the first release supported by ElastiCache Redis Clusters Redis is a key value store that supports abstract data types and optional data durability A Redis cluster consists of a single cache node you can scale up by using a larger cache node For more information go to http redis io ElastiCache supports the following versions of Redis Redis 2 8 19 Redis 2 8 19 adds several bug fixes and new features since 2 8 6 HyperLogLog In processing data determining the exact cardinality of a data set is proportional to the size of the data set When processing big data the memory requirements for determining the exact cardinality is prohibitive HyperLogLog estimates cardinality with a variance of 0 81 0 0081 while using only 12K of memory plus a little bit for overhead HyperLogLog is supported with the Redis commands PFADD PFCOUNT and PFMERGE Lexicographical range queries When querying a sorted set of strings you can use ZRANGEBYLEX to retrieve all the values in a range for example all the names between Abdul and Barak Other commands that support Lexicographic range queries include ZLEXCOUNT and ZREMRANGEBYLEX Bug fixes lIncluding preventing a primary node from sending stale data to replica nodes by failing the master SYNC when a background save bgsave
226. ms The default values for the memcached_connections_overhead parameter satisfy most use cases however the required amount of allocation for connection overhead can vary depending on multiple factors including request rate payload size and the number of connections You can change the value of the memcached_connections_overhead to better suit the needs of your application For example increasing the value of the memcached_connections_overhead parameter API Version 2015 02 02 46 Amazon ElastiCache User Guide Parameters for Memcached will reduce the amount of memory available for storing cache items and provide a larger buffer for connection overhead while decreasing the value of the memcached_connect ions_overhead parameter will give you more memory to store cache items but can increase your risk of swap usage and degraded performance If you observe swap usage and degraded performance try increasing the value of the memcached_connections_overhead parameter Important For the cache t1 micro node type the value for memcached_connections_overhead is determined as follows e If your cluster is using the default parameter group ElastiCache will set the value for memcached_connections_overhead to 13MB e If your cluster is using a parameter group that you have created yourself you can set the value for memcached_connections_overhead to a value of your choice Node Type Specific Parameters for Me
227. n group If you want your replication group s primary to automatically failover to a read replica you must enable Multi AZ either when you create the replication group or later by modifying the replication group For more information on Multi AZ enabled replication groups see Multi AZ with Redis Replication Groups p 32 To create a Redis replication group you have the following options Create a Redis replication group by creating the primary cluster secondary cluster s and replication group at the same time from the ElastiCache management console for guidance see Creating a Redis Multiple Cluster Replication Group p 127 CLI see the automatic failover enabled a option in elasticache create replication group API see the Automat icFailoverEnabled optional parameter in CreateReplicationGroup Create a replication group using an existing Redis cluster as the primary cluster for guidance see AWS Management Console p 131 or CLI p 132 or API p 132 sections of this topic Then modify the replication group to enable Multi AZ for guidance see Modifying an Existing Redis Replication Group p 135 Creating a Redis Multiple Cluster Replication Group If you already have a Redis cache cluster that you want to use as the primary cluster in a replication group the best way to create the replication group is using the create replication group process See the AWS Management Console p 131 or CLI p 132 or
228. n 2015 02 02 207 Amazon ElastiCache User Guide Installation Steps for New Users echo extension amazon elasticache cluster client so sudo tee etc php d memcached ini To install on a Red Hat Enterprise Linux 7 0 AMI 64 bit and 32 bit 1 Launch a Red Hat Enterprise Linux instance either 64 bit or 32 bit and log into it 2 Install PHP dependencies sudo yum install gcc c php php pear 3 Download the correct php memcached package for your Amazon EC2 instance and PHP version For more information see Downloading the Installation Package p 206 4 Install pnp memcached The URI should be the download path for the installation package sudo pecl install lt package download path gt 5 With root sudo permission add a new file named memcached ini in the etc php d directory and insert extension amazon elasticache cluster client so in the file echo extension amazon elasticache cluster client so sudo tee etc php d memcached ini Other Linux distributions On some systems notably CentOS7 and Red Hat Enterprise Linux RHEL 7 1 libsas12 so 3 has replaced 1ibsas12 so 2 On those systems when you load the ElastiCache cluster client it attempts and fails to find and load 1ibsas12 so 2 To resolve this issue create a symbolic link to libsas12 so0 3 so that when the client attempts to load libsas12 so 2 it is redirected to libsas12 so 3 The follo
229. n VPC API actions are part of the Amazon EC2 reference Information for the network administrator who Amazon VPC Network Administrator Guide needs to configure the gateway at your end of an optional IPsec VPN connection For more detailed information about Amazon Virtual Private Cloud go to http www amazonaws cn vpc Cache Engine Version Management You can control if and when the protocol compliant software powering your cache cluster is upgraded to new versions that are supported by ElastiCache This level of control enables you to maintain compatibility with specific Memcached or Redis versions test new versions with your application before deploying in production and perform version upgrades on your own terms and timelines Because version upgrades involve some compatibility risk they will not occur automatically and must be initiated by you You initiate version upgrades to your cluster by modifying the cluster and specifying a new engine version Note Although cache engine version management functionality is intended to give you as much control as possible over how patching occurs ElastiCache reserves the right to patch your cluster on your behalf in the event of a critical security vulnerability in the system or cache software Warning Changing a cache engine version is a disruptive process which clears all cache data in the cluster Maintenance Window Every cluster has a weekly maintenance window during which any system
230. n about Amazon VPC security groups see http docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Security p 5 and Managing Cache Security Groups p 175 2 Inthe Backup section of the Configure Advanced Settings page specify settings as shown following Enable Automatic Backups To schedule regular automatic backups of your cluster check this check box Unchecked Default Leaving this unchecked means that ElastiCache will not schedule automatic backups of this cluster If you want a backup you must create a manual backup For more information see Creating a Manual Snapshot p 146 Checked Checking this checkbox causes ElastiCache to schedule regular automatic backups of this cluster You can also perform manual backups if you so choose When this checked box is checked the console expands so you can specify the number of days a backup is to be retained before deleting and optionally specify when you want the automatic backups scheduled If you do not specify the schedule automatic backups are created on a schedule set by ElastiCache 3 Inthe Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window The screen expands so you can specify the day of the week to start maintenance the UTC time to start
231. n programming interface API This section provides an overview of working with backup and restore for clusters running on Redis Constraints At this time backup and restore is supported only for clusters running on Redis Backup and restore is not supported on cache t1 micro or cache t2 cache nodes All other cache node types are supported Costs ElastiCache allows you to store one snapshot for each active Redis cluster free of charge Storage space for additional snapshots is charged at a rate of 0 085 GB per month for all regions There are no data transfer fees for creating a snapshot or for restoring data from a snapshot to a Redis cluster Automatic Snapshots For any Redis cluster you can enable automatic snapshots where ElastiCache creates a snapshot of the cluster on a daily basis Automatic snapshots can help guard against data loss In the event of a node failure you can create a new cluster restoring all of your data from the most recent snapshot The result is a warm started Redis cluster pre loaded with your data and ready for use When you configure an automatic snapshot you should consider the following settings Snapshot window A period during each day when ElastiCache will begin creating a snapshot The minimum length for the snapshot window is 60 minutes You can set the snapshot window for any time when it s most convenient for you or for a time of day that avoids doing snapshots during a particularly
232. n this example the retention period is 3 days API Version 2015 02 02 143 Amazon ElastiCache User Guide Enabling Automatic Snapshots for a Replication Group PROMPT gt elasticache modify cache cluster cache cluster id my redis primary snapshot retention limit 3 API To enable automatic snapshots on an existing cluster use the Modi fyCacheCluster action with the following parameters e CacheClusterld e SnapshotRetentionLimit set this parameter to a nonzero value to enable automatic snapshots The following example enables automatic snapshots by setting SnapshotRetentionLimit to a nonzero value in this example the retention period is 3 days Example https elasticache us west 2 amazonaws com Action ModifyCacheCluster amp SnapshotRetentionLimit 3 amp CacheClusterId my redis primary amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T220302Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Enabling Automatic Snapshots for a Replication Group For replication groups you can designate one cluster in the group as the snapshotting cluster ElastiCache will perform snapshots on this cluster only By default ElastiCache se
233. n to Amazon ElastiCache DAT207 Accelerating Application Performance with Amazon ElastiCache AWS re Invent 2013 In this video learn how you can use Amazon ElastiCache to easily deploy a Memcached or Redis compatible in memory caching system to speed up your application performance We show you how to use Amazon ElastiCache to improve your application latency and reduce the load on your database servers We ll also show you how to build a caching layer that is easy to manage and scale as your application grows During this session we go over various scenarios and use cases that can benefit by enabling caching and discuss the features provided by Amazon ElastiCache DAT207 Accelerating Application Performance with Amazon ElastiCache re Invent 2013 Advanced Videos For advanced videos about Amazon ElastiCache see the following Topics DAT307 Deep Dive into Amazon ElastiCache Architecture and Design Patterns re Invent 2013 p 3 SDD402 Amazon ElastiCache Deep Dive re Invent 2014 p 3 API Version 2015 02 02 2 Amazon ElastiCache User Guide Are You a First Time ElastiCache User DAT307 Deep Dive into Amazon ElastiCache Architecture and Design Patterns re Invent 2013 In this video we examine caching caching strategies scaling out monitoring and compare the Memcached and Redis engines During this session we review best practices and design patterns related to Amazon ElastiCache DAT307 Deep
234. ne click Replication Groups 3 Inthe Replication Groups list select the replication group where you want to promote a replica by clicking on its name API Version 2015 02 02 134 Amazon ElastiCache User Guide Modifying an Existing Redis Replication Group 4 Inthe details pane at the bottom of the screen scroll down to the list of clusters and click Promote behind the read replica that you want to promote 5 Inthe Promote Read Replica dialog box click Promote The replication group s status will change to modifying When the status changes to available the former replica is now your primary and you can use the replication group CLI To promote a read replica to the primary role use the elast icache modify replication group command with the primary cluster id option The following example promotes my replica 1 to primary status and my redis primary becomes a read replica PROMPT gt elasticache modify replication group my repgroup primary cluster id my replica 1l API To promote a read replica cache cluster to the primary role use the Modi fyReplicationGroup action with the PrimaryClusterId parameter The following example promotes my replica 1 to primary status and my redis primary becomes a read replica Example https elasticache us west 2 amazonaws com Action ModifyReplicationGroup amp ReplicationGroupId my repgroup amp PrimaryClusterlId my replica 1l amp Version 2014 12 01
235. nes ds ian oes ewan sas Nao a daea toate ces estates Vaak 83 Providing Credentials for the Tools ccceeeeee eect e eee eee een eee ee ee een reeset ee neta eea een een ena es 84 Environmental Variables vsc s cvensesrestaedeateeneactactacdeauesnen soos shectateeteeates sere nau etiee sted e A EROT 84 Managing ElastiCache srecni eae ok Peed deen eat shed de ea die deat ee eee een 86 API Version 2015 02 02 iv Amazon ElastiCache User Guide Selecting a Cache Engine and Version ccceeeeee eee eee eee eee eee eee eee nent teeta tenet a ee neea eed 87 Memeached or Redis csiis inane ceteris val ea en descend a ee eee eee 87 MemcCached Versi n S niese niteni aaaea aeta a Give age e eE da yeaa eet aad a Ka EAA 87 Redis Versions tvvsa katei ated ecient divi ae al a ela EEN EEE AEE EEEO 88 Managing Cl Stels irantan Undone a fed dees wees Delt eee foe Mane tien does Tee a gene 89 Creating a Cluster sstcccis divine el Baars aaa detainee deta Jed E E e RA E ies Seale 89 Adding or Removing Nodes cececeeeee cece ee eee een eea een eea een eea nea esa een eeaeeaesaeeaesaeegeeaeeneeaes 96 Modifying a Cluster oevereetre monta ei ehh av nee hiv ela ested EE EE S 104 Managing Reserved Nodes cceceneenee cece ee eee teense tea eea ee aeeaeeaeeaeeaeeaeeaeeaeeaeeaeeaeeaeeaes 106 Using Amazon SNS Notifications with ElastiCache ccceceeeeeeeneeeeee eee eea eee een eee eeneeaeenes 111 Deleting
236. ng deletions Cache Cluster mycacheciuster Nodes Cache Cluster mycachecluster Cache Cluster Details Cache Ciuster ID mycachectuster Status available Cache Cluster Details Cache Cluster ID mycachectuster Status available Creation Time July 30 2014 9 45 59 AM UTC 7 Cache Node Type cache r3Jarge Engine memcached Engine Version 1 4 14 Availability Zone Multiple Number of Cache Nodes 8 Number of Nodes Pending Creation 2 Nodes Pending Deletion NWA Configuration Endpoint Cache Node Type cache r3 large Engine memcached Engine Version 1 4 14 Availability Zone Multiple Number of Cache Nodes 8 Number of Nodes Pending Creation NIA Nodes Pending Deletion 0001 0003 0007 o e _ h e oo ee oe Auto Minor Version Upgrade Yes Notification ARN Disabled Cache Subnet Group Security Group s default active Cache Parameter Group default memcached1 4 in sync Maintenance Window tvec01 30 tue 02 30 Replication Group WA Auto Minor Version Upgrade Yes Notification ARN Disabled Cache Subnet Group Security Group s default active Maintenance Window tue 04 30 tue 02 30 9 Click the Add button After a few moments the new nodes will show up in the nodes list with a status of creating If they don t refresh your browser page CLI To add nodes to a cluster using the command line interface use the command elasticache m
