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Chandni Singh edited comment on YARN-9839 at 9/18/19 3:58 AM: -------------------------------------------------------------- Caching {{LocalizerRunner}} which is a {{Thread}} is not a good idea. The intention to cache it seems because the {{LocalizerRunner}} holds the data as well which can only be released when the container resources have been localized (message is received from the respective ContainerLocalizer) {code} final Map<LocalResourceRequest,LocalizerResourceRequestEvent> scheduled; // Its a shared list between Private Localizer and dispatcher thread. final List<LocalizerResourceRequestEvent> pending; {code} This code needs to be modified so that the Thread itself is not cached but only the relevant information is cached. Right now the {{Thread}} object persists in memory until the localization of the container is done which can take much longer. was (Author: csingh): Caching {{LocalizerRunner}} which is a {{Thread}} is not a good idea. The intention to cache it seems because the {{LocalizerRunner}} holds the data as well which can only be released when the container resources have been localized (message is received from the respective ContainerLocalizer) {code} final Map<LocalResourceRequest,LocalizerResourceRequestEvent> scheduled; // Its a shared list between Private Localizer and dispatcher thread. final List<LocalizerResourceRequestEvent> pending; {code} This codes needs to be modified so that the Thread itself is not cached but only the relevant information is cached. Right now the {{Thread}} object persists in memory until the localization of the container is done which can take much longer. > NodeManager java.lang.OutOfMemoryError unable to create new native thread > ------------------------------------------------------------------------- > > Key: YARN-9839 > URL: https://issues.apache.org/jira/browse/YARN-9839 > Project: Hadoop YARN > Issue Type: Bug > Reporter: Chandni Singh > Assignee: Chandni Singh > Priority: Major > > NM fails with the below error even though the ulimit for NM is large. > {code} > 2019-09-12 10:27:46,348 ERROR org.apache.hadoop.util.Shell: Caught > java.lang.OutOfMemoryError: unable to create new native thread. One possible > reason is that ulimit setting of 'max user processes' is too low. If so, do > 'ulimit -u <largerNum>' and try again. > 2019-09-12 10:27:46,348 FATAL > org.apache.hadoop.yarn.YarnUncaughtExceptionHandler: Thread > Thread[LocalizerRunner for > container_e95_1568242982456_152026_01_000132,5,main] threw an Error. > Shutting down now... > java.lang.OutOfMemoryError: unable to create new native thread > at java.lang.Thread.start0(Native Method) > at java.lang.Thread.start(Thread.java:717) > at org.apache.hadoop.util.Shell.runCommand(Shell.java:562) > at org.apache.hadoop.util.Shell.run(Shell.java:482) > at > org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:776) > at org.apache.hadoop.util.Shell.execCommand(Shell.java:869) > at org.apache.hadoop.util.Shell.execCommand(Shell.java:852) > at org.apache.hadoop.fs.FileUtil.execCommand(FileUtil.java:1097) > at > org.apache.hadoop.fs.RawLocalFileSystem$DeprecatedRawLocalFileStatus.loadPermissionInfo(RawLocalFileSystem.java:659) > at > org.apache.hadoop.fs.RawLocalFileSystem$DeprecatedRawLocalFileStatus.getPermission(RawLocalFileSystem.java:634) > at > org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService.checkLocalDir(ResourceLocalizationService.java:1441) > at > org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService.getInitializedLocalDirs(ResourceLocalizationService.java:1405) > at > org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService.access$800(ResourceLocalizationService.java:140) > at > org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService$LocalizerRunner.run(ResourceLocalizationService.java:1114) > {code} > For each container localization request, there is a {{LocalizerRunner}} > thread created and each {{LocalizerRunner}} creates another thread to get > file permission info which is where we see this failure from. It is in > Shell.java -> {{runCommand()}} > {code} > Thread errThread = new Thread() { > @Override > public void run() { > try { > String line = errReader.readLine(); > while((line != null) && !isInterrupted()) { > errMsg.append(line); > errMsg.append(System.getProperty("line.separator")); > line = errReader.readLine(); > } > } catch(IOException ioe) { > LOG.warn("Error reading the error stream", ioe); > } > } > }; > {code} > {{LocalizerRunner}} are Threads which are cached in > {{ResourceLocalizationService}}. Looking into a possibility if they are not > getting removed from the cache. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org