As described in an earlier post Memcached is an extremely popular caching layer used in most big web properties and we’re adding the ability to access MySQL Cluster directly using the familiar Memcached key-value/NoSQL API without needing to go through the MySQL Server. There is a huge amount of flexibility built into this solution – including:

• Decide what data should be held only in the Memcached server; what should be written straight through to MySQL Cluster and then discarded  and what data should be cached in Memcached but persisted in MySQL Cluster
• Where data is held both in Cluster and the Memcached server, they can automatically be kept in sync
• By default it’s completely schema-less, all key-value pairs will be transparently stored in a single table within MySQL Cluster behind the scenes
• Can map key-prefixes to columns in MySQL Cluster tables – allowing simultaneous access to the same data using SQL.