Posted On: Jun 14, 2018

Amazon ElastiCache for Redis, today announced support for Redis 4.0.10. Now you can take advantage of the new caching improvements and better memory management capabilities in Redis 4.0 and improve performance and memory usage of your in-memory data processing workloads.

Below are the key highlights of the announcement.

 - New eviction policy for caching improvements – Redis 4.0 now supports a frequency-based LFU (Least Frequently Used) eviction policy for evicting keys in addition to the existing time-based LRU (Least Recently Used) policy. The new LFU policy provides a better cache hit ratio by keeping frequently used data in-memory irrespective of the last time it was accessed.

 - A new family of commands to understand memory utilization – Redis 4.0 introduces a new family of commands including MEMORY which provides better insights on Redis memory usage. The MEMORY DOCTOR command provides remedy information for memory related issues, and the MEMORY USAGE command provides precise memory utilization for a key and its value. Other new commands include MEMORY MALLOC-STATS, MEMORY PURGE, and MEMORY STATS.

 - Active memory defragmentation – Redis 4.0 can defragment the memory online allowing for more efficient memory utilization and more available memory for your data.

 - Asynchronous deletes and flushes – Redis 4.0 allows commands like DEL, FLUSHDB, and FLUSHALL to free up memory asynchronously (run in a different thread vs. the main process). This enables more flexibility, better performance, and faster response times for your applications.

In addition to supporting Redis 4.0.10, ElastiCache for Redis adds support for online cluster resizing in the new release.

The new functionality is available in all AWS regions. To get started with just a few clicks, log into the AWS Management Console.