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https://issues.apache.org/jira/browse/MAPREDUCE-2374?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13421198#comment-13421198
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Colin Patrick McCabe commented on MAPREDUCE-2374:
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I just thought of something. Suppose that the JVM is holding blahblahblah.sh
open for write, and meanwhile another thread forks a bash process (or
something). After the fork completes, that process will hold blahblahblah.sh
open for write with O_WRONLY. At the very least, this is a race condition that
could lead to "mysterious" failures, since you don't know when the fork'ed
process will next get scheduled in relation to the parent process.
The O_CLOEXEC flag was introduced in Linux 2.6.23 to solve this problem, by
atomically closing the FDs on a fork. However, I didn't see it being used in
the strace output you posted. And it's certainly not around on RHEL5 and
earlier.
If this is true, then I guess the solution Andy posted earlier is probably the
best way to go. Just get rid of the -c and this behavior will be masked.
> Should not use PrintWriter to write taskjvm.sh
> ----------------------------------------------
>
> Key: MAPREDUCE-2374
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2374
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Affects Versions: 0.22.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Fix For: 0.22.1
>
> Attachments: failed_taskjvmsh.strace, mapreduce-2374-on-20sec.txt,
> mapreduce-2374.txt, mapreduce-2374.txt, successfull_taskjvmsh.strace
>
>
> Our use of PrintWriter in TaskController.writeCommand is unsafe, since that
> class swallows all IO exceptions. We're not currently checking for errors,
> which I'm seeing result in occasional task failures with the message "Text
> file busy" - assumedly because the close() call is failing silently for some
> reason.
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