An application cache stores disposable copies of source data. This track tests four failure boundaries: an old fill after a write, a popular key expiring across replicas, memory pressure shifting work to the source, and cached absence or stale values outliving their meaning.
Topics in this track
- Cache-Aside Fill Races and Version Guards — Prevent an old cache fill from replacing a newer database result after a concurrent write.
- Cache Stampede, Singleflight, and Hot-Key Budgets — Bound source load when a popular cache entry expires or vanishes across many application instances.
- Cache Memory, Eviction, and Degraded Read Paths — Treat cache capacity and eviction policy as load-control decisions with a tested source fallback.
- Negative Cache Entries and Stale-Read Contracts — Cache absence and old values only when their user-visible meaning and maximum age are explicit.
Prerequisite paths
Data Persistence; HTTP Delivery and Cache Ownership; Tenant Scope in Cache and Background Work.
Practice and check
Build Project: permit cache recovery and consistency and review Web Development: application cache contracts quiz.