memcachedb

What is Memcachedb?

Memcachedb is a distributed storage system designed for persistent. We simplely hacked from memcached and tugela. But neither of them. Memcachedb is not a cache solution, it is a persistent solution for high-frequency writing and reading. It conforms to memcache protocol(not completed, see below), so any memcached client can have connectivity with it. Memcachedb uses Berkeley DB as a storing backend, so lots of features including transaction and replication are supported.

Memcachedb Features

• High network performance, thanks to memcached and libevent(we using epoll).
• High storage performance, Using Berkeley DB BTREE Access Method, and bdb's own MPOOL.
• High availability, Berkeley DB Transaction supported, and replication is ready.

Supported memcache command

• get, set, add, replace
• incr, decr
• delete
• stats
• flush_all

Private commands

• db_checkpoint, db_archive
• db_ismaster, db_whoismaster (for replication)

We Stand on the shoulders of giants, Memcachedb source code is based on:

• Memcached: http://www.danga.com/memcached/
• Tugela: http://meta.wikimedia.org/wiki/Tugela_Cache