SystemCache

SystemCache is a term used to describe the set of caching mechanisms that store frequently accessed data in fast storage to reduce access times in a computing system. It spans both hardware and software layers, including CPU caches (L1/L2/L3) and software-managed caches in RAM such as operating system page caches, file system caches, and application or database buffer caches. The primary objective is to minimize latency and I/O bandwidth by serving data from a faster medium when possible.

Data placed in SystemCache is managed by replacement policies, e.g., least recently used (LRU), clock, or more advanced algorithms such as ARC or LFU. Write strategies vary; write-through updates both cache and underlying storage, while write-back defers writes until eviction. Caching forms a hierarchy, with fast but small caches closer to the processor and larger caches in memory or on storage devices.

Maintaining correctness requires coherence and consistency with the underlying data store; caches are invalidated or updated when the source data changes, and synchronization is critical in multi-threaded or multi-process environments.

Impact and tuning: caching improves read throughput and lowers latency, but can increase memory usage and risk cache pollution or serving stale data if not carefully configured. System administrators tune cache parameters (for example, Linux page cache behavior or database buffer pool sizing) to balance performance and resource constraints.

See also: CPU cache, page cache, buffer cache, database buffer pool.