Cache Stampede

Definitions

1. A failure mode where a popular cache entry expires, causing many concurrent requests to simultaneously hit the database to regenerate it. The sudden load spike can cascade into a database overload. Mitigated by cache locking (only one request regenerates), probabilistic early expiration, or stale-while-revalidate patterns.

   In plain English: When a popular cached item expires and hundreds of requests slam the database at once trying to rebuild it.

   Example: "The homepage cache expired and 500 concurrent requests all hit the database simultaneously — classic cache stampede. Add a mutex so only one request regenerates."

Related Terms

• LRU Cache
• Stale-While-Revalidate
• ETag
• Disk Cache
• Inline Cache
• Memcached
• Prefetch
• Query Cache
• Write Through