hadoop-pig-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Daniel Dai (JIRA)" <j...@apache.org>
Subject [jira] Commented: (PIG-1313) PigServer leaks memory over time
Date Thu, 25 Mar 2010 18:15:27 GMT

    [ https://issues.apache.org/jira/browse/PIG-1313?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12849811#action_12849811
] 

Daniel Dai commented on PIG-1313:
---------------------------------

I think ThreadLocal could be a simpler alternative solution for now. In the long term, we
should move static FileLocalizer variable into PigServer, since user may not launch different
thread for different PigServer, ThreadLocal can not solve all situation. But moving static
variables require more code changes. So I am fine to use ThreadLocal for now if it solves
Bill's problem. Hi, Bill, can you give a patch on this?

> PigServer leaks memory over time
> --------------------------------
>
>                 Key: PIG-1313
>                 URL: https://issues.apache.org/jira/browse/PIG-1313
>             Project: Pig
>          Issue Type: Bug
>            Reporter: Bill Graham
>         Attachments: Pig1313Reproducer.java
>
>
> When {{PigServer}} runs it creates temporary files using the {{FileLocalizer.getTemporaryPath(..)}}.
This static method creates and returns a handle to a temporary file (as an instance of {{ElementDescriptor}}).
The {{ElementDescriptors}} returned by this method are kept on a static {{Stack}} named {{toDelete}}.
The items on {{toDelete}} get removed by the {{FileLocalizer.deleteTempFile()}} method.
> The only place in the code where I see {{FileLocalizer.deleteTempFile()}} called is in
the Main class. {{PigServer}} does not call that method though, so a long-running VM that
repeatedly uses instances of {{PigServer}} to run jobs will leak memory via {{toDelete}}.
> One suggested fix is to have {{PigServer.shutdown()}} call {{FileLocalizer.deleteTempFile()}},
but this would cause problems in a multi-threaded environment, since it seems {{ElementDescriptors}}
are pushed onto the {{toDelete}} stack before they're used, not once they're done with. With
this approach, running multiple instances of {{PigServer}} in separate threads could cause
one completed job to clobber the other's still-in-use temp files.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message