What is MemcacheDB?
*******************
MemcacheDB is a distributed key-value storage system designed for persistence. It is NOT a cache solution, but a persistent storage engine for fast and reliable key-value based object storage and retrieval. It conforms to memcache protocol(not completed, see below), so any memcached client can have connectivity with it. MemcacheDB uses OpenLDAP MDB as a storing backend, which provides full
transaction support.

Features
********
* High performance read/write for a key-value based object
* High reliable persistent storage with transaction
* Memcache protocol compatibility

Supported memcache commands
***************************
get(also mutiple get) 
set, add, replace
append/prepend
incr, decr
delete
stats

Private commands
****************
rget
db_checkpoint

Some Warning
************
Expire time has been discarded in MemcacheDB(we are for persistence:p), so you should not use any corresponding features of clients. The daemon does nothing while you give a expire time to an item.

For more info, see: https://github.com/LMDB/memcachedb