Supported engines and versions - Amazon ElastiCache
Supported Valkey versionsSupported Redis OSS versionsRedis OSS versions end of life scheduleSupported Memcached versions

Supported engines and versions

ElastiCache serverless caches support ElastiCache version 7.2 for Valkey and above, ElastiCache version 1.6 for Memcached and above, and ElastiCache 7.0 for Redis OSS and above.

ElastiCache self-designed caches support ElastiCache version 7.2 for Valkey and above, ElastiCache version 1.4.5 for Memcached and above, and ElastiCache 4.0.10 for Redis OSS and above.

Supported Valkey versions

Supported Valkey versions below. Note that Valkey supports most features available in ElastiCache version 7.2 for Redis OSS by default.

ElastiCache (Valkey) version 8.0

Here are some of the new features introduced in Valkey 8.0 (compared to ElastiCache Valkey 7.2.6):

  • Memory efficiency improvements, allowing users to store up to 20% more data per node without any application changes.

  • Newly-introduced per-slot metrics infrastructure for self-designed caches, providing detailed visibility into the performance and resource usage of individual slots.

  • ElastiCache Serverless for Valkey 8.0 can double the supported requests per second (RPS) every 2-3 minutes, reaching 5M RPS per cache from zero in under 13 minutes, with consistent sub-millisecond p50 read latency.

For more information on Valkey, see Valkey

For more information on the Valkey 8 release, see Valkey 8 Release Notes

ElastiCache version 7.2.6 for Valkey

On October 10 2024, ElastiCache version 7.2.6 for Valkey was released. Here are some of the new features introduced in 7.2 (compared to ElastiCache version 7.1 for Redis OSS):

  • Performance and memory optimizations for various data types: memory optimization for list and set type keys, speed optimization for sorted sets commands, performance optimization for commands with multiple keys in cluster mode, pub/sub performance improvements, performance optimization for SCAN, SSCAN, HSCAN, ZSCAN commands and numerous other smaller optimizations.

  • New WITHSCORE option for ZRANK and ZREVRANK commands

  • CLIENT NO-TOUCH for clients to run commands without affecting LRU/LFU of keys.

  • New command CLUSTER MYSHARDID that returns the Shard ID of the node to logically group nodes in cluster mode based on replication.

For more information on Valkey, see Valkey

For more information on the ElastiCache version 7.2 for Valkey release, see Redis OSS 7.2.4 Release Notes (ElastiCache version 7.2 for Valkey includes all changes from ElastiCache version 7.1 for Redis OSS up to ElastiCache version 7.2.4 for Redis OSS). Valkey 7.2 release notes at Valkey on GitHub.

Supported Redis OSS versions

ElastiCache Serverless caches and self-designed caches support all Redis OSS versions 7.1 and before.

ElastiCache version 7.1 for Redis OSS (enhanced)

This release contains performance improvements which enable workloads to drive higher throughput and lower operation latencies. ElastiCache version 7.1 for Redis OSS introduces two main enhancements :

We extended the enhanced I/O threads functionality to also handle the presentation layer logic. By presentation layer, we mean the Enhanced I/O threads which are now not only reading client input, but also parsing the input into Redis OSS binary command format. This is then forwarded to the main thread for execution which provides performance gain. Improved Redis OSS memory access pattern. Execution steps from many data structure operations are interleaved, to ensure parallel memory access and reduced memory access latency. When running ElastiCache on Graviton3-based R7g.4xlarge or larger, customers can achieve over 1 million requests per second per node. With the performance improvements to ElastiCache for Redis OSS v7.1, customers can achieve up to 100% more throughput and 50% lower P99 latency relative to ElastiCache for Redis OSS v7.0. These enhancements are enabled on node sizes with at least 8 physical cores (2xlarge on Graviton, and 4xlarge on x86), regardless of the CPU type and require no client changes.

Note

ElastiCache v7.1 is compatible with Redis OSS v7.0.

