Redis
Redis is an in-memory data store used as a cache, message broker, and session store, with data structures like sorted sets and streams. Sub-millisecond reads make it the default choice for hot-path data.
Pros
- Sub-millisecond latency. In-memory storage answers reads faster than any disk database. 0
- Rich data structures. Sorted sets, streams, and pub/sub solve queues and leaderboards natively. 0
- Simple protocol. Every language has a mature, easy client library. 0
- Proven at scale. Cluster mode shards data across nodes transparently. 0
Cons
- RAM-bound cost. Dataset size is capped by expensive memory, not cheap disk. 0
- Weak durability defaults. Crash recovery can lose recent writes unless AOF is tuned. 0
- Single-threaded core. One slow command blocks every other operation. 0
- License turbulence. The 2024 license change spawned the Valkey fork and ecosystem split. 0