We are pleased to announce that Amazon ElastiCache now supports Memcached version 1.4.24. Customers can launch modern clusters with Memcached 1.4.24,as well as upgrade existing ones to the modern engine version. Compared to version 1.4.14 (until now the latest version supported by ElastiCache Memcached) this version adds support for LRU management as a background task, a modern hashing algorithm, or modern commands and miscellaneous bug fixes.
For the full list of improvements in Memcached 1.4.24 click here. You can easily launch an ElastiCache Memcached cluster with engine version 1.4.24 via a few clicks on the AWS Management Console.
Source: amazon.com