Comment 5 for bug 1768077

I think the problem here is that in order to test the scrubber restore, there can only be one instance of the scrubber running, and in the current functional test environment, with tests running in parallel, you can't guarantee that. So the wait_for_scrubber_shutdown just keeps trying to run the test until the command goes through. I think a better way to do this would be to run these tests in serial mode. I think you can do this by putting the tests that can't be run in a concurrent environment into their own test class. Then we'd run the functional tests normally, but pass an argument to stestr blacklisting the serial test. After the "regular" functional tests were run, there would be a second command to run only the sequential class. It looks from the docs that there's a way to tell stestr to combine the output from the two runs into a single result.

Matt Treinish is the author of stestr, so maybe we can reach out to him for help.