clintropolis opened a new pull request #8116: remove unnecessary lock in ForegroundCachePopulator leading to a lot of contention URL: https://github.com/apache/incubator-druid/pull/8116 ### Description This PR adds a performance improvement to `ForegroundTaskRunner`, removing a synchronized block that appears to be unnecessary, since `CachePopulator` is shared by all processing threads but the lock covers bytes and json generator that are tied to a specific segment which should only be happening in a single thread. Observed a lot of time being spent in `ForegroundCachePopulator`, displayed in the following flame graph:  I don't have direct access to the cluster where these observations were made, so I don't have measurements for the fix, I will see if I can get some equivalent measurements done locally and update this ticket. <hr> This PR has: - [x] been self-reviewed. - [x] using the [concurrency checklist](https://github.com/apache/incubator-druid/blob/master/dev/code-review/concurrency.md)
---------------------------------------------------------------- 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] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