237. ng Cache Parameter Groups p 155 Using ElastiCache with Amazon Virtual Private Cloud VPC p 164 Managing Cache Subnet Groups p 171 Managing Cache Security Groups p 175 Viewing Cache Cluster and Cache Node Metrics p 180 Viewing ElastiCache Events p 182 This section covers the ElastiCache operations you are most likely to use and provides procedural instruction and examples API Version 2015 02 02 86 Amazon ElastiCache User Guide Selecting a Cache Engine and Version Selecting a Cache Engine and Version Amazon ElastiCache supports two cache engines Memcached and Redis Each engine provides some advantages Use the information in this topic to help you select the engine that best meets your requirements Memcached or Redis On the surface Memcached and Redis look similar Both are in memory key stores However in practice there are significant differences Select Memcached if you have these requirements You want the simplest model possible You need to run large nodes with multiple cores or threads You need the ability to scale out adding and removing nodes as demand on your system increases and decreases You want to shard your data across multiple nodes You need to cache objects such as a database Select Redis if you have these requirements You need complex data types such as strings hashes lists and sets You need to sort or rank in memory data sets You want persistence of your k
238. ns by default and we recommend using persistent cache node connections when using ElastiCache Client side DNS caching can occur in multiple places including client libraries the language runtime or the client operating system You should review your application configuration at each layer to ensure that you are frequently resolving IP addresses for your cache nodes API Version 2015 02 02 188 Amazon ElastiCache User Guide Using the Query API Using the ElastiCache API Topics Using the Query API p 189 Available Libraries p 191 Troubleshooting Applications p 191 This section provides task oriented descriptions of how to use and implement ElastiCache operations For a complete description of these operations see the Amazon ElastiCache API Reference For information about ElastiCache regions and endpoints go to Regions and Endpoints in the Amazon Web Services General Reference Using the Query API Query Parameters HTTP Query based requests are HTTP requests that use the HTTP verb GET or POST and a Query parameter named Action Each Query request must include some common parameters to handle authentication and selection of an action Some operations take lists of parameters These lists are specified using the param n notation Values of n are integers starting from 1 Query Request Authentication You can only send Query requests over HTTPS and you must include a signature in every Query request
239. nsion lt absolute path to amazon elasticache cluster client so gt in the file echo extension lt absolute path to amazon elasticache cluster client so gt sudo tee etc php5 cli conf d memcached ini To install for SUSE Linux Enterprise Server 11 AMI 64 bit or 32 bit po Launch a SUSE Linux instance either 64 bit or 32 bit and log into it Install PHP dependencies sudo zypper install gcc php53 devel Download the correct php memcached package for your Amazon EC2 instance and PHP version For more information see Downloading the Installation Package p 206 Install php memcached The URI should be the download path for the installation package sudo pecl install lt package download path gt With root sudo permission add a new file named memcached ini in the etc php5 conf d directory and insert extension amazon elasticache cluster client so in the file echo extension amazon elasticache cluster client so sudo tee etc php5 conf d memcached ini Note If Step 5 doesn t work for any of the previous platforms please verify the install path for amazon elasticache cluster client so and specify the full path of the binary in the extension Also verify that the PHP in use is a supported version We support versions 5 3 through 5 5 API Version 2015 02 02 209 Amazon ElastiCache User Guide For Users Who Already Have php memcached Extension Installed
240. nt Console To restore a snapshot to a new cluster using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Snapshots In the list of snapshots select the one that you want to restore and then click Restore Snapshot 4 Inthe Restore Cache Cluster window type a name for the new cache cluster in the Cache Cluster Id box 5 Optional You can customize your cluster by selecting new values for Instance Type Cache Port and other properties 6 When the settings are as you want them click Launch Cache Cluster w CLI To restore data from a snapshot into a new cluster use the elasticache create cache cluster command with the snapshot name parameter The following example creates a new cache cluster named my restored redis and restores the data from my manual snapshot into it PROMPT gt elasticache create cache cluster my restored redis snapshot name my manual snapshot API To restore data from a snapshot into a new cluster use the CreateSnapshot action with the following parameter e SnapshotName The following example creates a new cluster named my restored redis and restores the data from my manual snapshot into it Example https elasticache us west 2 amazonaws com Action CreateCacheCluster amp SnapshotName my snapshot copy amp CacheCluster
241. nt for Efficient Load Balancing Note This section applies to multirnode Memcached clusters To effectively use multiple ElastiCache Memcached nodes you need to be able to spread your cache keys across the nodes A simple way to load balance a cluster with n nodes is to calculate the hash of API Version 2015 02 02 24 Amazon ElastiCache User Guide Consistent Hashing Using Java the object s key and mod the result by n hash key mod n The resulting value 0 through n 1 is the number of the node where you place the object This approach is simple and works well as long as the number of nodes n is constant However whenever you add or remove a node from the cluster the number of keys that need to be moved is n 1 n where nis the new number of nodes Thus this approach will result in a large number of keys being moved which translates to a large number of initial cache misses especially as the number of nodes gets large Scaling from 2 to 3 nodes results in 2 1 2 50 percent of the keys being moved the best case Scaling from 9 to 10 nodes results in 10 1 10 90 percent of the keys being moved If you re scaling up due to a spike in traffic you don t want to have a large number of cache misses A large number of cache misses results in hits to the database which is already overloaded due to the spike in traffic The solution to this dilemma is consistent hashing Consistent hashing uses an algorithm such that
242. nt output buf fer limit pubsub soft limit bytes for longer than this number of seconds the client will be disconnected For Redis read replicas If a cli ent s output buffer reaches the specified number of bytes the cli ent will be disconnected API Version 2015 02 02 53 Amazon ElastiCache User Guide Parameters for Redis Name client output buffer limit slave soft limit client output buffer limit slave soft seconds databases hash max ziplist entries hash max ziplist value list max ziplist entries list max ziplist value Default 67108864 60 16 512 64 512 64 Type integer integer integer integer integer integer integer Modi fi able No No No Yes Yes Yes Yes Description For Redis read replicas If a cli ent s output buffer reaches the specified number of bytes the cli ent will be disconnected but only if this condition persists for cli ent output buffer limit slave soft seconds For Redis read replicas If a cli ent s output buffer remains at client output buffer lim it slave soft limit bytes for longer than this number of seconds the client will be discon nected The number of databases You can specify a different value for databases when you create a cluster but cannot change it once the cluster is available Determines the amount of memory used for hashes Hashes with fewer than the spec
243. nts to use this new node Reserved Nodes Reserved cache nodes let you make a one time up front payment for a cache node and reserve the cache node for a one or three year term at significantly lower rates Reserved cache nodes are available in three varieties Heavy Utilization Medium Utilization and Light Utilization that enable you to optimize your ElastiCache costs based on your expected utilization You can use the command line tools the API or the AWS Management Console to list and purchase available reserved cache node offerings The three types of reserved cache node offerings are based on class and duration Reserved Node Offerings Heavy Utilization reserved cache nodes enable workloads that have a consistent baseline of capacity or run steady state workloads Heavy Utilization reserved cache nodes require the highest up front commitment but if you plan to run more than 79 percent of the reserved cache node term you can earn the largest savings up to 70 percent off of the On Demand price Unlike the other reserved cache nodes with Heavy Utilization reserved cache nodes you pay a one time fee followed by a lower hourly fee for the duration of the term regardless of whether or not your cache node is running Medium Utilization reserved cache nodes are the best option if you plan to leverage your reserved cache nodes a substantial amount of the time but you want either a lower one time fee or the flexibility to stop API
244. o set a CloudWatch alarm for it Evictions This is a cache engine metric published for both Memcached and Redis cache clusters We recommend that you determine your own alarm threshold for this metric based on your application needs e Memcached If your exceed your chosen threshold scale you cache cluster up by using a larger cache node type or scale out by adding more cache nodes e Redis lf you exceed your chosen threshold scale your cache cluster out by adding read replicas CurrConnections This is a cache engine metric published for both Memcached and Redis cache clusters We recommend that you determine your own alarm threshold for this metric based on your application needs Whether you are running Memcached or Redis an increasing number of CurrConnections might indicate a problem with your application you will need to investigate the application behavior to address this issue API Version 2015 02 02 80 Amazon ElastiCache User Guide Prerequisites Setting Up the ElastiCache Command Line Interface This section describes the prerequisites for running the command line tools where to get the command line tools how to set up the tools and their environment and includes a series of common examples of tool usage Important The Amazon ElastiCache Command Line Interface CLI does not support any ElastiCache improvements after API version 2014 09 30 To use newer ElastiCache functionality from the command line use
245. o the cache Using Auto Discovery the program will connect to all of the nodes in the cluster without any further intervention package com amazon elasticache import java io IOException import java net InetSocketAddress import net spy memcached MemcachedClient This is the AWS provided library with Auto Discovery support public class AutoDiscoveryDemo public static void main String args throws IOException String configEndpoint mycluster fnjyzo cfg usel cache amazonaws com Integer clusterPort 11211 MemcachedClient client new MemcachedClient new InetSocketAddress con figEndpoint clusterPort The client will connect to the other cache nodes automatically Store a data item for an hour The client will decide which cache host will store this item client set theKey 3600 This is the data value API Version 2015 02 02 118 Amazon ElastiCache User Guide Node Auto Discovery Memcached Using the ElastiCache Cluster Client for PHP The program below demonstrates how to use the ElastiCache Cluster Client to connect to a cluster configuration endpoint and add a data item to the cache Using Auto Discovery the program will connect to all of the nodes in the cluster without any further intervention Note To use the ElastiCache Cluster Client for PHP you will first need to install it on your Amazon EC2 instance For more information see Installin
246. odify Reboot You can also use the elasticache describe cache clusters command with the show cache node info parameter Example elasticache describe cache clusters show cache node info CACHECLUSTER mycluster mycluster fnjyzo cfg usel cache amazonaws com 11211 https console aws amazon com elasticache home client download 2013 07 30T00 57 50 911Z cache ml small memcached available 2 us west 2a 1 4 14 SECGROUP default active PARAMGRP default memcachedl 4 in sync NOTIFICATION arn aws sns us west 2 740835402826 autodiscovery active Important Please ensure that you are using the latest version of the ElastiCache Command Line Toolkit To download the toolkit go to http Awww amazonaws cn developertools Amazon ElastiCache Step 2 Download the ElastiCache Cluster Client To take advantage of Auto Discovery client programs must use the ElastiCache Cluster Client The ElastiCache Cluster Client is available for Java PHP and NET and contains all of the necessary logic for discovering and connecting to all of your cache nodes To download the ElastiCache Cluster Client 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console www amazonaws cn elasticache 2 From the ElastiCache console click ElastiCache Cluster Client then click Download The source code for the ElastiCache Cluster Client for Java is available at https github com amazonwebservices aws e
247. odify cache cluster with the following parameters PROMPT gt elasticache modify cache cluster my cache cluster num cache nodes 5 apply immediately This command produces output similar to the following CACHECLUSTER my cache cluster 2013 07 06T23 34 09 756Z cache ml large mem cached modifying 3 us west 2b 1 4 5 5 SECGROUP default active PARAMGRP default memcached1l 4 in sync API To add nodes to a cluster using the API e Callthe ModifyCacheCluster action with the following parameters e CacheClusterId my cache cluster e NumCacheNodes 5 e ApplyImmediately true API Version 2015 02 02 98 Creation Time July 30 2014 9 45 59 AM UTC OMAQUIABON Endpoint seamen cemete tp ae Cache Parameter Group default memcached1 4 in s Amazon ElastiCache User Guide Adding or Removing Nodes The following example shows the results of a call to add nodes to a cluster Example https elasticache us west 2 amazonaws com Action ModifyCacheCluster ApplyImmediately true amp NumCacheNodes 5 amp CacheClusterId my cache cluster amp Version 2014 12 01 SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signatu
248. odifyCacheParameterGroup lasticache DescribeCacheParameterGroups lasticache DescribeCacheParameters lasticache ResetCacheParameterGroup elasticache DescribeEngineDefaultParameters Resource oooodeoa a oa Failure to Retrieve Account Attributes Recent changes to ElastiCache may cause an error for some IAM users that were set up with permissions based on the ElastiCache Full Access AWS managed policies The error may display Failed to retrieve account attributes certain console functions may be impaired shown at the top of the page or Error calling EC2 DescribeSecurityGroups The error is caused by the console invoking actions that have not explicitly been given permissions in the ElastiCache Full Access policies In order to resolve this issue your IAM administrator must update the IAM user s policy document to allow two additional Amazon EC2 actions ec2 DescribeAccountAttributes and c2 DescribeSecurityGroups You must make this change for any IAM user or group that was assigned a policy that was based on the ElastiCache Full Access AWS managed policies API Version 2015 02 02 204 Amazon ElastiCache User Guide Failure to Retrieve Account Attributes For example the following code is the default policy document for the ElastiCache Full Access AWS managed policy Version 2012 10 17 Statement Effect Allow Action elasticache
