Redis Tutorial

The In-Memory Data Store Redis (Remote Dictionary Server) is an open-source in-memory data structure store. It answers commands at microsecond latency, which makes it the default ...

Install on Linux Redis runs as a service on port 6379. Install on Windows Redis is not natively supported on Windows; use WSL2 for a real Redis, or the Microsoft-maintained port ...

Strings Keys and Expiry Generic Utilities Instrumentation Key Points Strings plus INCR/EXPIRE cover counters and caches. TTL and KEYS shape retention and admin. SELECT switches ...

Lists Lists make fifo queues and recent-activity feeds. Sets Sets handle uniqueness, tags and membership checks. Sorted Sets Sorted sets power leaderboards, queues with priority ...

Why Persist at All Redis keeps data in memory, so a restart would lose everything unless persistence is configured. Two mechanisms exist: RDB snapshots and AOF (Append Only File). ...

Cache-Aside (Lazy Loading) Ask Redis for the key. On miss, load from the database. Write the value back with a TTL. Serve subsequent reads from Redis. TTL expires stale entries; ...

Dependencies Spring Data Redis supplies RedisTemplate, repositories and cache support. Configuration Use RedisTemplate StringRedisTemplate serializes strings easily; RedisTemplate ...

Pub/Sub Channels fan out messages to subscribers; use it for notifications, not for durable queues - missed messages are gone. Transactions (MULTI/EXEC) MULTI queues commands and ...

Replication A replica (slaveof/replicaof) copies the primary's dataset. Reads can scale to replicas, and the primary stays the write owner. Replicas also keep RDB files reused for ...

Operational Best Practices Set maxmemory and an eviction policy before load. Enable AOF with everysec fsync for durability. Bind Redis to private interfaces only. Move backup ...