ElastiCache version 7.0 for Redis OSS (enhanced)

ElastiCache for Redis OSS 7.0 adds a number of improvements and support for new functionality:

  • Functions: ElastiCache for Redis OSS 7 adds support for Redis OSS Functions, and provides a managed experience enabling developers to execute LUA scripts with application logic stored on the ElastiCache cluster, without requiring clients to re-send the scripts to the server with every connection.

  • ACL improvements: Valkey and Redis OSS 7 adds support for the next version of Access Control Lists (ACLs). Clients can now specify multiple sets of permissions on specific keys or keyspaces in Valkey and Redis OSS.

  • Sharded Pub/Sub: ElastiCache for Valkey and Redis OSS 7 adds support to run Pub/Sub functionality in a sharded way when running ElastiCache in Cluster Mode Enabled (CME). Pub/Sub capabilities enable publishers to issue messages to any number of subscribers on a channel. Channels are bound to a shard in the ElastiCache cluster, eliminating the need to propagate channel information across shards resulting in improved scalability.

  • Enhanced I/O multiplexing: ElastiCache for Valkey and Redis OSS 7 introduces enhanced I/O multiplexing, which delivers increased throughput and reduced latency for high-throughput workloads that have many concurrent client connections to an ElastiCache cluster. For example, when using a cluster of r6g.xlarge nodes and running 5200 concurrent clients, you can achieve up to 72% increased throughput (read and write operations per second) and up to 71% decreaseed P99 latency, compared with ElastiCache version 6 for Redis OSS.

For more information on Valkey, see Valkey. For more information on the Redis OSS 7.0 release, see Redis OSS 7.0 Release Notes at Redis OSS on GitHub.

ElastiCache version 6.2 for Redis OSS (enhanced)

ElastiCache for Redis OSS 6.2 includes performance improvements for TLS-enabled clusters using x86 node types with 8 vCPUs or more or Graviton2 node types with 4 vCPUs or more. These enhancements improve throughput and reduce client connection establishment time by offloading encryption to other vCPUs. With Redis OSS 6.2, you can also manage access to Pub/Sub channels with Access Control List (ACL) rules.

With this version, we also introduce support for data tiering on cluster nodes containing locally attached NVMe SSD. For more information, see Data tiering in ElastiCache.

Redis OSS engine version 6.2.6 also introduces support for native JavaScript Object Notation (JSON) format, a simple, schemaless way to encode complex datasets inside Redis OSS clusters. With JSON support, you can leverage the performance and Redis OSS APIs for applications that operate over JSON. For more information, see Getting started with JSON. Also included are JSON-related metrics, JsonBasedCmds and JsonBasedCmdsLatency, that are incorporated into CloudWatch to monitor the usage of this datatype. For more information, see Metrics for Valkey and Redis OSS.

You specify the engine version by using 6.2. ElastiCache will automatically invoke the preferred patch version of Redis OSS 6.2 that is available. For example, when you create/modify a cache cluster, you set the --engine-version parameter to 6.2. The cluster will be launched with the current available preferred patch version of Redis OSS 6.2 at the creation/modification time. Specifying engine version 6.x in the API will result in the latest minor version of Redis OSS 6.

For existing 6.0 clusters, you can opt-in to the next auto minor version upgrade by setting the AutoMinorVersionUpgrade parameter to yes in the CreateCacheCluster, ModifyCacheCluster, CreateReplicationGroup or ModifyReplicationGroup APIs. ElastiCache will upgrade the minor version of your existing 6.0 clusters to 6.2 using self-service updates. For more information, see Self-service updates in Amazon ElastiCache.

When calling the DescribeCacheEngineVersions API, the EngineVersion parameter value will be set to 6.2 and the actual engine version with the patch version will be returned in the CacheEngineVersionDescription field. 

For more information on the Redis OSS 6.2 release, see Redis OSS 6.2 Release Notes at Redis OSS on GitHub.

ElastiCache version 6.0 for Redis OSS (enhanced)

Amazon ElastiCache introduces the next version of ElastiCache for the Redis OSS engine, which includes Authenticating Users with Role Based Access Control, client-side caching and significant operational improvements.

Beginning with Redis OSS 6.0, ElastiCache will offer a single version for each Redis OSS minor release, rather than offering multiple patch versions. ElastiCache will automatically manage the patch version of your running cache clusters, ensuring improved performance and enhanced security.

