[Core] Fix test_no_worker_child_process_leaks #35840
Merged
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Why are these changes needed?
Thanks @iycheng for debugging this!
In #33976 we don't always guarantee that children of worker processes are killed -- namely if the worker dies in an unexpected way, they are not (see #26118).
This unfortunately happens in the
test_no_worker_child_process_leaks
test case since the Ray cluster is torn down when the driver exits, which can lead to worker processes being forcefully terminated [the solution in this PR is to not initialize the Ray cluster in the driver script but start a separate head node with.add_node
].As a result of this forceful killing, the test becomes flaky (it passes if the workers are killed through the normal termination, and it doesn't pass if the workers are killed otherwise). The flakiness is not super big right now but becomes big with some other changes.
This should eventually be fixed with #26118.
Related issue number
Checks
git commit -s
) in this PR.scripts/format.sh
to lint the changes in this PR.method in Tune, I've added it in
doc/source/tune/api/
under thecorresponding
.rst
file.