capistrant commented on pull request #10284: URL: https://github.com/apache/druid/pull/10284#issuecomment-721356289
> @capistrant Can we write integration tests for this dynamic config? Since it's not the default and used infrequently, I would hate for a refactoring to break this functionality and us not know about it Good point, @suneet-s. I like the idea of protecting this against regressions, but I'm wondering if there is the proper plumbing in place to make this easy to test as is. Wondering if you have any inputs/ideas on how it may be accomplished. We want to test the integration between the Coordinator's dynamic config and the act of balancing the cluster. Specifically, we want to ensure that our new config is being honored by Coordinator, meaning that balancing considers the expected % of segments when looking for segments to move. The easiest way I can think of is that we have our integration tests cluster with a known number of segments in it. We set the config to some low % and monitor to make sure that no coordination cycle involves more moves than the number of segments in the cluster * (the config value / 100). But what exactly would we monitor? The # of moves and segments let alone is logged by Druid currently. But do we really want to scrape logs? We could emit balancing stats and monitor the emitter. But not all balancer strategy implementations emit the proper fields, so we would need to modify that. Do you have any ideas that I may be overlooking? ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
