Evictionbased

Evictionbased is an adjective used to describe systems, policies, or algorithms that manage limited resources primarily by evicting items to free space. The term is commonly encountered in computing contexts such as caches, memory managers, databases, and storage systems, where capacity constraints require deciding which data to remove when new data must be stored. Evictionbased design emphasizes the eviction decision as the central mechanism for resource management, rather than keeping all data available locally.

In cache and memory management, evictionbased approaches rely on an eviction policy to select candidates for removal when capacity is reached. The goals typically include minimizing cache misses, maximizing hit rate, and reducing latency. Common eviction-based policies include Least Recently Used (LRU), Least Frequently Used (LFU), FIFO, Random, and more sophisticated schemes like Clock or ARC. Each policy embodies a heuristic about which data will be useful again soon and thus should be retained or removed accordingly.

Evictionbased decisions also occur in operating systems through page replacement algorithms that decide which memory pages to evict to make room for others. In databases and storage systems, eviction-based buffer managers and cache layers use similar principles to decide which pages or blocks to evict from memory buffers.

Benefits of evictionbased designs include simplicity and predictable behavior, especially in stable workloads. Drawbacks can include vulnerability to thrashing under rapidly changing access patterns and suboptimal performance if the eviction policy does not align with actual usage. Evictionbased approaches are often contrasted with retention- or prefetching-oriented strategies that attempt to keep data in memory proactively.