Memcached
DatabasesMemcached is an in-memory, distributed key-value caching system used to speed up dynamic websites and applications by storing frequently requested data in RAM. It reduces database queries and backend processing by serving cached objects like query results, sessions, or rendered fragments. Memcached is simple, fast, and network-accessible, but it is volatile and typically used as a cache layer, not a primary database.
How It Works
Memcached runs as a daemon that keeps data in RAM and exposes a lightweight protocol over TCP or UDP. Applications store and retrieve values by key (for example, "product:123" or "homepage:html"). When a request arrives, the app checks Memcached first; on a cache hit it returns the value immediately, and on a miss it fetches from the database or computes the result, then writes it back to Memcached with an expiration time (TTL).
It is designed for simplicity: values are opaque blobs, there are no complex queries, and persistence is not built in. Eviction is automatic when memory fills up, typically using an LRU-like policy, and all cached data is lost on restart. Memcached can scale horizontally by distributing keys across multiple nodes (often via consistent hashing in the client library), which increases total cache capacity and throughput.
Why It Matters for Web Hosting
For hosting buyers, Memcached support can be a practical performance feature: it can lower database load, reduce page generation time, and help a site handle traffic spikes with the same CPU and database resources. When comparing plans, look for whether Memcached is available, how it is managed (self-managed vs managed service), network access rules, memory limits, and whether your stack (PHP, WordPress, Laravel, Magento) has a compatible integration.
Common Use Cases
- Caching database query results to reduce repeated reads
- Storing computed objects (product catalogs, user profiles, API responses) for faster retrieval
- Full-page or fragment caching for dynamic pages and templates
- Session storage for stateless application servers (when supported by the app framework)
- Rate limiting counters and short-lived tokens using atomic increment operations
Memcached vs Redis
Memcached focuses on simple, high-speed key-value caching with minimal features, which can make it easy to operate and very fast for straightforward cache workloads. Redis is also used as a cache but adds richer data structures, scripting, optional persistence, replication, and more advanced eviction and durability options. In hosting terms, choose Memcached for basic cache acceleration and Redis when you need features like persistence, pub/sub, queues, or complex caching patterns.