Overview of Memcached
Memcached is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating Database load. Originally developed by Brad Fitzpatrick for LiveJournal in 2003, it has since become a staple in the infrastructure of some of the world's largest websites, including Facebook and Twitter.
Technical Architecture
As an In-Memory Database, Memcached operates as a Key-Value Store for small chunks of arbitrary data such as strings or objects. It employs a Client-Server Model where the server maintains a reactive Hash Table. When the table fills up, Memcached uses a Least Recently Used (LRU) algorithm to discard the oldest data to make room for new entries. Because it stores data purely in RAM, it offers extremely low Latency compared to disk-based storage solutions.
The system is designed to be simple yet powerful. It does not support complex data types or internal programming logic, which distinguishes it from Redis. Its Distributed Computing nature allows it to scale horizontally by adding more nodes to a Cluster. Developers can find the source code and documentation on the Official Memcached Website or review community-driven insights on Wikipedia.
Implementation and Performance
Typical use cases for Memcached include Session Management, results of API calls, and Page Caching. By reducing the number of times an application must read from a slow Relational Database, it significantly improves Throughput and user experience. It is often paired with languages like PHP, Python, and Node.js using standardized client libraries.