21CTO

May 10, 2016 · Backend Development

How to Prevent Cache Penetration, Concurrency, and Expiration Issues in Redis and Memcached

This article explains the three common cache problems—penetration, concurrency, and expiration—illustrates why they occur in high‑traffic systems, and provides practical techniques such as pre‑setting placeholder values, locking, and randomizing TTLs to keep databases healthy.