[ https://issues.apache.org/jira/browse/YARN-2996?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14267322#comment-14267322 ]
Zhijie Shen commented on YARN-2996: ----------------------------------- My bad. I mean MemoryRMStateStore#updateRMDelegationTokenState. It contains two other synchronized methods, but it's better to keep them atomic, and not interpolated by other operations. > Refine some fs operations in FileSystemRMStateStore to improve performance > -------------------------------------------------------------------------- > > Key: YARN-2996 > URL: https://issues.apache.org/jira/browse/YARN-2996 > Project: Hadoop YARN > Issue Type: Improvement > Components: resourcemanager > Reporter: Yi Liu > Assignee: Yi Liu > Attachments: YARN-2996.001.patch, YARN-2996.002.patch > > > In {{FileSystemRMStateStore}}, we can refine some fs operations to improve > performance: > *1.* There are several places invoke {{fs.exists}}, then > {{fs.getFileStatus}}, we can merge them to save one RPC call > {code} > if (fs.exists(versionNodePath)) { > FileStatus status = fs.getFileStatus(versionNodePath); > {code} > *2.* > {code} > protected void updateFile(Path outputPath, byte[] data) throws Exception { > Path newPath = new Path(outputPath.getParent(), outputPath.getName() + > ".new"); > // use writeFile to make sure .new file is created atomically > writeFile(newPath, data); > replaceFile(newPath, outputPath); > } > {code} > The {{updateFile}} is not good too, it write file to _output\_file_.tmp, then > rename to _output\_file_.new, then rename it to _output\_file_, we can reduce > one rename operation. > Also there is one unnecessary import, we can remove it. -- This message was sent by Atlassian JIRA (v6.3.4#6332)