In 2011, Ken Rugg and I were having a number of conversations around CAP Theorem and after much discussion, we came up with the following succinct inequality. It was able to help us much better speak to the issue of what constituted “availability”, “partition tolerance”, and “consistency”. It also confirmed our suspicions that availability and partition tolerance were not simple binary attributes; Yes or No, but rather that they had shades of gray.
So here’s the write-up we prepared at that time.
Unfortunately, the six part blog post that we wrote (on parelastic.com) never made it in the transition to the new owners.