249. of Step 3 Configure Advanced Settings following ElastiCache supports replication when you use the Redis engine To monitor the latency between when data is written to a Redis read write primary cluster and when it is propagated to a read only secondary cluster ElastiCache adds to the cluster a special key Elast iCacheMasterReplicationTimestamp which is the current Universal Coordinated Time UTC time Because a Redis cluster might be added to a replication group at a later time this key is included in all Redis clusters even if initially they are not members of a replication group For more information on replication groups see Replication Groups and Read Replicas Redis p 30 To create a Redis cluster do the following Prerequisites 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 On the ElastiCache console dashboard click Launch Cache Cluster to start the Launch Cache Cluster wizard API Version 2015 02 02 139 Amazon ElastiCache User Guide Enabling Automatic Snapshots on a New Cluster Step 1 Select the Redis Engine Before you proceed be sure you have completed the Prerequisites section To select your cluster s engine 1 On the Select Engine screen click the Redis tab YZ 2 Click Next Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Redis Engine To configure
250. of the week to start maintenance the UTC time to start maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default We recommend specifying a maintenance window so that downtime for maintenance will have the least impact upon your business Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see htip aws amazon com sns 4 Click Next Step 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings To review your settings and launch your cluster 1 Review all your settings to ensure each value is what you want 2 If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launch Replication Group to create your cluster or replication group API Version 2015 02 02 130 Amazon ElastiCache User Guide Creating a Redis Replication Group 3 To return to the Cache Clusters screen click Close on the Success screen Your cluster will have the status creating while it is being created When the status changes to available it s r
251. oftware Memcached or Redis The ElastiCache API lets you control cluster wide attributes such as the number of cache nodes security settings version upgrades and system maintenance windows Cache Parameter Groups Cache parameter groups are an easy way to manage runtime settings for supported cache engine software Both Memcached and Redis have many parameters to control memory usage cache eviction policies item sizes and more a cache parameter group is a named collection of Memcached or Redis specific parameters that you can apply to a cache cluster thereby guaranteeing that all of the nodes in that cluster are configured in exactly the same way Cache Replication Groups If you are running a single node Redis cache cluster you can create a replication group for that cluster and then add one or more read replicas A replication group consists of one primary cache cluster for handling read write traffic plus additional cache clusters that act as read only replicas of the primary ElastiCache ensures that the read replicas are continually synchronized with the primary and in the event API Version 2015 02 02 4 Amazon ElastiCache User Guide Security of a primary cache node failure rebuilds the primary using data from one of the surviving read replicas In this way replication groups allow you to scale your read only traffic while guarding against data loss caused by hardware failure Security For enhanced security E
252. oftware in addition to Memcached Customers who currently use Redis can seed a new ElastiCache Redis cache cluster with their existing data from a Redis snapshot file easing migration to a managed ElastiCache environment To support Redis replication capabilities the ElastiCache API now supports replication groups Customers can create a replication group with a primary Redis cache node and add one or more read replica nodes that automatically stay synchronized with cache data in the primary node Read intensive applications can be offloaded to a read replica reducing the load on the primary node Read replicas can also guard against data loss in the event of a primary cache node failure In this release ElastiCache is fully integrated with Amazon Virtual Private Cloud VPC For new customers cache clusters are created in an Amazon VPC by default For more information see ElastiCache and Amazon Virtual Private Cloud p 60 The initial release of cache node auto discovery provided support for Java programs In this release ElastiCache brings cache node auto discovery support to PHP Date Changed April 24 2014 March 13 2014 September 3 2013 January 8 2013 January 2 2013 API Version 2015 02 02 214 Amazon ElastiCache User Guide Change Support for Amazon Virtual Private Cloud VPC Cache node auto discovery and new cache engine ver sion New cache node types Reserved cache nodes
253. omes available you re billed for each hour or partial hour that the cluster is active even if you re not using it CLI To create a new cluster with automatic snapshots use the elasticache create cache cluster command The following example creates a new Redis cluster named my redis primary To enable automatic snapshots set snapshot retention limit to a nonzero value in this example the retention period is 5 days PROMPT gt elasticache create cache cluster cache cluster id my redis primary snapshot retention limit 5 engine redis cache node type cache ml small num cache nodes 1 API To create a new cluster with automatic snapshots use the Creat eCacheCluster action with the following parameters CacheClusterId e SnapshotRetentionLimit Engine CacheNodeType e NumCacheNodes API Version 2015 02 02 142 Amazon ElastiCache User Guide Enabling Automatic Snapshots for an Existing Cluster The following example creates a new Redis cluster named my redis primary To enable automatic snapshots set SnapshotRetentionLimit to a nonzero value in this example the retention period is 5 days Example https elasticache us west 2 amazonaws com Action CreateCacheCluster amp CacheNodeType cache ml small amp SnapshotRetentionLimit 5 amp NumCacheNodes 1 amp CacheClusterId my redis primary amp Engine redis amp Version 2014 12 01 amp SignatureVersion 4 amp Signature
254. on from time to time Making Changes to a Cluster The following procedures show you how to make changes to a cluster For the purpose of this example we assume that the cluster named my cache cluster exists AWS Management Console To modify a cluster using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Cluster The Cache Clusters list appears 3 Inthe Cache Clusters list click the name of the cluster you want to modify The Modify Cache Cluster window appears 4 Inthe Modify Cache Cluster window make the modification s you want API Version 2015 02 02 104 Amazon ElastiCache User Guide Modifying a Cluster 5 Click Modify The modifications are made immediately and you return to the Cache Clusters screen CLI To modify a cluster use the elast icache modify cache cluster command The following example uses the parameter preferred maintenance window to modify my cache cluster S0 its maintenance window is each Tuesday from 4 00P to 5 00P UTC PROMPT gt elasticache modify cache cluster my cache cluster preferred mainten ance window Tue 04 00 Tue 05 00 This command produces output similar to the following CACHECLUSTER my cache cluster 2013 07 06T23 34 09 756Z cache ml large mem cached available 3 us west 2b 1 4 5 SECGROUP d
255. on group see Creating a Redis Multiple Cluster Replication Group p 127 In the Configuration section of the Specify Cluster Details page specify settings as shown following a Cluster Name Type a meaningful name for this cluster Cluster name constraints are as follows A name must contain from 1 to 20 alphanumeric characters or hyphens The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens b Node Type From the list select the node type you want to use for this cluster For information on node types see Node Type Specific Parameters for Redis p 57 c 3 Location of Redis RDB file Amazon S3 location of the rdb file used to seed this cluster If this is left blank this cluster will not be seeded upon creation For more information on snapshots and seeding a Redis cluster see Backup and Restore for Redis Clusters p 38 and Migrating Your Redis Cluster to ElastiCache p 151 Click Next Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details To configure your cluster s advanced settings 1 In the Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this cluster associated with e To launch this cluster in a VPC recommended select a VPC subnet group
256. or example with a web application that has heavy write activity you can choose the node that has the lowest network latency For more information see Promoting a Read Replica to the Primary Role p 134 Replication groups guard against potential data loss if a primary or secondary node is unexpectedly terminated For more information see Multi AZ with Redis Replication Groups p 32 Tip For greater reliability and faster recovery we recommend that you create one or more read replicas in different availability zones for your cluster and enable Multi AZ on the replication group instead of using AOF AOF is disabled for Multi AZ replication groups AOF is not supported for cache nodes of type cache t1 micro For more information on AOF and Multi AZ see and Multi AZ with Redis Replication Groups p 32 Primary Endpoint An application can connect to any node in a replication group provided that it has the DNS endpoint and port number for that node Read only applications can connect to any node in the replication group but all write activity must take place at the primary node Every replication group has a primary endpoint which is a DNS name that always resolves to the primary node in the replication group The primary endpoint is immune to changes to your replication group such as promoting a read replica to the primary role Even if you make changes to the replication group such as promoting a read replica to become the new primary
257. ot When you restore from a snapshot the tags on the snapshot are copied to the cluster The following list describes the characteristics of an ElastiCache cost allocation tag key and value e The tag key is the required name of the tag The key s string value can be from 1 to 128 Unicode characters long and cannot be prefixed with aws The string can contain only the set of Unicode letters digits white space and API Version 2015 02 02 65 Amazon ElastiCache User Guide Adding Tags to Your ElastiCache Resource The tag value is the required value of the tag The value s string value can be from 1 to 256 Unicode characters in length and cannot be prefixed with aws The string can contain only the set of Unicode letters digits white space and Values do not have to be unique in a tag set For example you can have a tag set where the keys Service and Application both have the value ElastiCache AWS does not apply any semantic meaning to your tags tags are interpreted strictly as character strings AWS does not automatically set any tags on any ElastiCache resource You can add list modify or remove tags from an ElastiCache resource by using the ElastiCache management console AWS CLI or ElastiCache API Important Amazon ElastiCache tagging is not supported by the ElastiCache CLI Use the AWS CLI instead Topics Adding Tags to Your ElastiCache
258. ou want to remove PROMPT gt elasticache describ cache clusters my cach cluster sn This command produces output similar to the following CACHECLUSTER my cache cluster memcached available 5 us west 2b 1 4 5 SECGROUP default active 2013 07 06T23 34 09 7562 cache ml large API Version 2015 02 02 101 Amazon ElastiCache User Guide Adding or Removing Nodes PARAMGRP default memcached1 4 in sync CACHENODE 0001 2013 07 14T23 39 51 273Z available my cache cluster m2st2p fsw4 uselgqa cache amazonaws com 11211 in sync CACHENODE 0002 2013 07 14T23 39 51 276Z available my cache cluster m2st2p fsw7 uselqa cache amazonaws com 11211 in sync CACHENODE 0003 2013 07 06T23 34 09 756Z available my cache cluster m2st2p fswc uselqa cache amazonaws com 11211 in sync CACHENODE 0004 2013 07 06T23 34 09 756Z available my cache cluster m2st2p fswd uselqa cache amazonaws com 11211 in sync CACHENODE 0005 2013 07 06T23 34 09 756Z available my cache cluster m2st2p fswf uselqa cache amazonaws com 11211 in sync 2 Use the command elasticache modify cache cluster with a list of the nodes to remove as in the following example PROMPT gt elasticache modify cache cluster my cache cluster num cache nodes 3 nodes to remove 0004 0005 apply immediately This command produces ou
259. our Amazon VPC to be reachable from the Internet you need to assign a static public address called an Elastic IP address to the instance Prerequisites In order to create an ElastiCache cluster within an Amazon VPC your Amazon VPC must meet the following requirements The Amazon VPC must allow nondedicated Amazon EC2 instances You cannot use ElastiCache in an Amazon VPC that is configured for dedicated instance tenancy A cache subnet group must be defined for your Amazon VPC ElastiCache uses that cache subnet group to select a subnet and IP addresses within that subnet to associate with your cache nodes A cache security group must be defined for your Amazon VPC or you can use the default provided CIDR blocks for each subnet must be large enough to provide spare IP addresses for ElastiCache to use during maintenance activities Routing and Security You can configure routing in your Amazon VPC to control where traffic flows for example to the Internet gateway or virtual private gateway With an Internet gateway your Amazon VPC has direct access to other AWS resources that are not running in your Amazon VPC If you choose to have only a virtual private gateway with a connection to your organization s local network you can route your Internet bound traffic over the VPN and use local security policies and firewall to control egress In that case you incur additional bandwidth charges when you access AWS resources over the Internet
260. ownload the ElastiCache NET Cluster Client for ElastiCache To download the ElastiCache NET cluster client 1 Sign in to the AWS Management Console and open the ElastiCache console at htips console amazonaws cn elasticache On the left navigation pane click ElastiCache Cluster Client 3 Inthe Download ElastiCache Memcached Cluster Client list select NET and then click Download API Version 2015 02 02 210 Amazon ElastiCache User Guide Install AWS Assemblies with NuGet Install AWS Assemblies with NuGet NuGet is a package management system for the NET platform NuGet is aware of assembly dependencies and installs all required files automatically NuGet installed assemblies are stored with your solution rather than in a central location such as Program Files so you Can install versions specific to an application without creating compatibility issues Installing NuGet NuGet can be installed from the Installation Gallery on MSDN go to https visualstudiogallery msdn microsoft com 27077b70 9dad 4c64 adcf c7cf6bc9970c If you are using Visual Studio 2010 or later NuGet is automatically installed You can use NuGet from either Solution Explorer or Package Manager Console Using NuGet from Solution Explorer To use NuGet from Solution Explorer in Visual Studio 2010 1 From the Tools menu select Library Package Manager 2 Click Package Manager Console To use NuGet from Solution Explorer in Visual Studio 2012 o
