The “12 factor app” was written in 2011 and became a widely cited classic of useful patterns for application architecture. #6 on the list said: apps shall be stateless.
There is some question as to whether this made sense even at the time it was written – some suggest it was simply declaring state to be someone else’s problem.
Containers have been rapidly evolving since – Docker was released 2 years later. In a rapidly advancing field, design patterns should be periodically challenged.
Open source projects have been adding features specifically intended to allow the pets (stateful) to be hosted alongside the cattle (stateless). The Kubernetes StatefulSet is one example.
This talk will survey currently available support and best practices for running stateful services on popular open source platforms. Proposals and works-in-progress will also be covered.
