Hi Pratibha, if you need replication i have written memcached-like server which supports same operations, plus it has built-in replication and snapshots based on MVCC. Basically it works the same way but algorithms are different (main point is when there are large differences between TTLs of keys it'll use much less memory because it keeps expiration times in separated memory area and reclaim algorithm works totally differently).
So that's not like memcached driver, just something if you need replicated K/V store which is compatible with memcached (compatible = supports same operations, not has same protocol)