You can also opt-in to the next auto minor version upgrade by setting the AutoMinorVersionUpgrade parameter to yes and ElastiCache will manage the minor version upgrade, through self-service updates. For more information, see Service updates in ElastiCache.

You specify the engine version by using 6.0. ElastiCache will automatically invoke the preferred patch version of Redis OSS 6.0 that is available. For example, when you create/modify a cache cluster, you set the --engine-version parameter to 6.0. The cluster will be launched with the current available preferred patch version of Redis OSS 6.0 at the creation/modification time. Any request with a specific patch version value will be rejected, an exception will be thrown and the process will fail.

When calling the DescribeCacheEngineVersions API, the EngineVersion parameter value will be set to 6.0 and the actual engine version with the patch version will be returned in the CacheEngineVersionDescription field. 

For more information on the Redis OSS 6.0 release, see Redis OSS 6.0 Release Notes at Redis OSS on GitHub.

ElastiCache version 5.0.6 for Redis OSS (enhanced)

Amazon ElastiCache introduces the next version of ElastiCache for the Redis OSS engine, which includes bug fixes and the following cumulative updates:

  • Engine stability guarantee in special conditions.

  • Improved Hyperloglog error handling.

  • Enhanced handshake commands for reliable replication.

  • Consistent message delivery tracking via XCLAIM command.

  • Improved LFU field management in objects.

  • Enhanced transaction management when using ZPOP.

  • Ability to rename commands: A parameter called rename-commands that allows you to rename potentially dangerous or expensive Redis OSS commands that might cause accidental data loss, such as FLUSHALL or FLUSHDB. This is similar to the rename-command configuration in open source Redis OSS. However, ElastiCache has improved the experience by providing a fully managed workflow. The command name changes are applied immediately, and automatically propagated across all nodes in the cluster that contain the command list. There is no intervention required on your part, such as rebooting nodes.

    The following examples demonstrate how to modify existing parameter groups. They include the rename-commands parameter, which is a space-separated list of commands you want to rename:

    aws elasticache modify-cache-parameter-group --cache-parameter-group-name custom_param_group
--parameter-name-values "ParameterName=rename-commands,  ParameterValue='flushall restrictedflushall'" --region region

    In this example, the rename-commands parameter is used to rename the flushall command to restrictedflushall.

    To rename multiple commands, use the following:

    aws elasticache modify-cache-parameter-group --cache-parameter-group-name custom_param_group
--parameter-name-values "ParameterName=rename-commands,  ParameterValue='flushall restrictedflushall flushdb restrictedflushdb''" --region region

    To revert any change, re-run the command and exclude any renamed values from the ParameterValue list that you want to retain, as shown following:

    aws elasticache modify-cache-parameter-group --cache-parameter-group-name custom_param_group
--parameter-name-values "ParameterName=rename-commands,  ParameterValue='flushall restrictedflushall'" --region region

    In this case, the flushall command is renamed to restrictedflushall and any other renamed commands revert to their original command names.

    Note

    When renaming commands, you are restricted to the following limitations:

    • All renamed commands should be alphanumeric.

    • The maximum length of new command names is 20 alphanumeric characters.

    • When renaming commands, ensure that you update the parameter group associated with your cluster.

    • To prevent a command's use entirely, use the keyword blocked, as shown following:

      aws elasticache modify-cache-parameter-group --cache-parameter-group-name custom_param_group
--parameter-name-values "ParameterName=rename-commands,  ParameterValue='flushall blocked'" --region region

    For more information on the parameter changes and a list of what commands are eligible for renaming, see Redis OSS 5.0.3 parameter changes.

  • Redis OSS Streams: This models a log data structure that allows producers to append new items in real time. It also allows consumers to consume messages either in a blocking or nonblocking fashion. Streams also allow consumer groups, which represent a group of clients to cooperatively consume different portions of the same stream of messages, similar to Apache Kafka. For more information, see Streams.

  • Support for a family of stream commands, such as XADD, XRANGE and XREAD. For more information, see Streams Commands.

