Poblem invoking actions concurrently

[cjunge]

Hi, I have a problem invoking actions from an ESB aware web service.

Since I need to invoke several actions that invoke different web services that need to be located using the UDDI registry, I decided to use threads to do it in a parallel fashion. Each thread locates the service in the registry, invokes it and then returns the result to the ESB aware service via a Courrier.

It works flawlessly when I invoke it only once, but if I invoke the service many times concurrently I get the following exceptions.

org.jboss.soa.esb.actions.ActionProcessingException: Unexpected invocation target exception from processor
at org.jboss.soa.esb.listeners.message.ActionProcessorMethodInfo.processMethods(ActionProcessorMethodInfo.java:123)
at org.jboss.soa.esb.listeners.message.OverriddenActionLifecycleProcessor.process(OverriddenActionLifecycleProcessor.java:74)
at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:206)
at org.jboss.soa.esb.listeners.message.MessageAwareListener$1.run(MessageAwareListener.java:300)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.lang.NullPointerException
at cl.met.StocksAction.GetStocks(StocksAction.java:60)
at sun.reflect.GeneratedMethodAccessor119.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.jboss.soa.esb.listeners.message.ActionProcessorMethodInfo.processMethods(ActionProcessorMethodInfo.java:102)
... 6 more

Where StocksAction.java:60 is:

String codProd = (String) params[0];

I am passing the parameters as an Object array (Object []) as discussed previously in this forum. I am retrieving the parmeters from the message in the following way.

Object [] params = (Object[]) message.getBody().get("params");

Having used the add function in the sender off course:

Message requestMessage = MessageFactory.getInstance().getMessage(MessageType.JBOSS_XML);
requestMessage.getBody().add("params",params);

I also get an error while trying to return the message from the action to the ESB aware web service.

org.jboss.soa.esb.actions.ActionProcessingException: Unexpected invocation target exception from processor
at org.jboss.soa.esb.listeners.message.ActionProcessorMethodInfo.processMethods(ActionProcessorMethodInfo.java:123)
at org.jboss.soa.esb.listeners.message.OverriddenActionLifecycleProcessor.process(OverriddenActionLifecycleProcessor.java:74)
at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:206)
at org.jboss.soa.esb.listeners.message.MessageAwareListener$1.run(MessageAwareListener.java:300)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)
Caused by: org.jboss.soa.esb.couriers.CourierException: No deliver courier
at org.jboss.internal.soa.esb.couriers.TwoWayCourierImpl.deliver(TwoWayCourierImpl.java:157)
at cl.met.PreciosAction.GetPrecios(PreciosAction.java:90)
at sun.reflect.GeneratedMethodAccessor120.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.jboss.soa.esb.listeners.message.ActionProcessorMethodInfo.processMethods(ActionProcessorMethodInfo.java:102)
... 6 more


Where PreciosAction.java:90 is:

EPR replyEPR = message.getHeader().getCall().getReplyTo();
Courier courier = CourierFactory.getCourier(replyEPR);
courier.deliver(responseMessage); // this is line 90
CourierUtil.cleanCourier(courier);

The ESB aware web service sends the message to the action using a TwoWayCourrier and setting a propper replyEPR to the message as explained by the webservice quickstart.

EPR replyEPR = CourierUtil.getTemporaryReplyToEpr(requestEPR);
requestMessage.getHeader().getCall().setReplyTo(replyEPR);

Since this only happens when I make simultaneous calls to the web service I assume there is a problem with my threads, but they don't share pointers to any data so there shouldn't be any data races.

I have one EsbCallThread that receives a category, a service and an Obeject[] and sends the message to the corresponding action adding the array of objects to the message as described earlier in this post.

Any ideas why this could be happening?

Thanks,
Cristian

[kconner]

Hiya Cristian.

"cjunge" wrote:

String codProd = (String) params[0];

If the error is on this line then it would suggest that the value of params is null.

"cjunge" wrote:
Caused by: org.jboss.soa.esb.couriers.CourierException: No deliver courier

This is an old message but it means that the EPR is null, implying that the reply EPR from your message is null.

Can you add a check for null values to see if this is the case?

I would be interested to see if this still happens with the latest code in svn, are you in a position to update?

[cjunge]

Thanks for answering Kurt.

Yes, params and replyEPR are null and that causes the exceptions. I've checked this adding tests in the code. What seems strange to me is that this works fine if I only invoke the web service once. If I had made a mistake in the code shouldn't this happen every time?

Where can I check out the latest svn version?

[kconner]

Wrong K ;-)

You can obtain the latest code from http://anonsvn.labs.jboss.com/labs/jbossesb/trunk

Kev

[marklittle]

Alternatively wait until next week when we'll be releasing MR2. Should be early in the week.

[cjunge]

I tried it on 4.2MR2 and it worked fine. I had to change some code in the esb aware ws and in the actions because the api changed a bit. Now it' easier :). I don't have to deal explicitly with couriers and endpoints. Thank you all.