Understanding Redis: Features, Use Cases, and Architectural Evolution

Redis is a BSD‑licensed open‑source project that stores structured data in memory, usable as a database, cache, and message broker. It supports strings, lists, hashes, sets, sorted sets, bitmaps, hyperloglogs, and geospatial indexes.

The article first describes a simple API caching scenario, showing how in‑process memory caching can alleviate latency but leads to memory pressure, prompting the move to a dedicated Redis server.

Key Redis features are then explained: persistence (RDB/AOF) to mitigate data loss, Sentinel and replication for high availability, and clustering for horizontal scaling using hash slots.

Client‑side considerations include the rich data types, atomic transactions, Lua scripting for complex atomic operations, pipelines to reduce TCP overhead, and the Redlock algorithm for distributed locking, with example commands provided.

SET resource_name my_random_value NX PX 30000
if redis.call("get",KEYS[1]) == ARGV[1] then
    return redis.call("del",KEYS[1])
else
    return 0
end

Finally, the article emphasizes understanding Redis at an abstract level to choose appropriate solutions for specific scenarios, rather than focusing solely on implementation details.