Talk by Gordon Guthrie, Senior Software Engineer at Basho.
A review of the CAP Theorem and the difficulties of resolving conflicts in highly distributed systems. Covering the issues and various theories on how to resolve including the use CRDTs in Riak
CRDTs are used to replicate data across multiple computers in a network, executing updates without the need for remote synchronisation. This leads to merge conflicts in systems using conventional eventual consistency technology, but CRDTs are designed such that conflicts are mathematically impossible. Under the constraints of the CAP theorem they provide the strongest consistency guarantees for available/partition-tolerant (AP) settings.
The CRDT concept was first formally defined in 2007 by Marc Shapiro and Nuno Preguiça in terms of operation commutativity, and development was initially motivated by collaborative text editing. The concept of semilattice evolution of replicated states was first defined by Baquero and Moura in 1997, and development was initially motivated by mobile computing. The two concepts were later unified in 2011.
Basho has worked with the EU and Marc Shapiro's team to push CRDTs into distributed systems. Riak v2.x is the first commercial product to include this functionality