This week in caching: a decision checklist for Memcached vs Redis

This week in caching: a decision checklist for Memcached vs Redis

Stop cargo-culting the choice. Walk these five questions.

— Do you need data structures? — sorted sets, lists, counters → Redis. Pure key→blob string cache → Memcached is leaner and simpler.
— Need persistence or replication? — Redis has RDB/AOF and replicas; Memcached is volatile-only by design. Sessions lean Redis.
— Want true multithreaded throughput? — Memcached is multithreaded out of the box; single Redis is one core (cluster or multiple instances to scale CPU).
— Memory efficiency for tiny values? — Memcached's slab allocator can edge out Redis for huge counts of small, uniform items.
— One system to operate? — Redis often wins by covering cache + sessions + queues, fewer moving parts.

Credit to the classic Redis vs Memcached comparisons from the AWS ElastiCache docs.

Bookmark: antirez's old 'Redis vs Memcached' post — still the clearest framing.