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https://issues.apache.org/jira/browse/HADOOP-7256?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13039840#comment-13039840
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Todd Lipcon commented on HADOOP-7256:
-------------------------------------
- looks like there are some hard tabs, please configure your editor to use
spaces per our coding guidelines
- in the newly added LOG.debug line, please include some text. eg
LOG.debug("Ignoring error closing socket", ignored);
- in the test case, please add a fail("Didn't throw") line after the
IOUtils.copyBytes call. That will make sure that the exception is properly
propagated and not swallowed.
- Probably better to separate the test in two -- one for the case where the
inputstream throws, and another for the case when the output stream throws.
> Resource leak during failure scenario of closing of resources.
> ---------------------------------------------------------------
>
> Key: HADOOP-7256
> URL: https://issues.apache.org/jira/browse/HADOOP-7256
> Project: Hadoop Common
> Issue Type: Bug
> Affects Versions: 0.20.2, 0.21.0
> Reporter: ramkrishna.s.vasudevan
> Priority: Minor
> Fix For: 0.23.0
>
> Attachments: HADOOP-7256-patch-1.patch
>
> Original Estimate: 8h
> Remaining Estimate: 8h
>
> Problem Statement:
> ===============
> There are chances of resource leak and stream not getting closed
> Take the case when after copying data we try to close the Input and output
> stream followed by closing of the socket.
> Suppose an exception occurs while closing the input stream(due to runtime
> exception) then the subsequent operations of closing the output stream and
> socket may not happen and there is a chance of resource leak.
> Scenario
> =======
> During long run of map reduce jobs, the copyFromLocalFile() api is getting
> called.
> Here we found some exceptions happening. As a result of this we found the
> lsof value raising leading to resource leak.
> Solution:
> =======
> While doing a close operation of any resource catch the RuntimeException also
> rather than catching the IOException alone.
> Additionally there are places where we try to close a resource in the catch
> block.
> If this close fails, we just throw and come out of the current flow.
> In order to avoid this, we can carry out the close operation in the finally
> block.
> Probable reasons for getting RunTimeExceptions:
> =====================================
> We may get runtime exception from customised hadoop streams like
> FSDataOutputStream.close() . So better to handle RunTimeExceptions also.
>
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