CAP Theorem: Two out of three ain't right

Trends in Architecture and Design
23 April 1:20pm - 2:10pm @ Ballroom C

The popular understanding of Eric Brewer's CAP Theorem is that in distributed systems it is only possible to support two out of three desired properties: consistency, availability and partition tolerance. The 'two out of three' explanation of CAP Theorem has been used in recent years to explain and justify the emergence of NoSQL databases that relax consistency in favour of high availability. It has likewise been used to question the validity of claims that NewSQL databases are able to deliver both highly available distributed architecture and support ACID transactions.

How is possible for NewSQL databases - including many based on MySQL - to provide strongly consistent distributed systems and not break CAP Theorem? In this presentation Matt Aslett, research manager at 451 Research, will examine the evidence from a variety of experts, including Eric Brewer himself, to argue that the 'two out of three' explanation of CAP Theorem is misleading, and present examples of projects and products that prove it is possible to support consistency, availability and partition tolerance, and still be compatible with CAP Theorem.


Matt Aslett
Research Director, Data Management and Analytics, 451 Research
As research director for data management and analytics within 451 Research's Information Management practice, Matt has overall responsibility for the coverage of operational and analytic databases, data integration, data quality, and business intelligence. Matt's own primary area of focus is on relational and non-relational databases, data warehousing, data caching, and Hadoop. Matt is also an expert in open source software and regularly contributes to 451 Research's open source-related research. Prior to joining The 451 Group, Matt was Deputy Editor of monthly magazine Computer Business Review and ComputerWire's daily news service. Matt started in IT journalism in 1997 as a staff writer with monthly magazine Unix and NT News, where he became editor in 2000. He has also contributed to a number of other publications. Matt holds a BA in Multimedia Journalism from Bournemouth University in the UK.