redis

redis

Data Structures

• Strings: SET key value, GET key, INCR, SETEX with TTL.
• Lists: LPUSH, RPUSH, LPOP, LRANGE for queues.
• Hashes: HSET, HGETALL, HINCRBY for objects.
• Sets: SADD, SMEMBERS, SINTER, SUNION for relationships.
• Sorted Sets: ZADD, ZRANGE, ZRANK, ZREVRANGE for leaderboards.
• Streams: XADD, XREAD, XREADGROUP, XACK for event sourcing.

Caching Patterns

• Cache-aside: app checks cache first, falls back to DB, writes to cache.
• Write-through: app writes to cache first, cache syncs to DB.
• Write-behind: async batch write to DB for high throughput.
• Use SET NX for distributed locks; EXPIRE/TTL for auto-eviction.
• Eviction policies: LRU, LFU, TTL, random, noeviction.

Pub/Sub

• PUBLISH channel message — fire-and-forget messaging.
• SUBSCRIBE channel / PSUBSCRIBE pattern* for pattern subscriptions.
• Use Redis Streams instead for persistent message delivery.

Redis Stack

• FT.CREATE idx ON hash PREFIX 1 "doc:" SCHEMA title TEXT WEIGHT 5.0 — RediSearch.
• JSON.SET, JSON.GET — native JSON document store.
• TS.CREATE, TS.ADD — time-series data with retention policies.
• GRAPH.QUERY — property graph queries with Cypher syntax.

Lua Scripting

• EVAL "return redis.call('GET', KEYS[1])" 1 key — atomic server-side scripts.
• SCRIPT LOAD + EVALSHA for cached script execution.

RedisInsight

• GUI: key browser, profiler, slow log analyzer, cluster topology.