261. p 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings To review your settings and launch your cluster 1 Review all your settings to ensure each value is what you want 2 If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launch Replication Group to create your cluster or replication group 3 To return to the Cache Clusters screen click Close on the Success screen Your cluster will have the status creating while it is being created When the status changes to available it s ready for use Note As soon as your cluster becomes available you re billed for each hour or partial hour that the cluster is active even if you re not using it Step 5 Delete the Cluster Optional To delete a cluster As soon as the cluster status changes to deleted you stop incurring charges for that cluster 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache 2 Inthe ElastiCache console dashboard click Cache Clusters 3 Inthe list of clusters to select the cluster to delete click the box to the left of the cluster s name When selected the box will have a colored center You can only delete one cluster at a time from the ElastiCache console Selecting multiple clusters disables the Delete button 4 Click the Delete button
262. pe EE Ee ha P EE dete kE SEERE aR ESA 42 Regions and Availability Zones 1 0 0 0 cece eee eee eee nea e nea e deta eed eta ee anea ne aeeanenes 43 Locating Your Redis Read Replicas and Memcached Nodes 0 csceeeeeeeeeeeeeeeeeeeeeaeees 43 Parameter Groups w2issivesccstesesdeceer each oe cei veeac ads denis ecto ues ie need ie sl eer ee aca AEE 43 Parameters for MEMCached ccceeeec eee eeceece eee eee ece eee ece eee e ii ia Eiaa i E DRE NE 44 Parameters for Redis inisenisi meirino arerioa e eai dbadin viene vedi yee dan O aN nei 48 Subnet Groups e Seront e aa e a an eta aE A A ach A A A a A A N a 59 Sec rity Groups neeaae e ieai E E As eee A ee cm ea 59 ElastiCache and Amazon Virtual Private Cloud ccceeeeeee eee e terete reese tees eee eed eea een eeaeeaeeaeeaes 60 Overview of ElastiCache In an Amazon VPC ccceeeeeeeee nee ee eee e een eea een eea een eea een eeaeeaeeaeeaes 60 Prerequisites as t oen nae a n a ton dag E a a deeds ie feet sea tied 62 Routing and Security irsi eainiie EE E A E E E AE EEE O N 62 Amazon VPC D c me ntatioN eiss inesse rase ridea n aaea aiaa aa A Aaa EOT EE ia SG ATE 62 Cache Engine Version Management cececeeee eee ne tees eee eee eee teeta ee neta ee neta eea ee eea een eea een rent 63 Maintenance Window i meneren n gered a cgessane de a e Aa aaa A A e o a 63 Using Cost Allocation Tags in ElastiCache ccceceeeeee teen e eee teeta teeta eed neate
263. ps select the one you want to modify 4 Inthe lower portion of the ElastiCache console make any changes to the description or the list of subnet IDs for the cache subnet group To save your changes click Save ad API Version 2015 02 02 172 Amazon ElastiCache User Guide Modifying a Cache Subnet Group CLI Use the command elasticache modify cache subnet group to modify a cache subnet group PROMPT gt elasticache modify cache subnet group mycachesubnetgroup description New description subnet ID list subnet 42df9c3a subnet 48fc21a9 This command should produce output similar to the following SUBNETGROUP mycachesubnetgroup Testing vpc 5a2e4c35 SUBNE subnet 42df9c3a us west 2b SUBNE subnet 48fc21a9 us west 2b API Call ModifyCacheSubnetGroup with the following parameter e CacheSubnetGroupName mycachesubnetgroup Example https elasticache us west 2 amazonaws com Action DeleteCacheSubnetGroup amp CacheSubnet GroupName mycachesubnetgroup amp CacheSubnetGroupDescription New S20description amp SubnetIds member 1 ssubnet 42df 9c3a amp SubnetIds member 2 subnet 48fc21a9 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022Z amp X Amz Algorithm AWS4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201
264. pt of your Amazon EC2 instance type the following commands wget http download redis io redis stable tar gz tar xvzf redis stable tar gz cd redis stable make At the command prompt of your Amazon EC2 instance type the following command substituting the endpoint of your cluster for the one shown in this example PROMPT gt src redis cli h mycachecluster eaogs8 0001 usw2 cache amazonaws com p 6379 You will see a Redis command prompt similar to the following redis mycachecluster eaogs8 0001 usw2 cache amazonaws com 6379 gt You are now connected to the cluster and can run Redis commands The following is an example API Version 2015 02 02 20 Amazon ElastiCache User Guide Step 5 Delete Your Cache Cluster set a hello Set key a with a string value and no expiration OK get a Get value for key a hello get b Get value for key b results in miss nil quit Exit from redis cli Step 5 Delete Your Cache Cluster To delete a cluster As soon as the cluster status changes to deleted you stop incurring charges for that cluster 1 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache In the ElastiCache console dashboard click Cache Clusters In the list of clusters to select the cluster to delete click the box to the left of the cluster s name When selected t
265. r Visual Studio 2013 1 From the Tools menu select NuGet Package Manager 2 Click Package Manager Console From the command line you can install the assemblies using Install Package as shown following Install Package Amazon ElastiCacheCluster To see a page for every package that is available through NuGet such as the AWSSDK and AWS Extensions assemblies go to the NuGet website at http www nuget org The page for each package includes a sample command line for installing the package using the console and a list of the previous versions of the package that are available through NuGet For more information on Package Manager Console commands go to http nuget codeplex com wikipage title Package 20Manager 20Console 20Command 20Reference 20 28v1 3 29 API Version 2015 02 02 211 Amazon ElastiCache User Guide Document History The following table describes the important changes to the documentation since the last release of the Amazon ElastiCache User Guide API version 2015 02 02 Latest documentation update June 11 2015 Change Node replacement messages added Support for Redis v 2 8 19 Description ElastiCache added three messages pertaining to sched uled node replacement 1 mentScheduled cheduled and Canceled FlastiCache NodeReplac EFlastiCache NodeReplacementRes BlastiCache NodeReplacement For more information and actions you can take
266. r eens deen een eea een eea een eeaneaes 65 Adding Tags to Your ElastiCache Resource ccceeeeeee eee e ee eee eee eee eee eceeeeeceeseeeeeeeeseeeeeseeeeeeeees 66 ElastiCache Management Console cceeeeeee eee e eee e eee eee e eee eee ee neta eea een eea eee een ee eeneeaes 66 AWS GE lis n tta eds a teen fee eee ee eee 67 ElastiCache API scecccncas dedcees tigated sar a hs ass cadsaeetenata ace dedele pda Ea E dh 68 Listing the Tags for an ElastiCache Resource cceeeeee eee eee een eee eeceeeeeaeeeeeaeeeeeaeeseeaeeseeaeeneeaes 68 ElastiCache Management Console cccceeeeee eee e ee eee e eee eee etre renee eee ee eee ee eens een enees 69 AWS CE lef soct end ances cape ete ee enc aes eat eee eo i ae eee ee eee 69 ElastiCache AP neninn o EE E eens ee eddaee EE AE EDE 69 Modifying Tags on Your ElastiCache Resource ceeeeeeee eee e eter eee ee eee een eee tenet a een eee eea een eeneeaes 70 ElastiCache Console esie eee adel rent hee eck ainda edie edie die 70 AWS GE Is ctr Aegean eee ede ete Ge ee ees 71 ElastiCache API nimiae Menai a es ie aed a ES a EEN a G 71 Removing Tags from Your ElastiCache Resource cceeeeeeee eee e eee teeta tenet eee n teats neta een eeaeeaeeaeenes 71 ElastiCache Management Console cceeeceee eee e ee eee e teeter eee eee reeset eee eea een een eset erage 72 PWS CEP cena et ee ioe gece as eee o eee ee ee 72 ElastiCache APIs sissies A ee eas
267. ration endpoint Process of Connecting to Cache Nodes I z he application resolves the configuration endpoint s DNS name Because the configuration endpoint maintains CNAME entries for all of the cache nodes the DNS name resolves to one of the nodes the client can then connect to that node API Version 2015 02 02 121 Amazon ElastiCache User Guide Node Auto Discovery Memcached I p gt he client requests the configuration information for all of the other nodes Since each node maintains configuration information for all of the nodes in the cluster any node can pass configuration inform ation to the client upon request he client receives the current list of cache node hostnames and IP addresses It can then connect to all of the other nodes in the cluster Note The client program refreshes its list of cache node hostnames and IP addresses once per minute This polling interval can be adjusted if necessary Normal Cluster Operations When the application has connected to all of the cache nodes ElastiCache Cluster Client determines which nodes should store individual data items and which nodes should be queried for those data items later The following sequence diagram shows the process of normal cluster operations ElastiCache Cluster ElastiCache Cluster Client get key Process of Normal Cluster Operations Determine correct node through consist
268. re gt Removing Nodes from a Cluster AWS Management Console To remove nodes from a cluster using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe left navigation pane click Cache Clusters 3 Inthe Cache Clusters list locate the Nodes column and click the number of nodes link of the cluster you want to modify Filter All Cache Clusters Q x 4 Clusters Cache Cluster Engine Nodes Node we codes Status b a mycacheciuster memea n _Snoses gt her ol aeailadle The detail panel appears 4 Click the Nodes tab The list of nodes for the cluster appears 5 Inthe Nodes list do the following 1 Click the check box next to the nodes you want to remove from the cluster 2 Click the Delete Node button API Version 2015 02 02 99 Amazon ElastiCache User Guide Adding or Removing Nodes 6 Inthe Delete Node confirmation dialog box 1 2 Cache Cluster mycacheciuster P Node D Status Port ie 0001 availadle 11211 mA awailadle 0003 availadie 11211 Ni Oo lt he Nodes Zone 7 US west 2a 7 us west 2b The Delete Node confirmation dialog box appears Verify that the nodes scheduled for deletion are the correct ones Select Apply Immediately Yes to apply this change immediately or No to postpone the change until your next maintenance win
269. reate a single Redis cluster uncheck this check box To create a Redis replication group see Creating a Redis Multiple Cluster Replication Group p 127 2 Inthe Configuration section of the Specify Cluster Details page specify settings as shown following a Cluster Name Type a meaningful name for this cluster Cluster name constraints are as follows A name must contain from 1 to 20 alphanumeric characters or hyphens e The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyphens Node Type From the list select the node type you want to use for this cluster For information on node types see Node Type Specific Parameters for Redis p 57 S3 Location of Redis RDB file Amazon S3 location of the rdb file used to seed this cluster If this is left blank this cluster will not be seeded upon creation For more information on snapshots and seeding a Redis cluster see Backup and Restore for Redis Clusters p 38 and Migrating Your Redis Cluster to ElastiCache p 151 3 Click Next Step 3 Configure Advanced Settings Before you proceed be sure you have completed Step 2 Specify Cluster Details To configure your cluster s advanced settings 1 Inthe Network amp Security section of the Configure Advanced Settings page specify settings as shown following a Cache Subnet Group From the dropdown list select the subnet group you want this cluster associated with
270. requisites section To select your cluster s engine 1 On the Select Engine screen click the Memcached tab in 2 Click Next Step 2 Specify Cluster Details Before you proceed be sure you have completed Step 1 Select the Memcached Engine API Version 2015 02 02 9 Amazon ElastiCache User Guide Step 2 Launch a Memcached Cluster To configure your cluster s specifications and details 1 In the Cluster Specifications section of the Cluster Details page specify settings as shown following a b Engine Memcached Engine Version From the list select the version of the cache engine to run for this cluster Unless you have a specific reason not to we recommend you select the latest engine version Port Type a new port number for your cluster or leave it at its default value For Memcached the default port is 11211 Parameter Group From the list select a parameter group for this cluster Parameter groups control the run time parameters of your cluster For more information on parameter groups see Parameters for Memcached p 44 In the Configuration section of the Specify Cluster Details page specify settings as shown following a Cluster Name Type a meaningful name for this cluster Cluster name constraints are as follows A name must contain from 1 to 20 alphanumeric characters or hyphens The first character must be a letter A name cannot end with a hyphen or contain two consecutive hyp
271. ring Yes everysec string Yes Description Determines whether to enable Redis active rehashing feature The main hash table is rehashed ten times per second each rehash operation consumes 1 millisecond of CPU time You can specify a different value for activerehashing when you create a cluster but cannot change it once the cluster is up and running Enables or disables Redis append only file feature AOF AOF cap tures any Redis commands that change data in the cache and is used to recover from certain node failures The default value is no meaning AOF is turned off Set this para meter to yes to enable AOF For more information see Ap pend Only Files AOF p 58 Note Append Only Files AOF is not supported for cache t1l1 micro and cache t2 nodes For nodes of this type the appendonly parameter value is ignored Note For Multi AZ replication groups AOF is disabled Controls how often the AOF out put buffer is written to disk e no the buffer is flushed to disk on an as needed basis everysec the buffer is flushed once per second This is the default always the buffer is flushed every time that data in the cache is modified API Version 2015 02 02 52 Amazon ElastiCache User Guide Parameters for Redis Name client output buffer limit normal hard limit client output buffer limit normal soft limit client output buffer limit normal soft seconds
272. riod drop down list boxes and Time Range tab to change the metrics being displayed CLI To gather CPU utilization statistics for a cache cluster e Use the CloudWatch command mon get stats with the following parameters note that the start end end times are shown as examples only you will need to substitute your own appropriate start and end times PROMPT gt mon get stats CPUUtilization dimensions CacheClusterId my cachecluster CacheNodeId 0002 statistics Average namespace AWS ElastiCache start time 2013 07 05T00 00 00 end time 2013 07 06T00 00 00 period 60 API Version 2015 02 02 180 Amazon ElastiCache User Guide API API To gather CPU utilization statistics for a cache cluster e Call the CloudWatch API GetMetricStatistics with the following parameters note that the start end end times are shown as examples only you will need to substitute your own appropriate start and end times e Statistics member 1 Average e Namespace AWS ElastiCache e StartTime 2013 07 05T00 00 00 EndTime 2013 07 06T00 00 00 e Period 60 e MeasureName CPUUtilization e Dimensions CacheClusterId mycachecluster CacheNodeId 0002 Example http monitoring amazonaws com SignatureVersion 4 Action GetMetricStatistics amp Version 2014 12 01 amp StartTime 2013 07 16T00 00 00 amp EndTime 2013 07 16T00 02 00 amp Period 60 amp Statistics member 1 Av
