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https://issues.apache.org/jira/browse/DERBY-5552?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13176216#comment-13176216
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Brett Bergquist commented on DERBY-5552:
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If I disable the istat daemon, I still the the timeout but now the error is 
reported as it should and the transaction is aborted and my code continues.  
With the itstat deamon enabled, then the lock timeout is discovered and 
signaled by exception being thrown but between the time it gets caught and 
processed, the istat daemon has set the "isValid" property of the statement to 
"false".  The original lock timeout exception is caught but then the 

    Activation.checkStatementValidity()

is called in the exception handler.  This finds that the statement is not valid 
(isValid == false) and throws its own exception indicating that a recompilation 
is required, swallowing the original lock timeout exception in the process.  
This causes the existing statement to be rebuilt and re-executed but the locks 
are still present, the lock timeout will occur again, the lock timeout 
exception will be thrown, the istat daemon will set the "isValid" to false 
again, etc.  The process just continues forever.

The patch that I attached to the bug only calls

    Activation.checkStatementValidity()

in the exception handler if the caught exception is not set to REPORT_ALWAYS.  
This seem okay and to make sense because if the code is handling an exception 
that is to be REPORT_ALWAYS, there is no sense looking for a statement that is 
invalid; just report the exception.

                
> Derby threads hanging when using ClientXADataSource and a deadlock or lock 
> timeout occurs
> -----------------------------------------------------------------------------------------
>
>                 Key: DERBY-5552
>                 URL: https://issues.apache.org/jira/browse/DERBY-5552
>             Project: Derby
>          Issue Type: Bug
>          Components: Network Server
>    Affects Versions: 10.8.1.2
>         Environment: Solaris 10, Glassfish V2.1.1,
>            Reporter: Brett Bergquist
>            Priority: Blocker
>         Attachments: appserverstack.txt, client.tar.Z, derby.log, 
> derbystackatshutdown.txt, execute.patch, transactionsleft.txt
>
>
> The issue arrives when multiple XA transactions are done in parallel and 
> there is either a lock timeout or a lock deadlock detected.  When this 
> happens the connection is leaked in the Glassfish connection pool and the 
> client thread hangs in 
> "org.apache.derby.client.netReply.fill(Reply.java:172)".  
> Shutting down the app server fails because the thread has a lock in 
> "org.apache.derby.client.net.NetConnection40" and another task is calling 
> "org.apache.derby.client.ClientPooledConnection.close(ClientPooledConnection.java:214)"
>  which is waiting for the lock.
> Killing the appsever using "kill" and then attempting to shutdown Derby 
> network server causes the Network Server to hang.  One of the threads hangs 
> waiting for a lock at 
> "org.apache.derby.impl.drda.NeworkServerControlImpl.removeFromSessionTable(NetworkServerControlImpl.java:1525)"
>  and the "main" thread has this locked at 
> "org.apache.derby.impl.drda.NetworkServerControlImpl.executeWork(NetworkServerControlImpl.java:2242)"
>  and it itself is waiting for a lock which belongs to a thread that is stuck 
> at 
> "org.apache.derby.impl.services.locks.ActiveLock.waitForGrant(ActiveLock.java:118)
>  which is in the TIMED_WAITING state.
> Only by killing the Network Server using "kill" is possible at this point.
> There are transactions left even though all clients have been removed.  

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