Cacheplass

Cacheplass is a term used in computing to denote a designated storage area where copies of frequently accessed data are kept to speed up future requests. By serving data from the cache, systems can reduce latency and decrease load on slower storage layers. The concept applies to hardware, software, and network contexts.

In hardware, CPU caches are small, fast memory layers located close to the processor. They are organized into levels (L1, L2, L3) and often into lines and sets with a specified associativity. Data are kept in the cache based on locality of reference; a cache hit returns the data quickly, while a miss requires fetching from a lower level or main memory. Replacement policies, such as least-recently-used, determine what to evict when space is needed.

Software and networks use caches to store results of expensive operations or responses to client requests. Web caches in browsers, reverse proxies, and content delivery networks store HTTP responses and use headers like Cache-Control and ETag to manage freshness and invalidation. Databases maintain buffer caches of frequently accessed pages, and in-memory stores like Redis or Memcached provide application-level caching.

Cache effectiveness is described by metrics such as hit rate, miss rate, and average latency. Design involves choosing cache size, placement, and replacement strategy, as well as handling coherence and invalidation in multi-core or distributed environments. Properly managed caches can improve performance, but improper invalidation or stale data risks correctness and user experience.