Remove release
handler from scheduler
#5091
Closed
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This removes the redundant handler
Scheduler.handle_release_data
. This handler was only used by a single code path on the worker side which is triggered during aWorker.steal_request
. There is a subtle race condition going on which looks like thisBob
receivessteal_request
withAlice
as intendedThief
steal_request
msg is queued up on scheduler / in flight / beinghandled * by
Bob
Alice
dies :(Bob
hasn't replied, yet, Scheduler thinks the task is lost and reschedules it, assigning it toBob
Bob
tocompute-task
Bob
released the key and notifies the scheduler that it released the keyBob
is already processing the task when it runs this handlerThis is not a critical race condition but it is not nice and I don't know if this couldn't escalate to something worse.
More importantly, this handler and stimulus include a lot of dead code. At some point this surely had a meaning but it was lost by now.
There are also seemingly duplicate implementations in
Scheduler.handle_missing_data
andScheduler.release_worker_data
which are still in use.