273. rite new or updated data e You have a large dataset that takes a long time to persist to disk thus requiring a large number of write operations The following diagram illustrates memory use when executing BGSAVE Memory use prior to a snapshot Memory for data Reserved available memory Memory use during a snapshot Memory for data Memory needed beyond available memory Memory use during a snapshot insufficient memory Memory for data For information on the performance impact of doing a backup see Performance Impact of Snapshots p 40 For more information on how Redis performs snapshots go to htip redis io in the Redis documentation For more information on regions and Availability Zones go to Regions and Availability Zones p 43 Avoiding Running Out of Memory When Executing BGSAVE Whenever BGSAVE is called you must have more memory available than will be consumed by write operations during the BGSAVE process to keep the process from failing Because the worst case scenario is that every Redis record is updated plus new records that cause additional write operations we recommend that you reserve at least half of the cluster s maxmemory value for overhead The maxmemory value indicates the memory available to you for data and operational overhead For maxmemory values by node instance type see Parameters for Redis p 48 To reserve memory for uses other than data set the Redis sp
274. rmation in CloudtTrail When CloudtTrail logging is enabled in your AWS account API calls made to ElastiCache actions are tracked in log files For example calls to the CreateCacheCluster DescribeCacheCluster and ModifyCacheCluster APIs generate entries in the CloudTrail log files All of the ElastiCache actions are logged For a full list of ElastiCache actions go to htip docs amazonaws cn AmazonElastiCache latest APIReference Each log file contains not only ElastiCache records but also other AWS service records CloudTrail determines when to create and write to a new log file based on a time period and file size Every log entry contains information about who generated the request The user identity information in the log helps you determine whether the request was made with root or IAM user credentials with temporary security credentials for a role or federated user or by another AWS service For more information go to the documentation for the userldentity field in the CloudTrail Event Reference You can store your log files in your bucket for as long as you want You can also define Amazon S3 lifecycle rules to archive or delete log files automatically By default your log files are encrypted using Amazon S3 server side encryption SSE If you want to take quick action upon log file delivery you can have CloudTrail publish Amazon SNS notifications when new log files are delivered For more information see Configuring Amazon SNS
275. rrent primary node even if you decide to reconfigure your replication group by promoting a read replica to the primary role AWS Management Console To determine endpoints and port numbers 1 Signin to the Amazon ElastiCache Management Console and click Cache Clusters 2 Click Replication Group and choose your replication group 3 Click the Node Groups tab All of the read replicas and the node group endpoint are displayed with fully qualified DNS names and port numbers for each API Version 2015 02 02 186 Amazon ElastiCache User Guide CLI CLI To determine cache node endpoints and port numbers e Use the command elasticache describe replication groups with the name of your replication group PROMPT gt elasticache describe replication groups my repgroup This command should produce output similar to the following REPLICATIONGROUP my repgroup My replication group available CLUSTERID my redis primary CLUSTERID my replica l NODEGROUP 0001 my repgroup f310xz ng 0001 cache amazonaws com 6379 available NODEGROUPMEMBER my redis primary 0001 my redis primary f310xz 0001 cache amazonaws com 6379 us west 2a primary NODEGROUPMEMBER my replica 1l 0001 my replica 1 310xz 0001 cache amazonaws com 6379 us west 2b replica API To determine cache node endpoints and port numbers e Call DescribeReplicationGroups with the following parame
276. rsion 2 8 19 p 88 e Redis Version 2 8 6 p 88 e Redis Version 2 6 13 p 88 Redis Version 2 8 19 Redis improvements added since version 2 8 6 include the following Support for HyperLogLog For more information go to Redis new data structure HyperLogLog The sorted set data type has now support for lexicographic range queries with the new commands ZRANGEBYLEX ZLEXCOUNT and ZREMRANGEBYLEX To prevent a primary node from sending stale data to replica nodes the master SYNC fails if a background save bgsave child process is aborted Redis Version 2 8 6 Redis improvements added since version 2 6 13 include the following Improved resiliency and fault tolerance for read replicas e Support for partial resynchronization Support for user defined minimum number of read replicas that must be available at all times e Full support for pub sub notifying clients of events on the server e Automatic detection of a primary node failure and failover of your primary node to a secondary node Redis Version 2 6 13 Redis version 2 6 13 was the initial version of Redis supported by Amazon ElastiCache API Version 2015 02 02 88 Amazon ElastiCache User Guide Managing Clusters Managing Clusters This section covers operations on clusters Topics Creating a Cluster p 89 Adding or Removing Nodes p 96 Modifying a Cluster p 104 Managing Reserved Nodes p 106 Using A
277. s checked box is checked the console expands so you can specify the number of days a backup is to be retained before deleting and optionally specify when you want the automatic backups scheduled If you do not specify the schedule automatic backups are created on a schedule set by ElastiCache In the Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window The screen expands so you can specify the day of the week to start maintenance the UTC time to start maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default We recommend specifying a maintenance window so that downtime for maintenance will have the least impact upon your business b Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see http aws amazon com sns Click Next Step 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings API Version 2015 02 02 95 Amazon ElastiCache User Guide Adding or Removin
278. s with the following parameters to view all ElastiCache events for the past 24 hours PROMPT gt elasticache describ vents duration 1440 API To view all ElastiCache instance events for the past 24 hours e Call DescribeEvents with the following parameters e Duration 1440 API Version 2015 02 02 182 Amazon ElastiCache User Guide API Example https elasticache amazonaws com Action DescribeEvents amp Duration 1440 amp MaxRecords 100 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 183 Amazon ElastiCache User Guide Restricted Commands Configuring ElastiCache Clients Topics Restricted Commands p 184 Cache Node Endpoints and Port Numbers p 184 Connecting to Nodes in a Replication Group p 186 e DNS Names and Underlying IP p 188 An ElastiCache cluster is protocol compliant with Memcached or Redis depending on which cache engine was selected when the cluster was created The code applications and most popular tools that you use today with your existing Memcached or Resdis environments will work seamlessly with t
279. scribeEngineDefaultParameters in the Amazon ElastiCache API Reference To manage parameter groups you can use the following API actions CreateCacheParameterGroup Creates a parameter group DescribeCacheParameterGroups Returns information about parameter groups associated with your AWS account DescribeCacheParameters Returns information about parameters that are part of a parameter group ModifyCacheParameterGroup Updates the parameters in a parameter group DeleteCacheParameter Deletes a named parameter group ResetCacheParameterGroup Resets individual parameters or all parameters in a parameter group to their default values You can change the parameter group associated with a cluster at any time using the ModifyCacheCluster action The changes will not be applied to the running cluster until each node in the cluster is rebooted To reboot one or more nodes in a cluster you can call the Reboot CacheCluster action For more information on working with parameter groups see Managing Cache Parameter Groups p 155 Parameters for Memcached Topics Memcached 1 4 14 Added Parameters p 44 Memcached 1 4 5 Parameters p 45 e Understanding and Tuning Memcached Connection Overhead p 46 Node Type Specific Parameters for Memcached p 47 If you do not specify a parameter group for your Memcached cluster then a default parameter group default memcached1 4 will be used You cannot change
280. see http docs aws amazon com AmazonElastiCache latest CommandLineReference CLIReference cmd CreateCacheCluster html and http docs aws amazon com AmazonElastiCache latest CommandLineReference CLIReference cmd CreateReplicationGroup html Using the ElastiCache CLI to Enable Redis Multi AZ for an Existing Replication Group The following code example uses the ElastiCache CLI to enable Multi AZ for the replication group myReplGroup SPROMPT gt elasticache modify replication group myReplGroup apply immediately automatic failover enabled tru For more information see http docs aws amazon com AmazonElastiCache latest CommandLineReference CLIReference cmd ModifyReplicationGroup html Enabling Redis Multi AZ using the ElastiCache API You can use the ElastiCache API to enable Redis Multi AZ for a new or existing replication group API Version 2015 02 02 36 Amazon ElastiCache User Guide Enabling Redis Multi AZ Using the ElastiCache API to Enable Redis Multi AZ for a New Replication Group The following example creates the Multi AZ enabled replication group myRep1Group using the active Redis cluster myPrimaryCluster as its primary cluster It then adds the read replica myReplicaCluster00 to the replication group 1 Create the replication group specifying the primary cache cluster and enabling Multi AZ as shown in the following example that creates the replication group myRep1Group enables Multi AZ and
281. set when you close the command window You might want to set them permanently Consult the documentation for your version of Windows for more information Note Paths that contain a space must be wrapped in double quotes for example C Program Files Java API Version 2015 02 02 83 Amazon ElastiCache User Guide Providing Credentials for the Tools Providing Credentials for the Tools The command line tools need the AWS Access Key and Secret Access Key provided with your AWS account You can get them using the command line or from a credential file located on your local system The deployment includes a template file AWS_ELASTICACHE_HOME credential file path template that you need to edit with your information Following are the contents of the template file AWSAccessKeyld lt Write your AWS access ID gt AWSSecretKey lt Write your AWS secret key gt Important On UNIX limit permissions to the owner of the credential file chmod 600 lt the file created above gt With the credentials file setup you ll need to set the AWS_CREDENTIAL_FILE environment variable so that the ElastiCache tools can find your information To set the AWS_CREDENTIAL_FILE environment variable 1 Set the environment variable On Linux and UNIX update the variable using the following command export AWS_CREDENTIAL_FILE lt the file created above gt On Windows set the var
282. snapshot use the elasticache copy snapshot command The following example makes a copy of an automatic snapshot PROMPT gt elasticache copy snapshot automatic my redis primary 2014 03 27 03 15 my snapshot copy API To copy a snapshot use the CopySnapshot action with the following parameters e SourceSnapshotName e TargetSnapshotName The following example makes a copy of an automatic snapshot Example https elasticache us west 2 amazonaws com Action CopySnapshot amp TargetSnapshotName my snapshot copy amp SourceSnapshotName automatic my redis primary 2014 03 27 03 15 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20141201T220302Z amp X Amz Algorithm AWS4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Restoring a Snapshot to a New Cluster To restore your data from a snapshot ElastiCache must first create a new cluster and then copy the data from the snapshot into the new cluster s Redis cache When this process is complete your applications can access the data in the new cluster The following procedures show you how to restore a snapshot to a new cluster API Version 2015 02 02 149 Amazon ElastiCache User Guide Restoring a Snapshot to a New Cluster AWS Manageme
283. stance Type 3 Configure Instance 4 Add Storage 5 Tag instance 6 Configure Security Group 7 Review Step 3 Configure Instance Details Configure the instance to suit your requirements You can launch multiple instances from the same AMI request Spot Instances to take advantage Pricing assign an access management role to the instance and more Number of instances j Purchasing option lt i Request Spot instances Network i vpe d3a77cb6 10 0 0 0 16 Create new VPC Subnet lt i subnet 58f5e63a10 0 0 0 24 sa east La 3 Create new subnet 250 IP Addresses available Public iP Automatically assign a public IP address to your instances When the settings are as you want them click Next Add Storage 4 On the Add Storage Page click Next Tag Instance 5 On the Tag Instance page type a name for your Amazon EC2 instance and then click Next Configure Security Group 6 Onthe Configure Security Group page click Select an existing security group Choose AMI 2 Choose instance Type 3 Contigure Instance 4 Add Storage 5 Tag instance 6 Configure Securty Group 7 Amoa Step 6 Configure Security Group A security group is a set of firewall rules that contro the traffic for your instance On this page you can add rules to allow specific traffic t example if you want to set up a web server and allow Internet traffic to reach your instance add rules that allow unrestricted access to th You can create a new security group
284. stiCache Management Console You can use the ElastiCache management console to remove tags from an existing ElastiCache resource To remove a tag from an ElastiCache resource using the ElastiCache management console 1 6 Sign in to the AWS Management Console and open the Amazon ElastiCache console at htips console aws amazon com elasticache Depending what ElastiCache resource you want to remove a tag from click either Clusters or Snapshots Select the ElastiCache resource you want to remove a tag from Click Manage Tags at the top of the screen For each tag that you want to remove from this resource click the Delete check box to the right of the tag Manage Tags x Apply tags to your resources to help organize and identify them Atag consists of a case sensitive key value pair For example you could define a tag with key Name and value Webserver Learn More about tagging your AWS resources Applied Tags Key Value Delete Serice ElastCache Region AP Singapore CostCenter Add Tags Key Value Cancel Apply Changes When finished click Apply Changes to keep your changes or Cancel to discard your changes AWS CLI You can use the AWS CLI to remove tags from an existing ElastiCache resource by using the remove tags from resource command The following code uses the AWS CLI to remove the tags with the keys Service and Region from the resource myCluster in the us west 2 region API Version 2015 02 02 72
285. t hashing is turned off by the Memcached PHP library To turn consistent hashing on in your php ini file set the memcached hash_strategy parameter to consistent You can set the memcached hash_function to the hash function you prefer The default is crc32 For more information go to the run time configuration documentation for Memcached PHP at hitp php net manual en memcache ini php Note specifically the memcached hash_strategy and memcached hash_function parameters Consistent Hashing Using NET The ElastiCache Memcached NET client is a wrapper around Enyim Memcached By default consistent hashing is turned on by the Enyim Memcached client For more information go to the memcached 1locator documentation at htips github com enyim EnyimMemcached wiki MemcachedClient Configuration user content memcachedlocator API Version 2015 02 02 25 Amazon ElastiCache User Guide Nodes ElastiCache Terminology and Concepts This chapter introduces you to ElastiCache terminology and concepts Many of the concepts introduced in this chapter are explored in greater depth in later chapters Topics Nodes p 26 Replication Groups and Read Replicas Redis p 30 Multi AZ with Redis Replication Groups p 32 Backup and Restore for Redis Clusters p 38 Clusters p 41 Regions and Availability Zones p 43 Parameter Groups p 43 Subnet Groups p 59 Security Groups p 59 ElastiCache and Amazon Virtual Priva
