Object Locking

It might not previously have been clear, but with the new designs, locking of objects become important. With an increasing number of systems wanting to change and edit our objects, being able to change an object without anyone else overwriting your changes becomes important.

There is a number of systems for locking, that can easily be adapted.

Hazelcast http://www.hazelcast.com/products-community.jsp is interesting, if you hold a datastructure, that multiple clients might want to change. It is based around a peer to peer model. It should be atomic enough for locking

Zookeeper is the hadoop service that is used to ensure that certain data is available to all nodes and processes. It can easily scale to multiple heads if the load increases, and should work for our purposes.

Memcached is a memory cache, as the name implies. Multiple clients can easily use the datastructure with very little overhead