cachestatus

The term cachestatus refers to the current state or outcome of a cache lookup in computing. It indicates whether the requested data was retrieved from a cache or had to be loaded from the primary data store. The concept applies across different layers of a system, including processor caches, application caches, and web caches. It is not a single standardized interface, but a descriptive label used in logs, metrics, and API responses.

In CPU caches, status is typically described in terms of hits, misses, and sometimes evictions. In web and HTTP caches, common statuses include HIT, MISS, EXPIRED, STALE, and REVALIDATED, reflecting whether a response came from the cache and whether it remains fresh. In distributed caches and CDNs, the status can also reflect back-end fetches, evictions, or revalidation decisions.

Cache status is often conveyed via an enumeration or code in APIs, along with additional metadata such as latency, TTL, and size. Publishers and developers monitor cache-status to measure performance, tune eviction policies, and improve data consistency. Key metrics include cache-hit rate, miss rate, latency, and the lifespan of cached entries.

Best practices include clear definitions of status values, consistent instrumentation across components, and careful handling of stale or invalid data to avoid serving inaccurate results. Understanding cachestatus helps diagnose bottlenecks and optimize caching strategies.