286. t to a Cluster Node p 17 Step 5 Delete Your Cache Cluster p 21 Where Do Go From Here p 21 Step 1 Before You Begin To use ElastiCache you need an AWS account If you don t already have one you ll be prompted to create one when you sign up You re not charged for any AWS services that you sign up for unless you use them To sign up for ElastiCache 1 Open http www amazonaws cn and then click Sign Up 2 Follow the on screen instructions Part of the sign up procedure involves receiving a phone call and entering a PIN using the phone keypad Step 2 Launch a Cluster After you have signed up for ElastiCache you can launch a cluster Amazon ElastiCache supports two engines Redis and Memcached To determine which engine will best suit your needs go to Selecting a Cache Engine and Version p 87 in this guide API Version 2015 02 02 8 Amazon ElastiCache User Guide Step 2 Launch a Memcached Cluster For more information on the Redis engine see http redis io For more information on the Memcached engine see hitp memcached org The cluster you re about to launch will be live and not running in a sandbox You will incur the standard ElastiCache usage fees for the instance until you delete it The total charges will be minimal typically less than a dollar if you complete the exercise described here in one sitting and delete your cluster when you are finished For more information about ElastiCache usag
287. tall the te net utility on your Amazon EC2 instance At the command prompt of your Amazon EC2 instance type the following command At the confirmation prompt type y sudo yum install telnet Loaded plugins priorities security update motd upgrade helper Setting up Install Process Resolving Dependencies gt Running transaction check output omitted API Version 2015 02 02 18 Amazon ElastiCache User Guide Step 4 Connect to a Redis Cluster Total download size 63 k Installed size 109 k Is this ok y N y Downloading Packages telnet 0 17 47 7 amzn1 x86_64 rpm 63 kB 00 00 output omitted Complete 3 At the command prompt of your Amazon EC2 instance type the following command substituting the endpoint of your node for the one shown in this example telnet mycachecluster eaogs8 0001 usw2 cache amazonaws com 11211 You will see output similar to the following Trying 128 0 0 1 Connected to mycachecluster eaogs8 0001 usw2 cache amazonaws com Escape character is gt You are now connected to a node and you can run Memcached commands The following is an example set a0 05 Set key a with no expiration and 5 byte value hello Set value as hello STORED get a Get value for key a VALUE a 0 5 hello END get b Get value for key b results in miss END gt Step 4 Conne
288. te Cloud p 60 Cache Engine Version Management p 63 Nodes A node is the smallest building block of an ElastiCache deployment It is a fixed size chunk of secure network attached RAM Each cache node runs an instance of either Memcached or Redis depending on what was selected when the cluster was created Each cache node has its own Domain Name Service DNS name and port Multiple types of cache nodes are supported each with varying amounts of associated memory Topics Node Considerations for Memcached p 27 Node Considerations for Redis p 29 e Reserved Nodes p 29 API Version 2015 02 02 26 Amazon ElastiCache User Guide Node Considerations for Memcached Note For a complete list of cache node types and specifications go to Amazon ElastiCache Product Features and Details and either Cache Node Type Specific Parameters for Memcached or Cache Node Type Specific Parameters for Redis Node Considerations for Memcached With a cluster running Memcached you can Easily select and change the amount of memory and compute capacity available in your cluster e Easily select the Availability Zone or zones for your cache nodes Node Size Considerations The total memory capacity of your cluster is calculated by multiplying the number of cache nodes in the cluster by the capacity of each node The capacity of each cache node is based on the cache node type The number of cache nodes in the cluster is a key factor
289. ter ReplicationGroupId the name of your replication group Example https elasticache us west 2 amazonaws com Action DescribeCacheClusters amp ReplicationGroupId repgroup0l amp Version 2014 09 30 SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20140421T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20140421T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 201404217T2203022 amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt API Version 2015 02 02 187 Amazon ElastiCache User Guide DNS Names and Underlying IP DNS Names and Underlying IP Memcached and Redis clients maintain a server list containing the addresses and ports of the servers holding the cache data When using ElastiCache the DescribeCacheClusters API or the elasticache describe cache clusters command line utility returns a fully qualified DNS entry and port number that can be used for the server list Important It is important that client applications are configured to frequently resolve DNS names of cache nodes when they attempt to connect to a cache node endpoint ElastiCache will ensure that the DNS name of a cache node is unchanged when cache nodes are recovered in case of failure however the underlying IP address of the cache node can change Most Memcached and Redis client libraries support persistent cache node connectio
290. terGroupFamily gt lt Description gt My new parameter group lt Description gt lt CacheParameterGroup gt lt CreateCacheParameterGroupResult gt lt ResponseMetadata gt lt Request Id gt d8465952 af48 11le0 8d36 85 9edcabf4b8 lt RequestId gt lt ResponseMetadata gt lt CreateCacheParameterGroupResponse gt API Version 2015 02 02 156 Amazon ElastiCache User Guide Listing Available Cache Parameter Groups Listing Available Cache Parameter Groups You can see which cache parameter groups you ve created for your AWS account by listing them The following procedures show you how to list all available cache parameter groups Note The default memcached1 4 parameter group family is automatically created the first time you create a cache cluster without specifying a custom cache parameter group AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Click Cache Parameter Groups in the navigation list on the left side of the window The available cache parameter groups appears in the Cache Parameter Groups list CLI Use the command elasticache describ parameter groups for your AWS account cache parameter groups to list all available cache PROMPT gt elasticache describe cache parameter groups This command should produce output similar to the following CACHEPARAME
291. tes from an AOF file thereby recovering the data lost due to the restart or crash Warning AOF cannot protect against all failure scenarios For example if a node fails due to a hardware fault in an underlying physical server ElastiCache will provision a new node on a different server In this case the AOF file will no longer be available and cannot be used to recover the data Thus Redis will restart with a cold cache Enabling Redis Multi AZ as a Better Approach to Fault Tolerance If you are enabling AOF to protect against data loss consider using a replication group with Multi AZ enabled instead of AOF When using a Redis replication group if a replica fails it is automatically replaced and synchronized with the primary cluster If Multi AZ is enabled on a Redis replication group and the primary fails it fails over to a read replica This functionality is much faster than rebuilding the primary from an AOF file For greater reliability and faster recovery we recommend that you create a replication group with one or more read replicas in different availability zones and enable Multi AZ instead of using AOF Because there is no need for AOF in this scenario ElastiCache disables AOF on Multi AZ replication groups For more information see the following topics e Append Only Files AOF p 58 e Replication Groups and Read Replicas Redis p 30 e Multi AZ with Redis Replication Groups p 32 Configuring Your ElastiCache Clie
292. th auto failover support for Redis replication groups ElastiCache added support for the EU Frankfurt eu central 1 region ElastiCache added support for Multi AZ with automatic January 19 2015 October 24 2014 failover from the primary node to a read replica in a Redis replication group ElastiCache monitors the health of the replication group If the primary fails ElastiCache automat ically promotes a replica to primary then replaces the replica For more information see Multi AZ with Redis Replication Groups p 32 AWS CloudTrail logging of API calls supported New instance sizes supported Flexible node place ment supported for Memcached New instance sizes supported PHP auto discovery ElastiCache added support for using AWS CloudTrail to September 15 2014 log all ElastiCache API calls For more information see Logging Amazon ElastiCache API Calls Using AWS CloudTrail p 196 ElastiCache added support for additional General Purpose T2 instances September 11 2014 For more information see Parameter Groups p 43 ElastiCache added support for creating Memcached nodes July 23 2014 across multiple Availability Zones For more information see Step 2 Launch a Cluster p 8 and Node Considerations for Memcached p 27 ElastiCache added support for additional General Purpose July 1 2014 M3 instances and Memory Optimized R3 instances For more
293. the Multi AZ enabled replication group myRep1Group using the active Redis cluster myPrimaryCluster as its primary cluster It then adds the read replica myReplicaCluster00 to the replication group 1 Create the replication group specifying the primary cache cluster and enabling Multi AZ by using a command like the following SPROMPT gt elasticache create replication group myReplGroup d cli demo p myPrimaryCluster a true 2 Add a replica Redis cache cluster to the replication group by using a command like the following You can perform this step up to five times changing only the name of the cluster SPROMPT gt elasticache create cache cluster myReplicaCluster00 rg myReplGroup e redis c cache ml small n 1 If you don t have an active Redis cache cluster to use as the primary cluster you can create the replication group and its associated cache clusters with a single command The following example creates the Multi AZ enabled replication group my rg with 3 cache clusters the primary cluster my rg001 and two replicas my rg002 and my rg003 SPROMPT gt elasticache create replication group my rg d My replication group n 3 redis c cache m3 large a true When you create the clusters and replication group as shown in this example the names of the clusters are created by adding a three digit sequential number starting at 001 to the end of the replication group s names For more information
294. the following command At the confirmation prompt type y sudo yum install telnet Loaded plugins priorities security update motd upgrade helper Setting up Install Process Resolving Dependencies gt Running transaction check output omitted API Version 2015 02 02 169 Amazon ElastiCache User Guide Connecting to a Cache Cluster Running in an Amazon VPC Total download size 63 k Installed size 109 k Is this ok y N y Downloading Packages telnet 0 17 47 7 amzn1 x86_64 rpm 63 kB 00 00 output omitted Complete Go to the ElastiCache console at httos console www amazonaws cn elasticache and obtain the endpoint for one of the nodes in your cache cluster Use telnet to connect to your cache node endpoint over port 11211 Replace the hostname shown below with the hostname of your cache node telnet my cache cluster 7wufxa 0001 usel cache amazonaws com 11211 You are now connected to the cache engine and can issue commands In this example you will add a data item to the cache and then get it immediately afterward Finally you ll disconnect from the cache node To store a key and a value type the following two lines add mykey 0 3600 28 This is the value for my key The cache engine responds with the following STORED To retrieve the value for mykey type the following get mykey The cache engine responds with the following
295. the new cache node endpoints Before moving on to the next step be sure the Memcached nodes are fully created and available 2 Modify your cluster by removing the nodes you no longer want in the original Availability Zone In your request do the following Set NumCacheNodes CLI num cache nodes to the number of active cache nodes you want after this modification is applied e Set CacheNodeIdsToRemove CLI nodes to remove to a list of the cache nodes you want to remove from the cluster The number of cache node IDs listed must equal the number of currently active nodes minus the value in NumCacheNodes e Optional Set ApplyImmediately CLI apply immediately to true If you don t set ApplyImmediately CLI apply immediately to true the node deletions will take place at your next maintenance window API Version 2015 02 02 28 Amazon ElastiCache User Guide Node Considerations for Redis For information about how to create or modify a Memcached cluster see Managing Clusters For more information about using the command line interface CLI and API see the following topics Using the CLI to create a new cluster elasticache create cache cluster e Using the CLI to modify an existing cluster elasticache modify cache cluster Using the API to create a new cluster CreateCacheCluster e Using the API to modify an existing cluster ModifyCacheCluster For more information about regions and Avai
296. the primary cluster The failover process usually takes 2 to 3 minutes after which you can again write to the read write primary cluster When Multi AZ is enabled ElastiCache continually monitors the state of the primary cluster If the primary cluster fails one of the following actions is performed Whenever ElastiCache detects a failed primary node and fails over to a secondary node the following events are reported and may be observed using any of the methods described at Viewing ElastiCache Events p 182 e Failover from master node lt name gt to replica node lt name gt completed e Recovering cache nodes lt name gt e Finished recovery for cache nodes lt name gt Multi AZ if Only the Primary Node Fails If only the primary node fails ElastiCache performs the following process i ElastiCache takes the failed primary cluster offline 2 ElastiCache promotes one of the replicas to the primary role Write operations can resume as soon as the promotion process is complete typically 3 to 4 minutes You don t need to change the endpoint for write operations because ElastiCache propagates the DNS address of the promoted replica 3 ElastiCache creates and provisions a replacement replica API Version 2015 02 02 33 Amazon ElastiCache User Guide Failure Scenarios and Multi AZ Responses If possible the replacement replica is created in the Availability Zone where the failed primary was so that the distribution
