What happens on a cache hit and miss?

Goal & mental model verified

Spring’s cache abstraction delegates storage to a backing implementation. @Cacheable can reuse results; eviction and updates define freshness behavior. An annotation alone does not define TTL or make a distributed cache consistent.

Worked example · design exercise synthesis

For a policy summary, use a key containing tenant and policy ID. Evict or update affected summaries after successful policy changes under an explicitly chosen consistency policy.

Engineering decision synthesis

Cache expensive, repeatedly read data with an acceptable staleness budget. Choose local versus shared storage by consistency, footprint and latency requirements.

Pitfall & diagnosis synthesis

Missing tenant identity in a key can reuse another tenant’s data. Default proxy-based caching also has self-invocation limits. Cache invalidation and database commit ordering need care.

Improve & validate synthesis

Measure hit ratio, stale reads and miss cost. Exercise concurrent misses and updates; bound entry size and TTL using the provider’s configuration.