[jboss-jira] [JBoss JIRA] Commented: (JBAS-4481) Transaction timeouts leave garbage Status.ROLLEDBACK UserTransaction object bound to the thread

[Gavin King (JIRA)]

    [ http://jira.jboss.com/jira/browse/JBAS-4481?page=comments#action_12365540 ] 
            
Gavin King commented on JBAS-4481:
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"however, it will be seeing a transaction in state STATUS_ROLLEDBACK, which it does not know how to deal with. It should really call rollback in this case"

Yes, this is what is missing.


"However, the application code should not be giving it a dirty Thread in the first place."

Irrelevant, because:

(1) It is actually, strictly speaking, *impossible* for a JSF application to clean up transactions properly, since the only place to put a finally block around the whole transaction would be in a servlet filter, and applications are not supposed to do tx management in servlet filters (though all appservers let you do it in practice).

(2)  I guarantee you that if you survey 100 experienced Java EE developers, you will not find a single one who thinks that it is necessary to call rollback() on a transaction that is STATUS_ROLLEDBACK. 

(3) If you survey 100 Java EE applications which do transaction management via UserTransaction, you will find at least 300 bugs in the transaction management code. 

(4) And, frankly, I disagree that this is required of the application anyway. The EE spec (read it, please) very clearly sets up the expectation that the container cleans up transactions at the end of the request.

Regardless of the above, ALL applications have bugs! The container cannot expect the application to be "well-behaved". It has to exhibit robust behavior even when the application behaves badly. It should be utterly impossible for a "bug" in one request to cause the failure of future requests. That escalates a minor bug into a catastrophic failure of the production system.

I'm hammering on this stuff because this is the second time I have seen a problem like this with the tx management code in JBoss AS, and both times people tried to argue that it was the fault of the application, and that no fix was required to JBoss.


> Transaction timeouts leave garbage Status.ROLLEDBACK UserTransaction object bound to the thread
> -----------------------------------------------------------------------------------------------
>
>                 Key: JBAS-4481
>                 URL: http://jira.jboss.com/jira/browse/JBAS-4481
>             Project: JBoss Application Server
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>          Components: Transaction Manager
>    Affects Versions: JBossAS-4.2.0.GA
>            Reporter: Gavin King
>         Assigned To: Gavin King
>            Priority: Blocker
>             Fix For: JBossAS-4.2.1.CR1
>
>         Attachments: test4481.tar
>
>
> If a transaction timeout occurs, the UserTransaction object does not get cleaned up from the thread, even after the request ends and the thread returns to the pool. Future requests will not be able to begin() a transaction, since the STATUS_ROLLEDBACK UserTransaction throws this exception:
> Caused by: javax.transaction.NotSupportedException
> 	at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.begin(BaseTransaction.java:79)
> 	at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.begin(BaseTransactionManagerDelegate.java:77)
> 	at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.begin(ServerVMClientUserTransaction.java:124)
> 	at org.jboss.seam.transaction.UTTransaction.begin(UTTransaction.java:29)
> This means that any transaction timeout that occurs will leave the application server in a permanently broken state and require a server restart. Hence 4.2.0.GA is currently unusable in production!
> This needs to be fixed in an immediate patch release.

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