  • A number of new and renamed parameters. For more information, see Redis OSS 5.0.0 parameter changes.

  • A new Redis OSS metric, StreamBasedCmds.

  • Slightly faster snapshot time for Redis OSS nodes.

Important

ElastiCache has back-ported two critical bug fixes from Redis OSS open source version 5.0.1. They are listed following:

  • RESTORE mismatch reply when certain keys have already expired.

  • The XCLAIM command can potentially return a wrong entry or desynchronize the protocol.

Both of these bug fixes are included in ElastiCache for Redis OSS support for Redis OSS engine version 5.0.0 and are consumed in future version updates.

For more information, see Redis OSS 5.0.6 Release Notes at Redis OSS on GitHub.

ElastiCache version 5.0.5 for Redis OSS (deprecated, use version 5.0.6)

Amazon ElastiCache introduces the next version of ElastiCache for the Redis OSS engine;. It includes online configuration changes for ElastiCache of auto-failover clusters during all planned operations. You can now scale your cluster, upgrade the Redis OSS engine version and apply patches and maintenance updates while the cluster stays online and continues serving incoming requests. It also includes bug fixes.

For more information, see Redis OSS 5.0.5 Release Notes at Redis OSS on GitHub.

ElastiCache version 5.0.4 for Redis OSS (deprecated, use version 5.0.6)

Amazon ElastiCache introduces the next version of the Redis OSS engine supported by ElastiCache. It includes the following enhancements:

  • Engine stability guarantee in special conditions.

  • Improved Hyperloglog error handling.

  • Enhanced handshake commands for reliable replication.

  • Consistent message delivery tracking via XCLAIM command.

  • Improved LFU field management in objects.

  • Enhanced transaction management when using ZPOP.

For more information, see Redis OSS 5.0.4 Release Notes at Redis OSS on GitHub.

ElastiCache version 5.0.3 for Redis OSS (deprecated, use version 5.0.6)

Amazon ElastiCache introduces the next version of ElastiCache for the Redis OSS engine, which includes bug fixes.

ElastiCache version 5.0.0 for Redis OSS (deprecated, use version 5.0.6)

Amazon ElastiCache introduces the next major version of ElastiCache for the Redis OSS engine. ElastiCache version 5.0.0 for Redis OSS brings support for the following improvements:

  • Redis OSS Streams: This models a log data structure that allows producers to append new items in real time. It also allows consumers to consume messages either in a blocking or nonblocking fashion. Streams also allow consumer groups, which represent a group of clients to cooperatively consume different portions of the same stream of messages, similar to Apache Kafka. For more information, see Streams.

  • Support for a family of stream commands, such as XADD, XRANGE and XREAD. For more information, see Streams Commands.

  • A number of new and renamed parameters. For more information, see Redis OSS 5.0.0 parameter changes.

  • A new Redis OSS metric, StreamBasedCmds.

  • Slightly faster snapshot time for Redis OSS nodes.

ElastiCache version 4.0.10 for Redis OSS (enhanced)

Amazon ElastiCache introduces the next major version of ElastiCache for the Redis OSS engine. ElastiCache version 4.0.10 for Redis OSS brings support for the following improvements:

Redis OSS (cluster mode disabled) users running ElastiCache version 3.2.10 for Redis OSS can use the console to upgrade their clusters via online upgrade.

Comparing ElastiCache cluster resizing and encryption support
Version
Feature 3.2.6 3.2.10 4.0.10 and later
Online cluster resizing * No Yes Yes
In-transit encryption ** Yes No Yes
At rest encryption ** Yes No Yes
* Adding, removing, and rebalancing shards.
** Required for FedRAMP, HIPAA, and PCI DSS compliant applications. For more information, see Compliance validation for Amazon ElastiCache.

Past End of Life (EOL) versions (3.x)

ElastiCache version 3.2.10 for Redis OSS (enhanced)

Amazon ElastiCache introduces the next major version of ElastiCache for the Redis OSS engine. ElastiCache version 3.2.10 for Redis OSS (enchanced) introduces online cluster resizing to add or remove shards from the cluster while it continues to serve incoming I/O requests. ElastiCache for Redis OSS 3.2.10 users have all the functionality of earlier Redis OSS versions except the ability to encrypt their data. This ability is currently available only in version 3.2.6.

