thinkharderdev opened a new pull request, #511: URL: https://github.com/apache/arrow-ballista/pull/511
# Which issue does this PR close? <!-- We generally require a GitHub issue to be filed for all bug fixes and enhancements and this helps us generate change logs for our releases. You can link an issue to this PR using the GitHub syntax. For example `Closes #123` indicates that this PR will close issue #123. --> Closes #504 Depends on https://github.com/apache/arrow-ballista/pull/504 # Rationale for this change <!-- Why are you proposing this change? If this is already explained clearly in the issue then this section is not needed. Explaining clearly why changes are proposed helps reviewers understand your changes and offer better suggestions for fixes. --> Track the size of the pending task queue in the scheduler and expose through both prometheus metrics and the external scaler service. The number of pending tasks is the number of tasks that can be scheduled but for which there is no executor slot to schedule it on (i.e. it does not count tasks for unresolved stages, etc). # What changes are included in this PR? <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> Add a `pending_tasks` state to the `QueryStageScheduler` and track the value in response to scheduler events. I also added some more bells and whistles to the `SchedulerTest` utility introduced in the previous PR. We can now submit a job and control when "virtual" executors send their task updates so we have finer-grained control to test different scenarios. # Are there any user-facing changes? <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> The external scaler service should now return the actual number of pending tasks instead of a hard-coded value. Also, the pending task queue size should be available in the prometheus metrics. <!-- If there are any breaking changes to public APIs, please add the `api change` label. --> No -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
