rahulrane50 opened a new pull request, #2344: URL: https://github.com/apache/helix/pull/2344
### Issues - [X] My PR addresses the following Helix issues and references them in the PR description: Adds a new metric to report real time missing top state for any partition for each resource in a cluster. (#200 - Link your issue number here: You can write "Fixes #XXX". Please use the proper keyword so that the issue gets closed automatically. See https://docs.github.com/en/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue Any of the following keywords can be used: close, closes, closed, fix, fixes, fixed, resolve, resolves, resolved) ### Description Issue : Currently, if waged rebalancer is used then there could be a situation where multiple leader replicas are residing on same node. If that node goes down for maintainence or for any other reason then there is no current metric which reports about missing top state until any rebalancer event is triggered. Ask : Ask here is to add a metric which satisfies following conditions : 1. The metric should be at resource level and should be reported irrespective of top state replica is recovered or not for any partition of that resource. 2. This metric should be started as soon as "any" partition for a resource has top state missing and it should be "reset" only when that resource has no partition with missing top state. Solution : The solution proposed in this PR starts a async thread as soon as first partition of any resource has top state missing and it continuously increments a counter at resource level as long as that resource has "at least one" partition with missing top state. If there are no resources with any partitions with missing top state then this async thread will sleep. The counter reported by this thread is monotonically increasing and will be reset when all top state replicas for that resource are recovered. This number DOES NOT gives any insights about which partitions are missing top state or how many partitions are missing top state but non-zero value of this counter indicates that there are at least one partition for that resource has missing top state. - [ ] Here are some details about my PR, including screenshots of any UI changes: (Write a concise description including what, why, how) ### Tests - [X ] The following tests are written for this issue: CI pipeline and added new tests for verifying metrics. ``` mvn test -Dtest=TestTopStateHandoffMetrics [WARNING] Tests run: 12, Failures: 0, Errors: 0, Skipped: 1, Time elapsed: 18.723 s - in org.apache.helix.monitoring.mbeans.TestTopStateHandoffMetrics [INFO] [INFO] Results: [INFO] [WARNING] Tests run: 12, Failures: 0, Errors: 0, Skipped: 1 ``` (List the names of added unit/integration tests) - The following is the result of the "mvn test" command on the appropriate module: (If CI test fails due to known issue, please specify the issue and test PR locally. Then copy & paste the result of "mvn test" to here.) ### Changes that Break Backward Compatibility (Optional) - My PR contains changes that break backward compatibility or previous assumptions for certain methods or API. They include: (Consider including all behavior changes for public methods or API. Also include these changes in merge description so that other developers are aware of these changes. This allows them to make relevant code changes in feature branches accounting for the new method/API behavior.) ### Documentation (Optional) - In case of new functionality, my PR adds documentation in the following wiki page: (Link the GitHub wiki you added) ### Commits - My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "[How to write a good git commit message](http://chris.beams.io/posts/git-commit/)": 1. Subject is separated from body by a blank line 1. Subject is limited to 50 characters (not including Jira issue reference) 1. Subject does not end with a period 1. Subject uses the imperative mood ("add", not "adding") 1. Body wraps at 72 characters 1. Body explains "what" and "why", not "how" ### Code Quality - My diff has been formatted using helix-style.xml (helix-style-intellij.xml if IntelliJ IDE is used) -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
