JiaLiangC opened a new pull request, #6373: URL: https://github.com/apache/hadoop/pull/6373
<!-- Thanks for sending a pull request! 1. If this is your first time, please read our contributor guidelines: https://cwiki.apache.org/confluence/display/HADOOP/How+To+Contribute 2. Make sure your PR title starts with JIRA issue id, e.g., 'HADOOP-17799. Your PR title ...'. --> ### Description of PR https://issues.apache.org/jira/browse/HDFS-17287 Here's the translation of the Hadoop PR description into English: **Hadoop Parallel Compilation Submission Logic** 1. Reasons for Parallel Compilation Failure - In sequential compilation, as modules are compiled one by one in order, there are no errors because the compilation follows the module sequence. - However, in parallel compilation, all modules are compiled simultaneously. The compilation order during multi-module concurrent compilation depends on the inter-module dependencies. If Module A depends on Module B, then Module B will be compiled before Module A. This ensures that the compilation order follows the dependencies between modules. But when Hadoop compiles in parallel, for example, compiling `hadoop-yarn-project`, the dependencies between modules are correct. The issue arises during the dist package stage. `dist` packages all other compiled modules. **Behavior of `hadoop-yarn-project` in Serial Compilation:** - In serial compilation, it compiles modules in the pom one by one in sequence. After all modules are compiled, it compiles `hadoop-yarn-project`. During the `prepare-package` stage, the `maven-assembly-plugin` plugin is executed for packaging. All packages are repackaged according to the description in `hadoop-assemblies/src/main/resources/assemblies/hadoop-yarn-dist.xml`. **Behavior of `hadoop-yarn-project` in Parallel Compilation:** - Parallel compilation compiles modules according to the dependency order among them. If modules do not declare dependencies on each other through `dependency`, they are compiled in parallel. According to the dependency definition in the pom of `hadoop-yarn-project`, the dependencies are compiled first, followed by `hadoop-yarn-project`, executing its `maven-assembly-plugin`. - However, the files needed for packaging in `hadoop-assemblies/src/main/resources/assemblies/hadoop-yarn-dist.xml` are not all included in the `dependency` of `hadoop-yarn-project`. Therefore, when compiling `hadoop-yarn-project` and executing `maven-assembly-plugin`, not all required modules are built yet, leading to errors in parallel compilation. **Solution:** - The solution is relatively straightforward: organize all modules from `hadoop-assemblies/src/main/resources/assemblies/hadoop-yarn-dist.xml`, and then declare them as dependencies in the pom of `hadoop-yarn-project`. ### How was this patch tested? manual test on centos8 ![image](https://github.com/apache/hadoop/assets/18082602/2f95c1df-6aeb-42fd-98d8-7fe9e47e9401) ### For code changes: - [ ] Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')? - [ ] Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation? - [ ] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under [ASF 2.0](http://www.apache.org/legal/resolved.html#category-a)? - [ ] If applicable, have you updated the `LICENSE`, `LICENSE-binary`, `NOTICE-binary` files? -- 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: common-issues-unsubscr...@hadoop.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org