Overview
In-memory caching (e.g., Redis, Memcached) is used to improve application performance by reducing the load on backend databases and lowering latency for frequently accessed data. Because RAM is much faster than disk, cached data can be retrieved in microseconds.
Key Concepts
- Cache Hit/Miss: A 'hit' occurs when the requested data is in the cache; a 'miss' occurs when it is not.
- TTL (Time to Live): The duration for which an item remains in the cache before it expires.
- Eviction Policies: Rules for removing items when the cache is full (e.g., Least Recently Used - LRU).
Use Cases
- Session management.
- Leaderboards in gaming.
- Caching database query results.
- Real-time analytics.