wangyang0918 opened a new pull request #10143: [FLINK-13184]Starting a TaskExecutor blocks the YarnResourceManager's main thread URL: https://github.com/apache/flink/pull/10143 <!-- *Thank you very much for contributing to Apache Flink - we are happy that you want to help us improve Flink. To help the community review your contribution in the best possible way, please go through the checklist below, which will get the contribution into a shape in which it can be best reviewed.* *Please understand that we do not do this to make contributions to Flink a hassle. In order to uphold a high standard of quality for code contributions, while at the same time managing a large number of contributions, we need contributors to prepare the contributions well, and give reviewers enough contextual information for the review. Please also understand that contributions that do not follow this guide will take longer to review and thus typically be picked up with lower priority by the community.* ## Contribution Checklist - Make sure that the pull request corresponds to a [JIRA issue](https://issues.apache.org/jira/projects/FLINK/issues). Exceptions are made for typos in JavaDoc or documentation files, which need no JIRA issue. - Name the pull request in the form "[FLINK-XXXX] [component] Title of the pull request", where *FLINK-XXXX* should be replaced by the actual issue number. Skip *component* if you are unsure about which is the best component. Typo fixes that have no associated JIRA issue should be named following this pattern: `[hotfix] [docs] Fix typo in event time introduction` or `[hotfix] [javadocs] Expand JavaDoc for PuncuatedWatermarkGenerator`. - Fill out the template below to describe the changes contributed by the pull request. That will give reviewers the context they need to do the review. - Make sure that the change passes the automated tests, i.e., `mvn clean verify` passes. You can set up Travis CI to do that following [this guide](https://flink.apache.org/contributing/contribute-code.html#open-a-pull-request). - Each pull request should address only one issue, not mix up code from multiple issues. - Each commit in the pull request has a meaningful commit message (including the JIRA id) - Once all items of the checklist are addressed, remove the above text and this checklist, leaving only the filled out template below. **(The sections below can be removed for hotfixes of typos)** --> ## What is the purpose of the change Currently, YarnResourceManager starts all task executors in main thread. This could cause RM to become unresponsive when launching a large number of TEs (e.g. > 1000) because it involves blocking I/O operations (writing files to HDFS, communicating with the node manager using a synchronous NMClient). We could do the following two optimizations: * Use the NMClientAsync for the communication with Yarn's NodeManager * Don't upload files (avoid blocking file system operations), use dynamic properties instead ## Brief change log * Use NMClientAsync instead of NMClient to avoid starting TaskExecutor blocking call. * Use dynamic properties instead of uploading taskmanager-conf.yaml to hdfs. ## Verifying this change * The changes could be covered by the existing test. All the unit tests, integrated tests and e2e should pass. * Manually check with large scale, more than 5000 containers. ## Does this pull request potentially affect one of the following parts: - Dependencies (does it add or upgrade a dependency): (no) - The public API, i.e., is any changed class annotated with `@Public(Evolving)`: (no) - The serializers: (no) - The runtime per-record code paths (performance sensitive): (no) - Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (yes) - The S3 file system connector: (no) ## Documentation - Does this pull request introduce a new feature? (no) - If yes, how is the feature documented? (not applicable)
---------------------------------------------------------------- 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
