Distributed Systems and Strong (Eventual) Consistency, Michael Carney

Distributed Systems and Strong (Eventual) Consistency

DevconTLV June 2015 Conference, Monday, June 22, 2015, 15:05

A review of the CAP Theorem and the difficulties of resolving conflicts in highly distributed and highly available systems. This talk covers the issues and various theories on how to discover and resolve conflicts 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 synchronization. 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

Michael Carney

Dir. Sales Southern Europe

Basho

Michael has been working with data and databases since the stone age. Starting with Informix in an RTOS environment, Michael migrated to Sybase, SQLServer, Raima’s Velocis and then MySQL where he built the MySQL France team and then lead the Southern European team until acquisition by Oracle at which point he helped found MariaDB Corporation. After four years at MariaDB he thought he’d take a look at this NoSQL thing that everyone was talking about and ended up at Basho working with Riak.

British by birth, Michael completed his studies in Computer Science at Bordeaux University and, due to a weakness for fine wines and cheeses, has never achieved escape velocity from France in the 25 years since he graduated. He lives between Paris and the Loire Valley with his American wife and their two culturally confused children.