Cache invalidation.

also: invalidate the cache · invalidating the cache · cache invalidations · write-invalidate · write-update · invalidation strategy · invalidation strategies

Removing or updating cached entries when the source data changes, so readers don't keep seeing stale values.

the two-minute refresher

One of the two hard things in computer science, for good reason.
Strategies: TTL, event-driven invalidation, versioned keys, write-invalidate vs write-update.
Decide per data type how stale is acceptable: prices and stock differ from avatars.
Combine them: events for freshness, TTL as the safety net when an event is lost.

Where the course teaches it

W04 · Day 2Invalidation Strategieslearn it →W04 · Day 2Invalidation Strategiesrevisit →W04 · Day 5Multi-Tier Cachingrevisit →

Related concepts

← all concepts

Cache invalidation.

also: invalidate the cache · invalidating the cache · cache invalidations · write-invalidate · write-update · invalidation strategy · invalidation strategies

Removing or updating cached entries when the source data changes, so readers don't keep seeing stale values.

the two-minute refresher

One of the two hard things in computer science, for good reason.
Strategies: TTL, event-driven invalidation, versioned keys, write-invalidate vs write-update.
Decide per data type how stale is acceptable: prices and stock differ from avatars.
Combine them: events for freshness, TTL as the safety net when an event is lost.

Where the course teaches it

W04 · Day 2Invalidation Strategieslearn it →W04 · Day 2Invalidation Strategiesrevisit →W04 · Day 5Multi-Tier Cachingrevisit →