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https://issues.apache.org/jira/browse/HIVE-4574?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13724693#comment-13724693
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Thejas M Nair commented on HIVE-4574:
-------------------------------------

bq, I was wondering why none of the other methods which use XMLEncoder are not 
synchronized as well. 
I had a brief look at the OpenJDK code again, I could not find a reason why I 
might not have synchronized other calls to XMLEncoder. It was probably an 
oversight.


                
> XMLEncoder thread safety issues in openjdk7 causes HiveServer2 to be stuck
> --------------------------------------------------------------------------
>
>                 Key: HIVE-4574
>                 URL: https://issues.apache.org/jira/browse/HIVE-4574
>             Project: Hive
>          Issue Type: Bug
>          Components: HiveServer2
>    Affects Versions: 0.11.0
>            Reporter: Thejas M Nair
>            Assignee: Thejas M Nair
>         Attachments: HIVE-4574.1.patch
>
>
> In open jdk7, XMLEncoder.writeObject call leads to calls to 
> java.beans.MethodFinder.findMethod(). MethodFinder class not thread safe 
> because it uses a static WeakHashMap that would get used from multiple 
> threads. See -
> http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/7-b147/com/sun/beans/finder/MethodFinder.java#46
> Concurrent access to HashMap implementation that are not thread safe can 
> sometimes result in infinite-loops and other problems. If jdk7 is in use, it 
> makes sense to synchronize calls to XMLEncoder.writeObject .

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