[jboss-jira] [JBoss JIRA] Closed: (JBAS-5040) Locked entities won't be released correctly after transaction timeout

[Adrian Brock (JIRA)]

     [ http://jira.jboss.com/jira/browse/JBAS-5040?page=all ]

Adrian Brock closed JBAS-5040.
------------------------------

    Resolution: Rejected

What you describe is a self deadlock and can never work regardless of transaction timeout.

Locking is by transaction not thread.

ejb1 (lock entity - tx1) -> RequiresNew/UserTransaction -> ejb2 (try to lock entity - tx2) -> deadlock
tx2 cannot lock the entity because tx1 holds the lock. 
tx1 cannot release the lock because it won't complete until tx2 completes.

Please use the forums to ask for help before raising bug reports.

We used to check for self deadlocks but that introduced spurious reports of deadlock
when mulitple clients use remote user tranasctions but share the same pooled
server threads during their requests.

> Locked entities won't be released correctly after transaction timeout
> ---------------------------------------------------------------------
>
>                 Key: JBAS-5040
>                 URL: http://jira.jboss.com/jira/browse/JBAS-5040
>             Project: JBoss Application Server
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>          Components: Transaction Manager
>    Affects Versions: JBossAS-4.2.2.GA
>            Reporter: Christian Michels
>         Assigned To: Adrian Brock
>
> When locking an entity in a (outer) user transaction and trying to lock the same entitity in a inner transaction (with a smaller txTimeout), the entity will not be released, if the inner transaction timed out.
> The entity won't be released until the outer transaction timed out.
> With JBoss 4.0.4, the inner transaction rollback will be resolved after a short while:
> 18:56:14,237 WARN  [TransactionImpl] Transaction TransactionImpl:XidImpl[FormatId=257, GlobalId=PCTR694/17, BranchQual=, localId=17] timed out. status=STATUS_ACTIVE
> 18:56:17,237 ERROR [BeanLock] Thread[RMI TCP Connection(2)-172.22.6.85,5,RMI Runtime]Saw rolled back tx=TransactionImpl:XidImpl[FormatId=257, GlobalId=PCTR694/17, BranchQual=, localId=17] waiting for txLock
> 18:56:17,237 ERROR [LogInterceptor] TransactionRolledbackException in method: public abstract void kam.jbosstest.transactionlocking.LockedEntityEJBRemote.loadIntoTransaction() throws java.rmi.RemoteException, causedBy:
> java.lang.RuntimeException: Transaction marked for rollback, possibly a timeout
> ...
> e.g.
> EntityLockingEJBHome entityLockingHome = (EntityLockingEJBHome) ctx.lookup("EntityLockingEJB");
> kam.jbosstest.transactionlocking.EntityLockingEJBRemote entityLockingRemote = entityLockingHome.create();
> LockedEntityEJBHome lockedEntityHome =
> 				(LockedEntityEJBHome) ctx.lookup("LockedEntityEJB");
> LockedEntityEJBRemote entity = null;
> try {
>         entity = lockedEntityHome.findByPrimaryKey(1);
> } catch (FinderException e) {
>         throw new Exception(e);
> }
> UserTransaction ut = (UserTransaction) ctx.lookup("UserTransaction");
> ut.setTransactionTimeout(10);
> System.out.println("Starting transaction (timeout=10s)...");
> Date start = new Date(System.currentTimeMillis());
> ut.begin();
> System.out.println("Date:" + start);
> System.out.println("...locking entity in client context...");
> entity.loadIntoTransaction();
> try{
> 	System.out.println("...trying to lock the same entity in a new transaction with 2s txTimeout...");
> 	entityLockingRemote.lockResource(1, 2);
> }catch(Exception e){
> 	e.printStackTrace();
> }
> Date end = new Date(System.currentTimeMillis());
> System.out.println("Application was locked for: " + (end.getTime() - start.getTime()) + "ms instead of about 2s");

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