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.

Memcached version 1.6.17

ElastiCache for Memcached adds support for Memcached version 1.6.17. It includes no new features, but does include bug fixes and cumulative updates from Memcached 1.6.12.

For more information, see ReleaseNotes1617 at Memcached on GitHub.

Memcached version 1.6.12

ElastiCache for Memcached adds support for Memcached version 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.

Memcached version 1.6.6

ElastiCache 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.

Memcached version 1.5.16

ElastiCache 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.

Memcached version 1.5.10

ElastiCache for Memcached version 1.5.10 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 for Memcached version 1.4.34 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.

Memcached version 1.4.34

ElastiCache for Memcached version 1.4.34 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.

Memcached version 1.4.33

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.

Memcached version 1.4.24

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.

Memcached version 1.4.14

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.

Memcached version 1.4.5

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