Memcached

Memcached was created by Brad Fitzpatrick in 2003 to solve performance problems at his photo-sharing website LiveJournal, which was struggling with database load. He open-sourced the software, and it has since been adopted by major platforms including Facebook, Reddit, and Twitter to cache frequently accessed data and reduce database queries.

Memcached is a simple, distributed key-value cache that stores everything as strings in memory, while Redis supports a wider range of data structures including lists, sets, sorted sets, and hashes. Redis also offers persistence options, pub/sub messaging, and built-in replication, making it a more general-purpose data store, whereas Memcached is focused purely on high-speed caching.

No, Memcached stores all data in RAM and does not provide built-in persistence to disk by design. If the Memcached server restarts or crashes, all cached data is lost, which is acceptable for a cache because the data can always be regenerated from the underlying database.

Memcached has client libraries available for virtually every major programming language, including Python, Java, PHP, Ruby, Perl, C#, Go, and Node.js. The server itself communicates using a simple text-based protocol, which has contributed to the rapid development of clients across diverse technology stacks.