uima-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gino Bustelo (JIRA)" <...@uima.apache.org>
Subject [jira] [Created] (UIMA-2401) BaseUIMAAsynchronousEngine_impl does not protect access to SharedConnection in a multi-instance, multi-threaded scenario. Possible javax.jms.IllegalStateException.
Date Wed, 09 May 2012 18:37:50 GMT
Gino Bustelo created UIMA-2401:
----------------------------------

             Summary: BaseUIMAAsynchronousEngine_impl does not protect access to SharedConnection
in a multi-instance, multi-threaded scenario. Possible javax.jms.IllegalStateException.
                 Key: UIMA-2401
                 URL: https://issues.apache.org/jira/browse/UIMA-2401
             Project: UIMA
          Issue Type: Bug
          Components: Async Scaleout
    Affects Versions: 2.3.1AS
         Environment: RedHat Enterprise Linux 6.0, Mac OSX Lion 10.7.3
            Reporter: Gino Bustelo


We see this problem sporadically when running one instance of BaseUIMAAsynchronousEngine_impl
per Thread. This means that each request Thread will instantiate its own instance of BaseUIMAAsynchronousEngine_impl
to submit a CAS async. We have noticed in our logs the following exception:

org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngine_impl WARN  2012-05-04 00:10:46,710
[BaseUIMAAsynchronousEngine_impl.803] - Top Level Controller Initialization Exception.
javax.jms.IllegalStateException: The Session is closed
	at org.apache.activemq.ActiveMQSession.checkClosed(ActiveMQSession.java:722)
	at org.apache.activemq.ActiveMQSession.createConsumer(ActiveMQSession.java:1101)
	at org.apache.activemq.ActiveMQSession.createConsumer(ActiveMQSession.java:1060)
	at org.apache.activemq.ActiveMQSession.createConsumer(ActiveMQSession.java:973)
	at org.apache.activemq.ActiveMQSession.createConsumer(ActiveMQSession.java:946)
	at org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngine_impl.initializeConsumer(BaseUIMAAsynchronousEngine_impl.java:523)
	at org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngine_impl.initialize(BaseUIMAAsynchronousEngine_impl.java:687)

Under further inspection, it seems that the BaseUIMAAsynchronousEngine_impl.initialize does
not properly protects the access to the SharedConnection object. Given the following scenario:

Thread 1 is in the middle of a call to UimaAsynchronousEngine.initialize.
Thread 2 is finishing up and calling UimaAsynchronousEngine.stop.

Thread 1 can be schedule out just before trying to create a Consumer (BaseUIMAAsynchronousEngine_impl.java:523).
Thread 2 will call stop() and due to client count, cause the Connection to get closed. When
Thread 1 comes back, the Connection and Session instances that it has reference to are now
invalid.

I've attached a test case that forces the exception to prove that there is no proper mutex
around access to the SharedConnection between initialize and stop. I believe that the code
in question is in BaseUIMAAsynchronousEngine_impl.initialize between lines 682 and 700.

createSharedConnection(brokerURI);
synchronized (connectionMux) {
        // Reuse existing JMS connection if available
        if (sharedConnection != null) {
          initializeProducer(brokerURI, endpoint, sharedConnection.getConnection());
          initializeConsumer(brokerURI, sharedConnection.getConnection());
        } else {
          initializeProducer(brokerURI, endpoint);
          initializeConsumer(brokerURI);
        }

        // Increment number of client instances. SharedConnection object is a static
        // and is used to share a single JMS connection. The connection is closed
        // when the last client finishes processing and calls stop().
        if (sharedConnection != null) {
          sharedConnection.registerClient(this);
        }

}

That entire block should be protected with the sharedConnectionSemaphore.


--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message