Eventual consistency

http://en.wikipedia.org/wiki/Eventual_consistency


Eventual consistency is a consistency model used in distributed computing that informally guarantees that, if no new updates are made to a given data item, eventually all accesses to that item will return the last updated value.

In order to ensure replica convergence, a system must reconcile differences between multiple copies of distributed data. This process, often known as anti-entropy, requires exchanging versions of data between servers.