Re: [Springframework-developer] Spring 1.2 Spring JTA tx timeout, tx rolls back, but no exception th

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Good point - thanks for reporting this! JTA implementations seem to mark
transaction as rollback-only when they have timed out, without further
indication. So unless you attempt an actual resource operation after the
timeout, there is no guarantee than an exception gets thrown before commit.

If Spring discovers a rollback-only status, it assumes that the application
has set the transaction to rollback-only and triggers a silent rollback.
This will usually happen when TransactionStatus.setRollbackOnly() has been
called, instead of configuring a rollback rule, with an application-level
exception getting thrown.

In the case of a JTA timeout, the rollback-only marker comes from the JTA
subsystem, though. Spring effectively misinterprets that marker as driven by
the application, which leads to an inappropriate silent reaction. I'll fix
that for Spring 1.2.1, although it's unfortunately not that trivial for the
general case.

Juergen

-----Original Message-----
From: spr...@li...
[mailto:spr...@li...]On Behalf
Of Dave Ballard
Sent: Friday, May 20, 2005 10:44 PM
To: spr...@li...
Subject: [Springframework-developer] Spring 1.2 Spring JTA tx timeout,
tx rolls back, but no exception thrown (another race condition)

Hi Juergen,

Using unpatched Spring 1.2 on WebLogic 6.1. I've defined a
Spring-managed service bean, with the following transaction manager and
transaction interceptor beans:

  <bean id="MyTransactionManager"
class="org.springframework.transaction.jta.JtaTransactionManager">
    <property
name="transactionManagerName"><value>java:comp/UserTransaction</value></prop
erty>
  </bean>

  <bean id="MyTransactionInterceptor"
class="org.springframework.transaction.interceptor.TransactionInterceptor">
    <property name="transactionManager"><ref
bean="MyTransactionManager"/></property>
    <property name="transactionAttributeSource">
      <value>
        PaymentService.commit=PROPAGATION_REQUIRED,-Exception
      </value>
    </property>
  </bean>

The transactional demarcation causes a commit when the method succeeds,
and causes a rollback when an exception is thrown (and throws the
exception), as expected. However, if I introduce a 40 second sleep in
the method, the transaction rolls back as expected, but sometimes no
exception is thrown. In the case where no exception is thrown, I can see
in the Spring log:

 WARN 14:45:03,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (EjbUtils.java:626) - START SLEEP 40:
PaymentServiceImpl.commit() 40 seconds......
 WARN 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (EjbUtils.java:633) - DONE  SLEEP 40:
PaymentServiceImpl.commit() 40 seconds......
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (TransactionAspectSupport.java:258) - Invoking commit for
transaction on PaymentService.commit
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (AbstractPlatformTransactionManager.java:382) -
Transactional code has requested rollback
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (AbstractPlatformTransactionManager.java:542) - Triggering
beforeCompletion synchronization
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (TransactionSynchronizationManager.java:177) - Removed
value [org.springframework.orm.hibernate.SessionHolder@57f820] for key
[net.sf.hibernate.impl.SessionFactoryImpl@39569e] from thread
[ExecuteThread: '30' for queue: 'default']
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (SessionFactoryUtils.java:730) - Closing Hibernate Session
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (AbstractPlatformTransactionManager.java:463) - Initiating
transaction rollback
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (JtaTransactionManager.java:719) - Rolling back JTA transaction
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (AbstractPlatformTransactionManager.java:572) - Triggering
afterCompletion synchronization
DEBUG 14:45:43,156 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (TransactionSynchronizationManager.java:252) - Clearing
transaction synchronization
 INFO 14:45:43,171 [ExecuteThread: '30' for queue: 'default']
[edemo_acme] (PaymentCommit.java:167) - PERFORMANCE END   PaymentCommit

This is an intermittent problem that occurs in both 1.1.5 and 1.2. I run
the same test over and over, and while it always rolls back, it only
sometimes throws an exception. In the case where it does throw an
exception, the log is different:

 WARN 15:18:54,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (EjbUtils.java:626) - START SLEEP 40:
PaymentServiceImpl.commit() 40 seconds......
 WARN 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (EjbUtils.java:633) - DONE  SLEEP 40:
PaymentServiceImpl.commit() 40 seconds......
DEBUG 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (TransactionAspectSupport.java:241) - Invoking commit for
transaction on method 'commit' in class [PaymentService]
DEBUG 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (AbstractPlatformTransactionManager.java:523) - Triggering
beforeCommit synchronization
DEBUG 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (SessionFactoryUtils.java:809) - Flushing Hibernate session
on transaction synchronization
DEBUG 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (SQLErrorCodeSQLExceptionTranslator.java:225) - Unable to
translate SQLException with errorCode '0', will now try the fallback
translator
DEBUG 15:19:34,109 [ExecuteThread: '31' for queue: 'default']
[edemo_acme] (SQLStateSQLExceptionTranslator.java:74) - Translating
SQLException with SQLState 'null' and errorCode '0' and message [The
transaction is no longer active (status = Rolled back.
[Reason=weblogic.transaction.internal.TimedOutException: Transaction
timed out after 28 seconds
[snip]

This appears to be another race condition. In the case where the
exception is thrown, the transaction has not yet been flagged as
rollback-only. The code proceeds to attempt a hibernate flush(), and
this causes a SQLException(TimedOutException) to be thrown.

In the first case where no exception is thrown, the transaction has
already been flagged rollback-only, so the code never calls hibernate
flush, and simply returns w/o an exception after rolling back the tx.

This is a pretty serious problem for my application because the calling
code has no idea that the transaction rolled back.

Thanks,
Dave

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Re: [Springframework-developer] Spring 1.2 Spring JTA tx timeout, tx rolls back, but no exception th

Re: [Springframework-developer] Spring 1.2 Spring JTA tx timeout, tx rolls back, but no exception thrown (another race condition)