Redis Patterns

Advanced Redis usage beyond simple key-value caching.

Data Structure Selection

Use Case                → Structure      → Why
Session store           → Hash           → Partial field updates without full deserialize
Rate limiter            → Sorted Set     → ZRANGEBYSCORE for sliding window
Job queue               → List + Stream  → BRPOPLPUSH for reliable queue
Leaderboard             → Sorted Set     → ZREVRANGE with scores
Unique visitors         → HyperLogLog    → O(1) cardinality, 0.81% error
Feature flags           → Hash           → HGET per flag, HGETALL for bulk
Presence (who's online) → Set            → SADD/SREM, SMEMBERS
Geolocation             → Geo            → GEOSEARCH within radius

Distributed Lock (Redlock-lite)