[dtornow]

My favorite mental framework to reason about consistency in distributed systems, Invariant Confluence, was formulated by Peter Bailis at al in Coordination Avoidance in Database Systems (overview and link to paper http://www.bailis.org/blog/when-does-consistency-require-coo...)

Invariant confluence, determines whether an application requires coordination for correct execution.

You can tailor the invariants to your requirements making invariant confluence a much better tool than CAP