[
https://issues.apache.org/jira/browse/MAPREDUCE-2374?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13421196#comment-13421196
]
Colin Patrick McCabe commented on MAPREDUCE-2374:
-------------------------------------------------
Thanks for the strace output, Shrinivas. Unfortunately, it doesn't seem to
show the place where you're opening up
/local5/sj_mrv1_trunk/hadoop-local/ttprivate/taskTracker/root/jobcache/job_201207131350_0001/attempt_201207131350_0001_m_000201_0/taskjvm.sh
for writing.
If there is no file descriptor leak, you'd expect to see something like this:
{code}
open("blahblahblah.sh", {st_mode=S_IFREG|0700, ...}) = 5
close(5) = 0
...
execve("blahblahblah.sh") ...
{code}
On the other hand, if there is a leak, there should be no corresponding close()
call. Things can get more complicated than that because of dup() and stuff
like that, but that's the basic idea...
In the absence of that, we can't really draw any conclusions either way. It
may be helpful to use strace -f to follow forks. I realize there's a lot of
output, but those are the lines we need, I think.
> 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.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
