CAP confusion: Problems with Partition Tolerance

Over on the Cloudera blog I’ve written an article that should be of interest to readers of this blog.

I’m no great fan of the ubiquity of the CAP theorem - it’s a solid impossibility result which appeals to the theorist in me, but it doesn’t capture every fundamental tension in a distributed system. For example: we make our systems distributed across more than one machine usually for reasons of performance and to eliminate a single point of failure. Neither of these motivations are captured verbatim by the CAP theorem. There’s more to designing distributed systems!

In this, I agree with Stonebraker; it’s the erroneous representation of ‘partition tolerance’ that I found very strange. I’ve been a good deal more forceful in private about this than I have in public 🙂