IJ000609: Attempt to return connection twice in EAP 6

Issue

• We've struggle with a problem which shows up as the following exception

IJ000609: Attempt to return connection twice: org.jboss.jca.core.connectionmanager.listener.TxConnectionListener@44405f2e[state=NORMAL managed connection=org.jboss.jca.adapters.jdbc.local.LocalManagedConnection@52c9fe04 connection handles=0 lastUse=1460708280963 trackByTx=false pool=org.jboss.jca.core.connectionmanager.pool.strategy.OnePool@63542a07 pool internal context=SemaphoreArrayListManagedConnectionPool@731fd564[pool=TargenioDS] xaResource=LocalXAResourceImpl@5e28e803[connectionListener=44405f2e connectionManager=2d0680e5 warned=false currentXid=null productName=Microsoft SQL Server productVersion=11.00.6020 jndiName=java:jboss/datasources/testDS] txSync=null]: java.lang.Throwable: STACKTRACE
at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.returnConnection(SemaphoreArrayListManagedConnectionPool.java:554)

• We found link Connectionmanager attempts to return connection twice about this error, It simply says, that this is an application problem. Because we cannot see an implementation error at first sight.

• The below code causing this error is a simple timer bean that manages transactions by itself. Within a loop, transactions are created and finished. Simplified the situation is this.

@Stateless
@TransactionManagement(TransactionManagementType.BEAN)
public class TestBean1 extends TestBean implements Test {

    @Resource
    context context;

    @Timeout
    public void processes(Timer timer) {
    ...

        try {
            method1();
    }
    catch (Exception e) {
        logException(e, null);
        throw new EJBException(e);
    }
    }

 protected void method1()
        throws SQLException, SecurityException, IllegalStateException, RollbackException, HeuristicMixedException,
            HeuristicRollbackException, SystemException, NotSupportedException
    {
         ....
        for (exList a : someLists) {
         try {
        ...
        method2();
        }
    catch (CustomException e) {
 logException(e, null);
    }
    }
  }

    protected void method2()
    throws SQLException,CustomException, SecurityException, IllegalStateException, RollbackException, HeuristicMixedException,
        HeuristicRollbackException, SystemException, NotSupportedException
 {
      UserTransaction transaction = context.getUserTransaction();
      transaction.begin();

          try {
        // call a couple of service methods that participate in the transaction just created.
        ...

            transaction.commit();
          }
          catch (CustomException2 e) {
           // here the error seems to arise:
           transaction.rollback();
          }
          finally {
              // finally block
          }
  }
}