cacheeviction

Cache eviction refers to the process by which data is removed from a computer's cache memory to make space for new information. Caches, such as CPU caches or database caches, temporarily store frequently accessed data to improve performance by reducing the time required to retrieve it. When the cache reaches its capacity, eviction policies determine which data should be removed to accommodate new entries.

Common eviction strategies include Least Recently Used (LRU), Least Frequently Used (LFU), and First-In-First-Out (FIFO). LRU removes the least recently accessed item, assuming that recently used data is more likely to be needed again soon. LFU prioritizes removing the least frequently accessed items, while FIFO follows a strict chronological order, expelling the oldest entries first. Other methods, such as Random Eviction, remove items at random, though this is less common due to its unpredictability.

Cache eviction is critical in systems where memory constraints exist, such as web browsers, database management systems, and operating systems. For example, web browsers use cache eviction to manage stored web pages, images, and scripts, ensuring that frequently visited sites load faster. Similarly, databases employ caching mechanisms to speed up query responses, and eviction policies help maintain optimal performance by balancing memory usage and data availability.

The choice of eviction policy depends on the specific use case, workload patterns, and performance requirements. Poorly designed eviction strategies can lead to increased latency or repeated data retrieval, degrading system efficiency. Conversely, well-tuned eviction mechanisms enhance responsiveness and resource utilization, making them a key consideration in system design and optimization.