297. this key type the key s value in the text box in the Value column at the key name s right To add multiple tags to this resource repeat the preceding procedure for each tag you want to add If you enter a tag key you don t want to add to this resource click the X to the right of the tag to delete it Manage Tags x Apply tags to your resources to help organize and identify them Atag consists of a case sensitive key value pair For example you could define a tag with key Name and value Webserver Learn More about tagging your AWS resources Applied Tags Key Value Delete Service ElastiCache Add Tags Key Region AP Toyko Cost Center Empty value Add key aT i ae i Cancel Apply Changes When finished click Apply Changes to keep your changes or Cancel to discard your changes AWS CLI You can use the AWS CLI to add tags to an existing ElastiCache resource by using the add tags to resource command The following code uses the AWS CLI to add the keys Service and Region with the values elasticache and us west 2 respectively to the resource myCluster in the us west 2 region The resource name parameter value is in the format of an ARN arn aws elasticache lt region gt lt customer id gt lt resource type gt lt resource name gt API Version 2015 02 02 67 Amazon ElastiCache User Guide ElastiCache API PROMPT gt aws elasticache add tags to resource resource name arn aws elastic ach
298. three nodes would be represented as follows API Version 2015 02 02 124 Amazon ElastiCache User Guide Actions You Can Take When a Node is Scheduled for Replacement configversion r n hostname ip address port hostname ip address port hostname ip address port r n Each node is shown with both the CNAME and the private IP address The CNAME will always be present if the private IP address is not available it will not be shown however the pipe characters will still be printed Example Here is an example of the payload returned when you query the configuration information CONFIG cluster 0 147 r n 12 r n myCluster pc4ldq 0001 usel cache amazonaws com 10 82 235 120 11211 myc luster pc4ldq 0002 usel cache amazonaws com 10 80 249 27 11211 n r n END r n Note The second line indicates that the configuration information has been modified twelve times so far In the third line the list of nodes is in alphabetical order by hostname This ordering might be in a different sequence from what you are currently using in your client application Actions You Can Take When a Node is Scheduled for Replacement Memcached Do nothing Doing nothing will result in the node being replaced as scheduled ElastiCache will automatically replace the node with a new node that will initially be empty Manually replace the node 1 Delete the node scheduled for replacement For instructions go to Removing Nodes from a C
299. ting a Read Replica to the Primary Role p 134 In your application replace the old cluster s endpoint with the new cluster s endpoint Delete the cluster scheduled for replacement For instructions go to Deleting a Cache Cluster p 114 API Version 2015 02 02 126 Amazon ElastiCache User Guide Managing Replication Groups Managing Replication Groups This section covers creating and managing replication groups Topics Creating a Redis Replication Group p 127 Adding a Read Replica To a Replication Group p 133 Promoting a Read Replica to the Primary Role p 134 Modifying an Existing Redis Replication Group p 135 Deleting a Read Replica p 136 Deleting a Replication Group p 137 Note At this time replication groups are supported only for cache clusters that are running Redis Creating a Redis Replication Group A Redis replication group is comprised of one primary read write cluster and from one to five secondary read only clusters All write operations are performed on the primary cluster New or changed data is asynchronously propagated from the primary to the read replicas Because updates to the secondary clusters are asynchronous there can be some latency between when something is written to the primary and when it is available from a secondary Read operations can be performed on any of the clusters By default Amazon ElastiCache automatically replaces any failed read replicas in a Redis replicatio
300. to disable Amazon SNS notifications AWS Management Console To disable Amazon SNS notifications using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe Cache Clusters list click the Modify link next to the cluster to which you want to disable an Amazon SNS topic ARN The Modify Cache Cluster window appears 3 In the Notification Topic Status list click inactive 4 Select the Apply Immediately check box 5 Click the Yes Modify button CLI To disable Amazon SNS notifications use the command elasticache modify cache cluster with the following parameters PROMPT gt elasticache modify cache cluster my cache cluster ts inactive This command produces output similar to the following CACHECLUSTER my cache cluster 2013 07 26T01 21 46 607Z cache ml large mem cached available 3 us west 2c 1 4 5 SECGROUP default active PARAMGRP default memcached1l 4 in sync API Version 2015 02 02 113 Amazon ElastiCache User Guide Deleting a Cache Cluster NOTIFICATION arn aws sns us west 2 565419523791 ElastiCacheNotifications inactive API To disable Amazon SNS notifications call the Modi fyCacheCluster action with the following parameters e CacheClusterId my cache cluster NotificationTopicStatus inactive This call returns output similar to the following
301. tomatic backups of this cluster You can also perform manual backups if you so choose When this checked box is checked the console expands so you can specify the number of days a backup is to be retained before deleting and optionally specify when you want the automatic backups scheduled If you do not specify the schedule automatic backups are created on a schedule set by ElastiCache In the Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window The screen expands so you can specify the day of the week to start maintenance the UTC time to start maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default We recommend specifying a maintenance window so that downtime for maintenance will have the least impact upon your business b Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see http aws amazon com sns Click Next API Version 2015 02 02 14 Amazon ElastiCache User Guide Step 3 Authorize Access Ste
302. tomatically identify all of the nodes in a cache cluster and to initiate and maintain connections to all of these nodes With Auto Discovery your application does not need to manually connect to individual cache nodes instead your application connects to a configuration endpoint The configuration endpoint DNS entry contains the CNAME entries for each of the cache node endpoints thus by connecting to the configuration endpoint you application immediately knows about all of the nodes in the cluster and can connect to all of them You do not need to hardcode the individual cache node endpoints in your application All of the cache nodes in the cluster maintain a list of metadata about all of the other nodes This metadata is updated whenever nodes are added or removed from the cluster Auto Discovery offers the following benefits When you increase the number of nodes in a cache cluster the new nodes register themselves with the configuration endpoint and with all of the other nodes When you remove nodes from the cache cluster the departing nodes deregister themselves In both cases all of the other nodes in the cluster are updated with the latest cache node metadata e Cache node failures are automatically detected failed nodes are automatically marked as unavailable e A client program only needs to connect to the configuration endpoint After that the Auto Discovery library connects asynchronously to all of the other nodes in the c
303. tput similar to the following CACHECLUSTER my cache cluster 2013 07 06T23 34 09 756Z cache ml large memcached modifying 3 us west 2b 1 4 5 5 SECGROUP default active PARAMGRP default memcachedl 4 in sync API To remove nodes using the API call the ModifyCacheCluster action with the cache cluster ID anda list of nodes to remove as shown e CacheClusterId my cache cluster e NumCacheNodes 3 e CacheClusterNodelIdsToRemove member 1 0004 e CacheClusterNodelIdsToRemove member 2 0005 e ApplyImmediately true This call produces output like the following API Version 2015 02 02 102 Amazon ElastiCache User Guide Adding or Removing Nodes Example https elasticache us west 2 amazonaws com Action ModifyCacheCluster amp CacheClusterId my cache cluster ApplyImmediately true amp CacheClusterNodelIdsToRemove member 1 0004 amp CacheClusterNodelIdsToRemove member 2 0005 amp NumCacheNodes 3 amp Version 2014 12 01 amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T220302Z amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T220302Z amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Canceling Pending Add or Delete Node Operations AWS Management Console If you elected to not apply a change imm
304. ty to other Availability Zones in the same region Important Each region is completely independent Any ElastiCache activity you initiate for example creating clusters runs only in your current default region The default region can be changed by setting the EC2_REGION environment variable or be overridden by using the ur1 parameter with the command line interface For more information see Common Options for API Tools To create or work with a cluster in a specific region use the corresponding regional service endpoint For a listing of ElastiCache endpoints go to the Regions and Endpoints section of the Amazon Web Services General Reference Locating Your Redis Read Replicas and Memcached Nodes Amazon ElastiCache supports specifying in which Availability Zone you create your clusters If your Redis replication group will have multiple clusters or your Memcached cache cluster will have multiple nodes you have the option to locate all the clusters Redis or nodes Memcached in a single Availability Zone or locate them across different Availability Zones By locating the clusters or nodes in different Availability Zones you eliminate the chance that a failure such as a power outage in one Availability Zone will cause your entire system to fail Testing has demonstrated that there is no significant latency difference between locating all nodes in one Availability Zone or spreading them across multiple Availability Zones To specif
305. ubnet Group A cache subnet group is a collection of subnets that you may want to designate for your cache clusters in an Amazon VPC When launching a cache cluster in an Amazon VPC you will need to select a cache subnet group ElastiCache then uses that cache subnet group to assign IP addresses within that subnet to each cache node in the cluster In this example you will create a cache subnet group and add the private subnets from your Amazon VPC AWS Management Console To create a cache subnet group 1 w Sign in to the AWS Management Console and open the ElastiCache console at https console www amazonaws cn elasticache In the navigation list click Cache Subnet Groups Click Create Cache Subnet Group In the Create Cache Subnet Group wizard do the following When all the settings are as you want them click Yes Create Create Cache Subnet Group x To create a new Subnet Group give it a name description and select an existing VPC below Once you select an existing VPC you will be able to add subnets related to that VPC Name my cache subnet gre Description Testing e VPC ID vpc d3a77cb6 Add Subnet s to this Subnet Group You may add subnets one at a time below or add all the subnets related to this VPC You may make additions edits after this group is created Availability Zone sa east la Availability Zone Subnet ID CIDR Block Action Subnet ID subnet 5bf5 639 sa east 1a subnet 5bf5
306. uctions go to Promoting a Read Replica to the Primary Role p 134 Delete the cluster that is scheduled for replacement the old primary For instructions go to Deleting a Cache Cluster p 114 Add a new replica to replace the one you just deleted For instructions go to Adding a Read Replica To a Replication Group p 133 In your application replace the old cluster s endpoint with the new cluster s endpoint e Replace a stand alone cluster If the cluster is not a member of a replication group you have two options to replace a stand alone cluster Option 1 Replace the cluster using backup and restore Ie 2 3 4 Create a snapshot of the cluster For instructions go to Creating a Manual Snapshot p 146 Create a new cluster seeding it from the snapshot For instructions go to Restoring a Snapshot to a New Cluster p 149 In your application replace the old cluster s endpoint with the new cluster s endpoint Delete the cluster scheduled for replacement For instructions go to Deleting a Cache Cluster p 114 Option 2 Replace the cluster using replication 1 Create a replication group with the cluster scheduled for replacement as the primary For instructions go to Creating a Redis Replication Group p 127 Add a read replica to the replication group For instructions go to Adding a Read Replica To a Replication Group p 133 Promote the read replica to primary For instructions go to Promo
307. uld produce output similar to the following API Version 2015 02 02 155 Amazon ElastiCache User Guide Creating a Cache Parameter Group CACHEPARAMETERGROUP mycacheparametergroup memcachedl1 4 My new parameter group API Call createCacheParameterGroup with the following parameters CacheParameterGroupName myCacheparamgroup Description My new parameter group Example https elasticache us west 2 amazonaws com Action CreateCacheParameterGroup amp Description My 20new S20parameter 20group amp CacheParameterGroupFamily memcachedl1 4 amp CacheParameterGroupName myCacheParameterGroup amp Version 2014 12 01 amp Action CreateCacheParameterGroup amp SignatureVersion 4 amp SignatureMet hod HmacSHA256 amp Timestamp 20141201T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20141201T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20141201T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt This command should return a response similar to the following lt CreateCacheParameterGroupResponse xmlns http elasticache amazon aws com doc 2013 06 15 gt lt CreateCacheParameterGroupResult gt lt CacheParameterGroup gt lt CacheParameterGroupName gt mycacheparametergroup lt CacheParameterGroupName gt lt CacheParameterGroupFamily gt memcached1 4 lt CacheParame
308. um memory usage is reached Valid values are volatile lru allkeys lru volatile random allkeys random volatile ttl noeviction For least recently used LRU and time to live TTL calculations this parameter represents the sample size of keys to check By default Redis chooses 3 keys and uses the one that was used least re cently Determines the amount of memory used for certain kinds of sets strings that are integers in radix 10 in the range of 64 bit signed integers Such sets with fewer than the specified number of entries are stored using a spe cial encoding that saves space API Version 2015 02 02 55 Amazon ElastiCache User Guide Parameters for Redis Name reserved memory slave allow chaining slowlog log slower than Default Type Modi fi able 0 integer Yes no string No 10000 integer Yes Description The amount of memory in bytes reserved for non cache usage By default the Redis cache will grow until it consumes the node s maxmemory see Node Type Specific Parameters for Re dis p 57 before it starts evicting items or rejecting writes based on the maxmemory policy Redis uses additional memory for fea tures such as snapshots read replicas and append onlly files AOF If these features are active when maxmemory is exhausted node performance will likely suffer due to excessive memory paging If you increase reserved memory you lower the memory allocate
