Elasticache - seanremenyi/Notes_aws_developer GitHub Wiki

Memory is faster than disk in-memory cache (key-Value) makes it easy to deploy, operate and scale in-memory cache in the cloud Improves db performace it allows you to retrieve information from fast, in-memory caches instead of sower disk-based storage. Great for read-heavy Db workloads Caching the results of I/O intenensive db queries also for retaining session data for distributed applications can use elasticache cluster to cache freequently accessed data for faster application, application servers can retrwieve data from there

Memcached Great for object caching Scales horizontally but no persistence, multi az or failover. good choice for basic caching and you want you caching model to be as simple as possible. in memory key-value data store if object cahing is your primary goal keep it as simple as possible dont need persistence/multi az dont need to support advanced data types or sorting

Redis More sophisticated solution with enterprise features like persistence, replication, Multi-AZ and failover Supports sorting and ranking data (e.g. for gamin leaderboards) and complex data types like lists and hashes in memory key-value data store performing data sorting and ranking, ,such as leaderboards have advanced data types, such as lists and hashes need data persistence need multi az

if a db is under a lot of stress, know when to use elasticache, if db is particular read heavy and data is not changed very frequently (elasticache will struggle to have the latest data available) When elasitcache can't help wont help alleviate heavy write loads (will need to scale up db) Olap queries(think about using redsihft instead)