Comparing ElastiCache versions 3.2.6 and 3.2.10 for Redis OSS
Version
Feature 3.2.6 3.2.10
Online cluster resizing * No Yes
In-transit encryption ** Yes No
At rest encryption ** Yes No
* Adding, removing, and rebalancing shards.
** Required for FedRAMP, HIPAA, and PCI DSS compliant applications. For more information, see Compliance validation for Amazon ElastiCache.

For more information, see the following:

ElastiCache version 3.2.6 for Redis OSS (enhanced)

Amazon ElastiCache introduces the next major version of ElastiCache for the Redis OSS engine. ElastiCache version 3.2.6 for Redis OSS users have access to all the functionality of earlier Redis OSS versions, plus the option to encrypt their data. For more information, see the following:

ElastiCache version 3.2.4 for Redis OSS (enhanced)

Amazon ElastiCache version 3.2.4 introduces the next major version of ElastiCache for the Redis OSS engine. ElastiCache 3.2.4 users have all the functionality of earlier Redis OSS versions available to them, plus the option to run in cluster mode or non-cluster mode. The following table summarizes .

Comparing Redis OSS 3.2.4 non-cluster mode and cluster mode
Feature Non-cluster mode Cluster mode
Data partitioning No Yes
Geospatial indexing Yes Yes
Change node type Yes Yes *
Replica scaling Yes Yes *
Scale out No Yes *
Database support Multiple Single

Parameter group

default.redis3.2 **

default.redis3.2.cluster.on **

*  See Restoring from a backup into a new cache

** Or one derived from it.
Notes:

  • Partitioning – the ability to split your data across 2 to 500 node groups (shards) with replication support for each node group.

  • Geospatial indexing – Redis OSS 3.2.4 introduces support for geospatial indexing via six GEO commands. For more information, see the Redis OSS GEO* command documentation Commands: GEO on the Valkey Commands page (filtered for GEO).

For information about additional Redis OSS 3 features, see Redis OSS 3.2 release notes and Redis OSS 3.0 release notes.

Currently ElastiCache managed Valkey or Redis OSS (cluster mode enabled) does not support the following Redis OSS 3.2 features:

  • Replica migration

  • Cluster rebalancing

  • Lua debugger

ElastiCache disables the following Redis OSS 3.2 management commands:

  • cluster meet

  • cluster replicate

  • cluster flushslots

  • cluster addslots

  • cluster delslots

  • cluster setslot

  • cluster saveconfig

  • cluster forget

  • cluster failover

  • cluster bumpepoch

  • cluster set-config-epoch

  • cluster reset

For information about Redis OSS 3.2.4 parameters, see Redis OSS 3.2.4 parameter changes.

Past End of Life (EOL) versions (2.x)

ElastiCache version 2.8.24 for Redis OSS (enhanced)

Redis OSS improvements added since version 2.8.23 include bug fixes and logging of bad memory access addresses. For more information, see Redis OSS 2.8 release notes.

ElastiCache version 2.8.23 for Redis OSS (enhanced)

Redis OSS improvements added since version 2.8.22 include bug fixes. For more information, see Redis OSS 2.8 release notes. This release also includes support for the new parameter close-on-slave-write which, if enabled, disconnects clients who attempt to write to a read-only replica.

For more information on Redis OSS 2.8.23 parameters, see Redis OSS 2.8.23 (enhanced) added parameters in the ElastiCache User Guide.

ElastiCache version 2.8.22 for Redis OSS (enhanced)

Redis OSS improvements added since version 2.8.21 include the following:

  • Support for forkless backups and synchronizations, which allows you to allocate less memory for backup overhead and more for your application. For more information, see How synchronization and backup are implemented. The forkless process can impact both latency and throughput. When there is high write throughput, when a replica re-syncs, it can be unreachable for the entire time it is syncing.

