6 Replies Latest reply on Nov 15, 2002 10:06 PM by garyg

how to delete/create queue because InstanceAlreadyExistsExce

garyg Nov 3, 2002 8:16 PM

If my client for some reason goes down and I have to restart it, I'd get the following exception ...

---

MBeanException: Exception in MBean operation 'createQueue(,java.lang.String,java.lang.String)'
Cause: javax.management.InstanceAlreadyExistsException: jboss.mq.destination:service=Queue,name=trinity already
registered. at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBeanDispatcher.java:303)

---

The following code is used to created this queue ...

---

MBeanServer server = (MBeanServer)MBeanServerFactory.findMBeanServer(null).iterator().next();

server.invoke(new ObjectName("JBossMQ", "service", "Server"), "createQueue", new Object[] { bInfo.getNodeName() }, new String[] {"java.lang.String"});

---

So my question is, if this queue already exists, how would I *unregister* it and then recreate it?

Any help much appreciated.

1. Re: how to delete/create queue because InstanceAlreadyExists

adrian.brock Nov 3, 2002 8:52 PM (in response to garyg)

destroyQueue

Regards,
Adrian
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2. Re: how to delete/create queue because InstanceAlreadyExists

garyg Nov 10, 2002 3:03 AM (in response to garyg)

I was hoping I'd be able to catch an InstanceAlreadyExistsException where I'd then call destroyQueue, but since I'm using the http adaptor to createQueue from a client, I can't catch this exception.

Is there anyway to check to see if the queue exists first?
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3. Re: how to delete/create queue because InstanceAlreadyExists

adrian.brock Nov 10, 2002 9:26 AM (in response to garyg)

import javax.management.*;

ObjectName name = new ObjectName(<queue-mbean-here>);

// Get the MBeanServer
MBeanServer server = MBeanServerFactory.findMBeanServer(null).iterator().next();

// Is the queue registered
boolean registered = server.isRegistered(name);

You can also use server.invoke(...) to create and
destroy the queues.

If you are not local to the VM, you can use the
RMI or EJB adaptor.

Regards,
Adrian
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4. Re: how to delete/create queue because InstanceAlreadyExists

garyg Nov 10, 2002 5:43 PM (in response to garyg)

So I'm using the RMIAdaptor since I'm not local to the VM. But I'm getting the following exceptions ...

javax.naming.CommunicationException: Peek timed out. Root exception is java.io.InterruptedIOException: Peek timed out
at java.net.PlainDatagramSocketImpl.peek(Native Method)
at java.net.DatagramSocket.receive(DatagramSocket.java:349)
at org.jnp.interfaces.NamingContext.discoverServer(NamingContext.java:930)
at org.jnp.interfaces.NamingContext.checkRef(NamingContext.java:1017)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:447)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:440)
at javax.naming.InitialContext.lookup(InitialContext.java:345)

And here's my clients code ...
---

String adaptorName = "jmx:" + props.getProperty("manager.name")
+ ":rmi";

try {
InitialContext ctx = new InitialContext();

RMIAdaptor adaptor = (RMIAdaptor) ctx.lookup(adaptorName);

ObjectName name = new ObjectName("jboss.system:service=MainDeployer");

RemoteMBeanServer server = new RMIConnectorImpl(adaptor);

boolean registered = server.isRegistered(name);

if (registered) {
server.invoke(name, "destroyQueue", new Object[] { server },
new String[] {});
}

server.invoke(name, "createQueue", new Object[] { server },
new String[] {});

Any help much appreciated.
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5. Re: how to delete/create queue because InstanceAlreadyExists

adrian.brock Nov 10, 2002 10:58 PM (in response to garyg)

You have a problem with your jndi.properties?

When you've fixed that your object names are wrong.

The isRegistered() should use the Queue's object name.

The create/destroy queue should be against the
DestinationManager.

Regards,
Adrian
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6. Re: how to delete/create queue because InstanceAlreadyExists

garyg Nov 15, 2002 10:06 PM (in response to garyg)

Still getting the exceptions which I've pasted at the end. I've also included the jndi.properties which I don't see anything wrong with.

java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.provider.url=jnp://192.168.0.10:1099/
java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces
#jnp.socketFactory=org.jnp.interfaces.TimedSocketFactory
#jnp.timeout=0
#jnp.sotimeout=0

--- And here is the new code fixes ...

try {
InitialContext ctx = new InitialContext();

RMIAdaptor adaptor = (RMIAdaptor) ctx.lookup(adaptorName);

ObjectName name = new
ObjectName("jboss.mq:service=DestinationManager");

RemoteMBeanServer server = new RMIConnectorImpl(adaptor);

ObjectName queName = new ObjectName("queue/" +
props.getProperty("fielder.hostname"));

boolean registered = server.isRegistered(queName);

String[] sig = {"java.lang.String"};
Object[] arg = {props.getProperty("fielder.hostname")};

if (registered) {
log.info(Fielder.class, "already registered, destroying queue");
server.invoke(name, "destroyQueue", arg, sig);
}

log.info(Fielder.class, "creating queue");
server.invoke(name, "createQueue", arg, sig);

--- jboss output ---
javax.naming.CommunicationException: Peek timed out. Root exception is java.io.InterruptedIOException: Peek timed out
at java.net.PlainDatagramSocketImpl.peek(Native Method)
at java.net.DatagramSocket.receive(DatagramSocket.java:349)
at org.jnp.interfaces.NamingContext.discoverServer(NamingContext.java:930)
at org.jnp.interfaces.NamingContext.checkRef(NamingContext.java:1017)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:447)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:440)
at javax.naming.InitialContext.lookup(InitialContext.java:345)
at com.neuroquest.cais.clients.fielder.Fielder.createPTP(Unknown Source)
at com.neuroquest.cais.clients.fielder.Fielder.main(Unknown Source)

Any help much appreciated.
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