How to find if the EJB Proxy object is stale and no longer bound to actual bean in the server

[mannu_cse]

We have a cluster of jboss nodes and a service is deployed in these nodes, this service contains a stateless bean which is clustered

There is a client which makes a JNDI lookup and invoked the EJB method.

we make the JNDI lookup at the begining and then invoke the method in future a number of times.

in one case the target service is undeployed from one of the node, which results in

java.lang.IllegalStateException: EJBCLIENT000025: No EJB receiver available for handling [appName:ServerTestService-1.0.1, moduleName:ServerTestEJB-1.0.1, distinctName:] combination for invocation context

What we want is in case the EJB Proxy object is stale ( i.e. bound connection is closed due to service undeployed) we want the proxy object to make a fresh JNDI lookup and bind to another available EJB in the cluster.

Is there any way to find if the object is stale

InitialContext context = null;

         try {

             context = new InitialContext(properties);

             Object ejbObject = context.lookup(jndiName); // here lookup succeeds

             ((ServiceIf) ejbObject ).call(); // making some ejb method call which succeeds

             // wait for some time and service bound to ejbObject might be removed, now make another method call

             if( ejbObject still bound .... dont know how to find this )

             {

                  ((ServiceIf) ejbObject ).anotherCall();

             }

              else

             {

                    // make a fresh JNDI lookup from the cluster

                    ejbObject = context.lookup(jndiName);

                    ((ServiceIf) ejbObject ).anotherCall();

             }

         } catch (final Exception exc) {

             LOG.error("Exception while looking up/executing bean with JNDI {}. Details: {}", jndiName, exc.getMessage());

             throw exc;

         }

[wdfink]

How the properties which are given to create the initialContext look like?

How the lookup jndiName look like?

It is not an guarantee that the proxy target is available if the lookup succeeds.

[mannu_cse]

Since it's a Server to Server EJB call, we are following all the steps to create remote outbound connections in standalone-full-ha.xml

and packaging jboss-ejb-client.xml in client EAR.

As I explain in the sample code, first EJB method call succeeds so the proxy target is available initially.

however during the execution the target could be undeployed, but there are same EJB deployed in other nodes in the cluster

so we want to recover this and make a new JNDI lookup to other available proxy target

Although we thought it should have happened automatically without need of explicitly doing a lookup again.

Also since it's a stateless EJB, if I invoke multiple methods (hundred of times) will all be invoked on same target proxy or

it will be load balanced in the cluster?

And if it's not load balanced, will the server use the SLSB pool to allocate actual ejb object eventually

resulting in different beans used for different method invocation though from the same server's SLSB pool?

[wdfink]

First, if you want to have cluster features yoou need to do a bit.

See my ejb-multi-server quickstart jboss-ejb-client.xml.

If you need initial two server for failover you need to have 2 remote outbound configurations!

If you add such config you will have cluster loadbalancing and failover

As it is a SLSB the target might not the same, there is a pool (server local) which hold beans if you invoke in parallel and need more instances.

Also I've raised a JIRA to simplify the administration in case of a cluster.

[mannu_cse]

Thanks for the help, yes, I see the fail-over, load balacing happening correctly after adding jboss-ejb-client.xml in WEB-INF folder, this got missed out as we were trying to lookup EJB from Web module for the first time.