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https://issues.apache.org/jira/browse/UIMA-2401?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jerry Cwiklik closed UIMA-2401.
-------------------------------
Resolution: Fixed
Fix Version/s: 2.4.0AS
Assignee: Jerry Cwiklik
Replicated the problem with supplied test case. Modified
BaseUIMAAsynchronousEngine_impl to synchronize access to SharedConnection
object during initialization and shutdown of the uima-as client to prevent
concurrent access by multiple threads. After the change, the test case
completes with no exceptions.
> 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
> Assignee: Jerry Cwiklik
> Labels: ibm
> Fix For: 2.4.0AS
>
> Attachments: IllegalStateTimingDefect.zip
>
>
> 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.
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