Redis.io

Redis Basics

Redis is a key-value store that lives in memory, and executes one command at a time. In-memory nature makes it very fast (a single node can handle 100K writes per second), while the sequential model makes it easy to reason about operations.

Redis has two persistence modes. RDB takes periodic snapshots, and AOF logs every write but only fsyncs once per second by default – therefore, Redis is not durable. While you can configure AOF to fsync on every write, you’d lose the speed that you came to Redis for.