Amazon ElastiCache is a fully managed in-memory data store and cache service by Amazon Web Services (AWS). The service improves the performance of web applications by retrieving information from managed in-memory caches, instead of relying entirely on slower disk-based databases. ElastiCache supports two open-source in-memory caching engines: Memcached and Redis (also called "ElastiCache for Redis"). Amazon ElastiCache was first released on August 22, 2011, supporting memcached. This was followed by support for reserved instances on April 5, 2012 and Redis on September 4, 2013.