weizuo93 opened a new pull request #4670: URL: https://github.com/apache/incubator-doris/pull/4670
## Proposed changes Currently, there are M threads to do base compaction and N threads to do cumulative compaction for each disk. Too many compaction tasks may run out of memory, so the max concurrency of running compaction tasks is limited by semaphore. If the running threads cost too much memory, we can't defense it. In addition, reducing concurrency to avoid OOM will lead to some compaction tasks can't be executed in time and we may encounter more heavy compaction. Therefore, concurrency limitation is not enough. The strategy proposed in #3624 may be effective to solve the OOM. A CompactionPermitLimiter is used for compaction limitation, and use single-producer/multi-consumer model. Producer will try to generate compaction tasks and acquire `permits` for each task. The compaction task which can hold `permits` will be executed in thread pool and each finished task will release its `permits`. `permits` should be applied for before a compaction task can execute. When the sum of `permits` held by executing compaction tasks reaches a threshold, subsequent compaction task will be no longer allowed, until some `permits` are released. Tablet compaction score is used as `permits` of compaction task here. To some extent, memory consumption can be limited by setting appropriate `permits` threshold. ## Types of changes What types of changes does your code introduce to Doris? _Put an `x` in the boxes that apply_ - [] Bugfix (non-breaking change which fixes an issue) - [x] New feature (non-breaking change which adds functionality) - [] Breaking change (fix or feature that would cause existing functionality to not work as expected) - [] Documentation Update (if none of the other choices apply) - [x] Code refactor (Modify the code structure, format the code, etc...) ## Checklist _Put an `x` in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code._ - [x] Issue (Fix #3624)have described the bug/feature there in detail - [x] Compiling and unit tests pass locally with my changes - [] I have added tests that prove my fix is effective or that my feature works - [] If this change need a document change, I have updated the document - [x] Any dependent changes have been merged ---------------------------------------------------------------- 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]
