Redis is an open-source, in-memory data structure store, used as a database, cache and message broker.
It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries.
Redis has built-in replication, Lua Scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Resia Sentinel and automatic partitioning with Redis Cluster.
We can run atomic operations on these types, like appending to a string; incrementing the value in a hash; pushing an element to a list; computing set intersection, union and difference; or getting the member with highest ranking in a sorted set.
In order to achieve its outstanding performance, Redis works with an in-memory dataset. Depending on your use case, you can persist it either by dumping the dataset to disk every once in a while, or by appending each command to a log.
Redis also supports trivial-to-setup master-slave asychronous replication, with very fast non-blocking first synchronization, auto-reconnection with partial resynchronization on net split.
Other features
- Transactions
- Pub/Sub
- Lua Scripting
- Keys with a limited time-to-live
- LRU eviction of keys
- Automatic failover