  • If there is a failover, replication groups now recover faster because replicas perform partial syncs with the primary rather than full syncs whenever possible. Additionally, both the primary and replicas no longer use the disk during syncs, providing further speed gains.

  • Support for two new CloudWatch metrics.

    • ReplicationBytes – The number of bytes a replication group's primary cluster is sending to the read replicas.

    • SaveInProgress – A binary value that indicates whether or not there is a background save process running.

    For more information, see Monitoring use with CloudWatch Metrics.

  • A number of critical bug fixes in replication PSYNC behavior. For more information, see Redis OSS 2.8 release notes.

  • To maintain enhanced replication performance in Multi-AZ replication groups and for increased cluster stability, non-ElastiCache replicas are no longer supported.

  • To improve data consistency between the primary cluster and replicas in a replication group, the replicas no longer evict keys independent of the primary cluster.

  • Redis OSS configuration variables appendonly and appendfsync are not supported on Redis OSS version 2.8.22 and later.

  • In low-memory situations, clients with a large output buffer might be disconnected from a replica cluster. If disconnected, the client needs to reconnect. Such situations are most likely to occur for PUBSUB clients.

ElastiCache version 2.8.21 for Redis OSS

Redis OSS improvements added since version 2.8.19 include a number of bug fixes. For more information, see Redis OSS 2.8 release notes.

ElastiCache version 2.8.19 for Redis OSS

Redis OSS improvements added since version 2.8.6 include the following:

  • Support for HyperLogLog. For more information, see Redis OSS new data structure: HyperLogLog.

  • The sorted set data type now has 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.

  • Support for the HyperLogLogBasedCommands CloudWatch metric. For more information, see Metrics for Valkey and Redis OSS.

ElastiCache version 2.8.6 for Redis OSS

Redis OSS improvements added since version 2.6.13 include the following:

  • Improved resiliency and fault tolerance for read replicas.

  • Support for partial resynchronization.

  • Support for user-defined minimum number of read replicas that must be available at all times.

  • Full support for pub/sub—notifying clients of events on the server.

  • Automatic detection of a primary node failure and failover of your primary node to a secondary node.

ElastiCache version 2.6.13 for Redis OSS

ElastiCache version 2.6.13 for Redis OSS was the initial version of ElastiCache that supported Redis OSS. Multi-AZ is not supported on ElastiCache version 2.6.13 for Redis OSS.

ElastiCache versions for Redis OSS end of life schedule

This section defines end of life (EOL) dates for older major versions as they are announced. This allows you to make version and upgrade decisions for the future.

Note

ElastiCache versions from 5.0.0 to 5.0.5 for Redis OSS are deprecated. Use versions 5.0.6 or greater.

The following table summarizes each version and its announced EOL date, as well as the recommended upgrade target version.

Past EOL

Source Major Version Source Minor Versions Recommended Upgrade Target EOL Date
Version 3

3.2.4, 3.2.6 and 3.2.10

Version 6.2 or higher

Note

For US-ISO-EAST-1, US-ISO-WEST-1, and US-ISOB-EAST-1 Regions, we recommend 5.0.6 or higher.

July 31, 2023
Version 2

2.8.24, 2.8.23, 2.8.22, 2.8.21, 2.8.19, 2.8.12, 2.8.6, 2.6.13

Version 6.2 or higher

Note

For US-ISO-EAST-1, US-ISO-WEST-1, and US-ISOB-EAST-1 Regions, we recommend 5.0.6 or higher.

January 13, 2023

Supported ElastiCache for Memcached versions

ElastiCache supports the following Memcached versions and upgrading to newer versions. When upgrading to a newer version, pay careful attention to the conditions that if not met cause your upgrade to fail.

ElastiCache version 1.6.22 for Memcached

ElastiCache for Memcached version 1.6.22 for Memcached adds support for Memcached version 1.6.22. It includes no new features, but does include bug fixes and cumulative updates from Memcached 1.6.18.

For more information, see ReleaseNotes1622 at Memcached on GitHub.

ElastiCache version 1.6.17 for Memcached

ElastiCache for Memcached version 1.6.17 for Memcached adds support for Memcached engine version 1.6.17. It includes no new features, but does include bug fixes and cumulative updates from Memcached 1.6.17.

