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https://issues.apache.org/jira/browse/YARN-3066?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14561130#comment-14561130
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Alan Burlison commented on YARN-3066:
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Yes, that's a good point about not every platform having libhadoop. Solaris for
example has the syscall but not the executable, so in that case it's a better
solution to use the syscall but that's not always going to be the case.
> Hadoop leaves orphaned tasks running after job is killed
> --------------------------------------------------------
>
> Key: YARN-3066
> URL: https://issues.apache.org/jira/browse/YARN-3066
> Project: Hadoop YARN
> Issue Type: Bug
> Components: nodemanager
> Environment: Hadoop 2.4.1 (probably all later too), FreeBSD-10.1
> Reporter: Dmitry Sivachenko
>
> When spawning user task, node manager checks for setsid(1) utility and spawns
> task program via it. See
> hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/DefaultContainerExecutor.java
> for instance:
> String exec = Shell.isSetsidAvailable? "exec setsid" : "exec";
> FreeBSD, unlike Linux, does not have setsid(1) utility. So plain "exec" is
> used to spawn user task. If that task spawns other external programs (this
> is common case if a task program is a shell script) and user kills job via
> mapred job -kill <Job>, these child processes remain running.
> 1) Why do you silently ignore the absence of setsid(1) and spawn task process
> via exec: this is the guarantee to have orphaned processes when job is
> prematurely killed.
> 2) FreeBSD has a replacement third-party program called ssid (which does
> almost the same as Linux's setsid). It would be nice to detect which binary
> is present during configure stage and put @SETSID@ macros into java file to
> use the correct name.
> I propose to make Shell.isSetsidAvailable test more strict and fail to start
> if it is not found: at least we will know about the problem at start rather
> than guess why there are orphaned tasks running forever.
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