[rb2k_]

It used to be that parallel tests bundled up the tasks in "groups" and went one group at a time. e.g. 12 tests on 4 cores ==> 4 groups with 3 tests each.

The problem was that some of the groups might have ended up with tests that take 5 minutes each (finished after 15 minutes) and other groups end up with the 20 second ones (finished after 1 minute). Did that balancing every change?

Another question: How does this work for different RSpec formatters? (specifically: junit xml output or html output). Will it still result in a single file?

[jacques_chester]

And just like that, we're on the cusp of reinventing batch scheduling! :D

In all seriousness though, I think that a look at OS scheduling would provide useful inspiration for test scheduling.

[rb2k_]

Just a queue that forks processes would work fine, no need to get into OS details :D