[otterley]

The most puzzling thing for me is why schedulers and executors are so tightly coupled in Mesos. In my mind, those are separate concerns: schedulers should concern themselves solely with locating an available resource for you (and should be part of the Mesos core), and the executor should take care of launching and managing the program to be run.

With the current design, if I want to launch a Docker container, I have to use its scheduler, even though its scheduler might not be as good as some other resource's scheduler. And I might have to accept a regression in the scheduler in order to benefit from a bugfix in the executor.