309. urity p 5 and Managing Cache Security Groups p 175 2 Inthe Maintenance section of the Configure Advanced Settings page specify settings as shown following a Maintenance Window Select how you want the maintenance window selected Select Window Specify the day of the week to start maintenance the UTC time to start maintenance and the duration in hours of the maintenance window No Preference ElastiCache selects the maintenance window This setting is the default We recommend specifying a maintenance window so that downtime for maintenance will have the least impact upon your business Topic for SNS Notification From the list select an existing Amazon Simple Notification Service Amazon SNS topic or click Manual ARN input and type in the topic Amazon Resource Name ARN Amazon SNS allows you to push notifications to Internet connected smart devices The default is to disable notifications For more information see htip aws amazon com sns API Version 2015 02 02 91 Amazon ElastiCache User Guide Creating a Cluster 3 Click Next Step 4 Review and Launch Before you continue be sure you have completed Step 3 Configure Advanced Settings To review your settings and launch your cluster 1 Review all your settings to ensure each value is what you want 2 If you need to make changes click Previous to return to previous screens and make your changes otherwise click Launch Cache Cluster or Launc
310. uster You can monitor the progress of this operation by viewing the ElastiCache event messages To do this go to the ElastiCache console and click Cache Events You can also use the ElastiCache command line interface or API to obtain event messages For more information see Viewing ElastiCache Events p 182 API Version 2015 02 02 152 Amazon ElastiCache User Guide Deleting Snapshots Deleting Snapshots You can delete any of your snapshots automatic or manual at any time Once the delete process has begun it cannot be canceled AWS Management Console To delete a snapshot using the AWS Management Console 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 On the ElastiCache console dashboard click Snapshots 3 Inthe list of Cache Snapshot Identifiers click the one that you want to delete and then click Delete Snapshot 4 In the Delete Cache Snapshot confirmation dialog box click Yes Delete to delete the snapshot otherwise click Cancel CLI To delete a snapshot use the elasticache delete snapshot command The following example deletes the snapshot my manual snapshot PROMPT gt elasticache delete snapshot my manual snapshot Note The elasticache delete snapshot command will prompt you for confirmation Type y if you want to delete the snapshot API To delete a snapshot use the DeleteSnapshot action with the following
311. uster p 89 This section provides instructions and examples for creating and maintaining cache clusters You can perform these tasks from either the AWS Management Console or the ElastiCache command line interface CLI If you want to use the ElastiCache CLI these materials can help you get started Setting Up the ElastiCache Command Line Interface p 81 This section provides information on downloading the ElastiCache CLI getting the CLI working on your system and providing your AWS credentials Amazon ElastiCache Command Line Reference This is a separate document with all of the ElastiCache CLI commands including syntax and examples You can write application programs to leverage the ElastiCache API using a variety of popular programming languages Here are some resources API Version 2015 02 02 3 Amazon ElastiCache User Guide Data Model Tools for Amazon Web Services Amazon Web Services provides a number of software development kits SDKs with support for ElastiCache You can code against ElastiCache using Java NET PHP Ruby and other languages These SDKs can greatly simplify your application development by formatting your requests to ElastiCache parsing responses and providing retry logic and error handling Using the ElastiCache API p 189 If you don t want to use the AWS SDKs you can interact with ElastiCache directly using the Query API This section provides troubleshooting tips and in
312. uster with the Amazon Resource Name ARN of an Amazon SNS topic to receive notifications API Version 2015 02 02 111 Amazon ElastiCache User Guide Using Amazon SNS Notifications with ElastiCache Note This topic assumes that you ve signed up for Amazon SNS and have set up and subscribed to an Amazon SNS topic For information on how to do this see the Amazon Simple Notification Service Developer Guide Adding an Amazon SNS Topic The following procedures show you how to add an Amazon SNS topic for a cluster Note This process can also be used to modify the Amazon SNS topic AWS Management Console To add or modify an Amazon SNS topic for a cluster 1 Sign in to the AWS Management Console and open the ElastiCache console at https console amazonaws cn elasticache 2 Inthe Cache Clusters list click the Modify link next to the cluster to which you want to add an Amazon SNS topic ARN The Modify Cache Cluster window appears 3 In the Notification Topic ARN box enter the ARN of the Amazon SNS topic 4 Click the Apply Immediately check box 5 Click the Yes Modify button CLI To add or modify an Amazon SNS topic for a cluster use the command elasticache modify cache cluster with the following parameters PROMPT gt elasticache modify cache cluster my cache cluster t arn aws sns us west 2 565419523791 ElastiCacheNotifications This command produces output similar to the fol
313. usterId test memcached Ey responseElements engine memcached clientDownloadLandingPage https console aws amazon com elastic ache home client download cacheParameterGroup cacheParameterGroupName default memcached1l 4 cacheNodeldsToReboot Er parameterApplyStatus in sync br cacheClusterCreateTime Dec 1 2014 10 16 06 PM preferredAvailabilityZone Multiple numCacheNodes 2 cacheNodeType cache ml small cacheClusterStatus modifying autoMinorVersionUpgrade true preferredMaintenanceWindow thu 05 00 thu 06 00 cacheClusterId test memcached engineVersion 1 4 14 cacheSecurityGroups Status active cacheSecurityGroupName default l configurationEndpoint address test memcached example cfg uselprod cache amazonaws com port 211207 pendingModifiedValues numCacheNodes 3 hy requestID 807 4bc3 354c 11e4 9376 c1d979ba565a event ID e9163565 376f 4223 96e9 9fF50528da645 API Version 2015 02 02 199 Amazon ElastiCache User Guide About IAM Controlling ElastiCache Access with IAM Topics About IAM p 200 ElastiCache Security Groups and IAM p 201 ElastiCache Resources and IAM p 201 ElastiCache Actions and IAM p 201 ElastiCache Keys p 202 Example Policies for ElastiCache p 203 Failure to Retrieve Account Attributes p 204 El
314. vior is native to Redis and isn t unique to ElastiCache Multi AZ For more details regarding this Redis behavior go to http redis io topics replication e Multi AZ is supported on Redis version 2 8 6 and later e Multi AZ is not supported on t1 and t2 cache nodes Important Connecting an external Redis replica to an ElastiCache Redis replication group that is Multi AZ enabled is an unsupported configuration that can create issues that prevent ElastiCache from properly performing failover and recovery If you need to connect an external Redis replica to an ElastiCache replication group make sure that Multi AZ is disabled before you make the connection You can enable Multi AZ using the Amazon ElastiCache console API or command line interface CLI We recommend creating the primary node and read replicas in different Availability Zones to best protect yourself from data loss in the unlikely case of a complete Availability Zone failure Topics Failure Scenarios and Multi AZ Responses p 33 Enabling Redis Multi AZ p 35 Failure Scenarios and Multi AZ Responses ElastiCache detects and replaces a replication group s failed nodes by recreating and reprovisioning the failed node When Multi AZ is enabled for a replication group a failed primary cluster instead fails over to one of the existing replicas A replica is selected and automatically promoted to the primary role which is much faster than recreating and reprovisioning
315. wing code creates this symbolic link ed usr 1ib64 sudo ln libsas12 so 3 libsas12 so 2 To install on a Ubuntu Server 14 04 LTS AMI 64 bit and 32 bit 1 Launch an Ubuntu Linux instance either 64 bit or 32 bit and log into it 2 Install PHP dependencies sudo apt get update sudo apt get install gcc g php5 php pear 3 Download the correct php memcached package for your Amazon EC2 instance and PHP version For more information see Downloading the Installation Package p 206 4 Install php memcached The URI should be the download path for the installation package sudo pecl install lt package download path gt API Version 2015 02 02 208 Amazon ElastiCache User Guide Installation Steps for New Users Note This installation step installs the build artifact amazon elasticache cluster client so into the usr lib php5 20121212 directory Please verify the absolute path of the build artifact because it is needed by the next step If the previous command doesn t work you need to manually extract the PHP client artifact amazon elasticache cluster client so from the downloaded tgz file and copy it to the usr lib php5 20121212 directory tar xvf lt package download path gt cp amazon elasticache cluster client so usr 1lib php5 20121212 With root sudo permission add a new file named memcached ini inthe etc php5 cli conf d directory and insert exte
316. with e To launch this cluster in a VPC recommended select a VPC subnet group e To launch this cluster outside a VPC click Not in VPC The cluster will be launched in the AWS public cloud Availability Zones From the drop down list select how you want the availability zones for the nodes in this cluster determined No Preference ElastiCache will select the availability zone for your cluster s nodes All nodes are launched in the same availability zone Spread Nodes Across Zones ElastiCache will select the availability zones for your cluster s nodes The nodes will be distributed as evenly as practical across the availability zones that support your node type Specify Zones The console expands to list all the availability zones in your region that support this cluster s node type Behind each zone is a text box Type in the number of nodes you want launched in that availability zone Note The total of the values you type into these text boxes must equal then number of nodes you specified in the previous screen Cache Security Groups or VPC Security Groups Select the security groups for this cluster If you selected a VPC the list is of VPC security groups If you select Not in VPC the list is of cache security groups For more information about Amazon VPC security groups see htip docs aws amazon com AmazonVPC latest UserGuide VPC_SecurityGroups html For more information about ElastiCache security groups see Sec
317. xample https elasticache us west 2 amazonaws com Action DescribeCacheClusters amp ShowCacheNodeInfo tru amp Version 2014 09 30 amp SignatureVersion 4 amp SignatureMethod HmacSHA256 amp Timestamp 20140421T2203022 amp X Amz Algorithm AWS 4 HMAC SHA256 amp X Amz Date 20140421T2203022 amp X Amz SignedHeaders Host amp X Amz Expires 20140421T2203022Z amp X Amz Credential lt credential gt amp X Amz Signature lt signature gt Auto Discovery If your applications use Auto Discovery you only need to know the configuration endpoint for the cluster rather than the individual endpoints for each cache node For more information see Node Auto Discovery Memcached p 116 Note At this time Auto Discovery is only available for cache clusters running the Memcached engine Connecting to Nodes in a Replication Group Note At this time replication groups and read replicas are only supported for cache clusters running Redis For replication groups ElastiCache provides console CLI and API interfaces to obtain connection information for individual nodes For read only activity applications can connect to any node in the replication group However for write activity we recommend that your applications connect to the primary endpoint for the replication group instead of connecting directly to the primary node This will ensure that your applications can always find the cu
318. y an Availability Zone for your Memcached nodes create a Memcached cluster as you normally do On the Cluster Details page of the Launch Cluster wizard use the Preferred Zone list to specify an Availability Zone for this node To specify an Availability Zone for your Redis read replica you first create a replication group and then add from one to five read replicas to the replication group You can specify a different Availability Zone for each read replica For more information on creating a Redis read replica in an Availability Zone different from the primary Redis cache cluster see Creating a Redis Replication Group p 127 and Adding a Redis Cache Cluster to a Replication Group p 32 Parameter Groups With Amazon ElastiCache you can use parameter groups to control the runtime parameters of your nodes A parameter group represents a combination of specific values for each parameter that is passed to the cache engine software during startup These values determine how the cache engine processes on each node will behave at runtime The parameter values on a specific parameter group apply to all nodes that are associated with the group regardless of which cluster they belong to Topics Parameters for Memcached p 44 e Parameters for Redis p 48 API Version 2015 02 02 43 Amazon ElastiCache User Guide Parameters for Memcached For a list of supported parameters their default values and which ones can be modified see De
319. you launched your cluster into an Amazon VPC environment Before you continue determine whether you launched your cluster into EC2 VPC or EC2 Classic To determine whether you launched your cluster into EC2 VPC or EC2 Classic using the AWS Management Console 1 Sign in to the AWS Management Console and open the Amazon EC2 console at https console amazonaws cn ec2 2 Locate Supported Platforms in the upper right corner Under Supported Platforms you will see either only VPC or both EC2 and VPC Account Attributes Account Attributes APC rted Platforms Supported Platforms If you see only VPC continue at You Launched Your Cluster into EC2 VPC p 16 If you see both EC2 and VPC continue at You Launched Your Cluster into EC2 Classic p 17 For more information see Detecting Your Supported Platforms and Whether You Have a Default VPC To determine whether you launched your cluster into EC2 VPC or EC2 Classic using the AWS Command Line Interface CLI 1 Open a command window 2 At the command prompt run the following command aws ec2 describe account attributes If you see only VPC in the output continue at You Launched Your Cluster into EC2 VPC p 16 If you see both EC2 and VPC in the output continue at You Launched Your Cluster into EC2 Classic p 17 You Launched Your Cluster into EC2 VPC If you launched your cluster into an Amazon Virtual Private Cloud Amazon VPC you can connect to your E
320. zon VPC For an example of one way to connect to your new cache cluster running in the Amazon VPC continue to Connecting to a Cache Cluster Running in an Amazon VPC p 167 Connecting to a Cache Cluster Running in an Amazon VPC This example shows how to launch an Amazon EC2 instance in your Amazon VPC You can then log in to this instance and access the ElastiCache cluster that is running in the Amazon VPC AWS Management Console In this example you create an Amazon EC2 instance in your Amazon VPC You can use this Amazon EC2 instance to connect to cache nodes running in the Amazon VPC Note For information about using Amazon EC2 go to the Amazon EC2 Getting Started Guide in the Amazon EC2 documentation To create an Amazon EC2 instance in your Amazon VPC Sign in to the AWS Management Console and open the Amazon EC2 console at https console amazonaws cn ec2 In the console click Launch Instance and follow these steps 1 Onthe Choose an Amazon Machine Image AMI page choose the 64 bit Amazon Linux AMI and then click Select On the Choose an Instance Type page click Next Configure Instance Details 3 On the Configure Instance Details page make the following selections a Inthe Network list choose your Amazon VPC b Inthe Subnet list choose your public subnet API Version 2015 02 02 167 Amazon ElastiCache User Guide Connecting to a Cache Cluster Running in an Amazon VPC 1 Choose AMI 2 Choose in

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