Redis Resources

Knowledge

• Docs: "Data types", Redis
  Official overview of Redis's in-memory data structures and how they shape what Redis is actually good at storing and manipulating. Use for: the memory-model foundation everything else in this workspace assumes.
• Docs: "Key eviction", Redis
  Official reference for eviction policies (noeviction, the allkeys-* and volatile-* families) and exactly when Redis starts evicting keys under a memory limit. Use for: choosing and defending an eviction policy, and recognizing when a system is silently relying on the wrong one.
• Docs: "Persistence", Redis
  Official docs on RDB snapshotting and AOF logging: what each guarantees on a crash, what each costs, and how they can be combined. Use for: comparing what Redis actually guarantees against Postgres's WAL-backed durability.
• Docs: "Distributed locks with Redis", Redis
  Official docs describing the Redlock algorithm for a distributed lock built on Redis. Use for: what a "real" distributed lock attempt looks like, before reading the critique below.
• Article: "How to do distributed locking", Martin Kleppmann
  A widely-cited critique of Redlock's safety guarantees under process pauses and clock drift, from the author of Designing Data-Intensive Applications. Use for: the specific failure modes behind "a lock that is not one", and why a naive Redis-based lock is a correctness risk, not just a performance one.
• Docs: "Redis cache-aside", Redis
  Official docs on the cache-aside pattern: checking Redis first, falling back to the primary database on a miss, writing the result back with a TTL, and invalidating (not rewriting) the cache key on a write. Use for: what correct cache-aside usage looks like, the baseline the cache-treated-as-a-store anti-pattern deviates from.
• Docs: "Scaling with Redis Cluster", Redis
  Official docs on how Redis Cluster shards keys and what a client and an operator each have to account for as a result. Use for: reasoning about Cluster's compromises without needing to operate one.
• Docs: "High availability with Redis Sentinel", Redis
  Official docs on Sentinel's failure-detection and automatic-failover model for a Redis primary/replica setup. Use for: reasoning about Sentinel's compromises, the same way as Cluster above.

Gaps

• No source yet with a concrete, worked example of "a cache treated as a store" failing in production (a real incident write-up), as opposed to the abstract pattern description in this mission; worth closing once lesson design reaches that specific anti-pattern.