For more information, see ReleaseNotes1617 at Memcached on GitHub.

ElastiCache version 1.6.12 for Memcached

ElastiCache for Memcached version 1.6.12 for Memcached adds support for Memcached engine 1.6.12 and encryption in-transit. It also includes bug fixes and cumulative updates from Memcached 1.6.6.

For more information, see ReleaseNotes1612 at Memcached on GitHub.

ElastiCache version 1.6.6 for Memcached

ElastiCache for Memcached version 1.6.6 for Memcached adds support for Memcached version 1.6.6. It includes no new features, but does include bug fixes and cumulative updates from Memcached 1.5.16. ElastiCache for Memcached does not include support for Extstore.

For more information, see ReleaseNotes166 at Memcached on GitHub.

ElastiCache version 1.5.16 for Memcached

ElastiCache version 1.5.16 for Memcached adds support for Memcached version 1.5.16. It includes no new features, but does include bug fixes and cumulative updates from Memcached 1.5.14 and Memcached 1.5.15.

For more information, see Memcached 1.5.16 Release Notes at Memcached on GitHub.

ElastiCache version 1.5.10 for Memcached

ElastiCache version 1.5.10 for Memcached supports the following Memcached features:

  • Automated slab rebalancing.

  • Faster hash table lookups with murmur3 algorithm.

  • Segmented LRU algorithm.

  • LRU crawler to background-reclaim memory.

  • --enable-seccomp: A compile-time option.

It also introduces the no_modern and inline_ascii_resp parameters. For more information, see Memcached 1.5.10 parameter changes.

Memcached improvements added since ElastiCache version 1.4.34 for Memcached include the following:

  • Cumulative fixes, such as ASCII multigets, CVE-2017-9951 and limit crawls for metadumper.

  • Better connection management by closing connections at the connection limit.

  • Improved item-size management for item size above 1MB.

  • Better performance and memory-overhead improvements by reducing memory requirements per-item by a few bytes.

For more information, see Memcached 1.5.10 Release Notes at Memcached on GitHub.

ElastiCache version 1.4.34 for Memcached

ElastiCache version 1.4.34 for Memcached adds no new features to version 1.4.33. Version 1.4.34 is a bug fix release that is larger than the usual such release.

For more information, see Memcached 1.4.34 Release Notes at Memcached on GitHub.

ElastiCache version 1.4.33 for Memcached

Improvements added since version 1.4.24 include the following:

  • Ability to dump all of the metadata for a particular slab class, a list of slab classes, or all slab classes. For more information, see Memcached 1.4.31 Release Notes.

  • Improved support for large items over the 1 megabyte default. For more information, see Memcached 1.4.29 Release Notes.

  • Ability to specify how long a client can be idle before being asked to close.

    Ability to dynamically increase the amount of memory available to Memcached without having to restart the cluster. For more information, see Memcached 1.4.27 Release Notes.

  • Logging of fetchers, mutations, and evictions are now supported. For more information, see Memcached 1.4.26 Release Notes.

  • Freed memory can be reclaimed back into a global pool and reassigned to new slab classes. For more information, see Memcached 1.4.25 Release Notes.

  • Several bug fixes.

  • Some new commands and parameters. For a list, see Memcached 1.4.33 added parameters.

ElastiCache version 1.4.24 for Memcached

Improvements added since version 1.4.14 include the following:

  • Least recently used (LRU) management using a background process.

  • Added the option of using jenkins or murmur3 as your hash algorithm.

  • Some new commands and parameters. For a list, see Memcached 1.4.24 added parameters.

  • Several bug fixes.

ElastiCache version 1.4.14 for Memcached

Improvements added since version 1.4.5 include the following:

  • Enhanced slab rebalancing capability.

  • Performance and scalability improvement.

  • Introduced the touch command to update the expiration time of an existing item without fetching it.

  • Auto discovery—the 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.

ElastiCache version 1.4.5 for Memcached

ElastiCache version 1.4.5 for Memcached was the initial engine and version supported by Amazon ElastiCache for Memcached).