[jboss-user] [JBoss Messaging] - unable to choose a default cluster node for messaging

bodrin do-not-reply at jboss.com
Wed Jan 9 07:59:39 EST 2008


I want to setup something like a master-slave cluster - all jms clients (external) using only the master node and switch to the slave only if the master is down.

So, first looking at http://docs.jboss.org/jbossas/jboss4guide/r4/html/cluster.chapt.html

  | 16.2.2. Client configuration
  | 
  | The JNDI client needs to be aware of the HA-JNDI cluster. 
  | 
  | ...
  | 
  | java.naming.provier.url=server1:1100,server2:1100,server3:1100,server4:1100
  |             
  | 
  | When initialising, the JNP client code will try to get in touch with each server node from the list, one after the other, stopping as soon as one server has been reached. It will then download the HA-JNDI stub from this node.
  | Note
  | 
  | There is no load balancing behavior in the JNP client lookup process. It just goes through the provider list and use the first available server. The HA-JNDI provider list only needs to contain a subset of HA-JNDI nodes in the cluster.
  | 

I can set it like this:

  | java.naming.provider.url=master:1200,slave:1300
  | 

Then I lookup the "/ClusteredConnectionFactory" which is configured to not support load-balancing via

  | <attribute name="SupportsLoadBalancing">false</attribute> 
  | 
in JBOSS_CONFIG\deploy\jboss-messaging.sar\connection-factories-service.xml

I have observed that subsequent createConnection() calls on the ConnectionFactory object chooses one and the same cluster node.

The problem is that ones it is the master : 


  | ant
  | Buildfile: build.xml
  | 
  | identify:
  |      [echo] ###########################################################################
  |      [echo] #                Running the DISTRIBUTED QUEUE example                    #
  |      [echo] ###########################################################################
  |      [echo] The queue:      testDistributedQueue
  |      [echo] The client jar: ../..//jboss-messaging-client.jar
  | 
  | sanity-check:
  | 
  | init:
  | 
  | compile:
  | 
  | run:
  |      [java] Distributed queue /queue/testDistributedQueue exists
  |      [java] java.lang.RuntimeException: Assertion failed, 0 == 0
  |      [java]     at org.jboss.example.jms.common.ExampleSupport.assertNotEquals(ExampleSupport.java:85)
  |      [java]     at org.jboss.example.jms.distributedqueue.DistributedQueueExample.example(DistributedQueueExample.java:89)
  |      [java]     at org.jboss.example.jms.common.ExampleSupport.run(ExampleSupport.java:147)
  |      [java]     at org.jboss.example.jms.distributedqueue.DistributedQueueExample.main(DistributedQueueExample.java:173)
  |      [java]
  |      [java] #####################
  |      [java] ###    FAILURE!   ###
  |      [java] #####################
  | 
  | BUILD FAILED
  | 

... but sometimes it is the slave :


  | ant
  | Buildfile: build.xml
  | 
  | identify:
  |      [echo] ###########################################################################
  |      [echo] #                Running the DISTRIBUTED QUEUE example                    #
  |      [echo] ###########################################################################
  |      [echo] The queue:      testDistributedQueue
  |      [echo] The client jar: ../..//jboss-messaging-client.jar
  | 
  | sanity-check:
  | 
  | init:
  | 
  | compile:
  | 
  | run:
  |      [java] Distributed queue /queue/testDistributedQueue exists
  |      [java] java.lang.RuntimeException: Assertion failed, 1 == 1
  |      [java]     at org.jboss.example.jms.common.ExampleSupport.assertNotEquals(ExampleSupport.java:85)
  |      [java]     at org.jboss.example.jms.distributedqueue.DistributedQueueExample.example(DistributedQueueExample.java:89)
  |      [java]     at org.jboss.example.jms.common.ExampleSupport.run(ExampleSupport.java:147)
  |      [java]     at org.jboss.example.jms.distributedqueue.DistributedQueueExample.main(DistributedQueueExample.java:173)
  |      [java]
  |      [java] #####################
  |      [java] ###    FAILURE!   ###
  |      [java] #####################
  | 
  | BUILD FAILED
  | 

Do you know if it is possible to make such a setup that it will always choose the master (serviceID=0) node?
I mean the one where the ha-jndi stub is connected to (There is no load balancing behavior in the JNP client lookup process.) ?

Note that I have changed the distributed-queue example - I have added an InitialContext configuration:

  | ...
  |          // connecting to the first node
  | 		java.util.Hashtable properties = new java.util.Hashtable();
  | 		properties.put(javax.naming.Context.INITIAL_CONTEXT_FACTORY,
  | 			"org.jnp.interfaces.NamingContextFactory");
  | 		properties.put(javax.naming.Context.URL_PKG_PREFIXES,
  | 			"org.jboss.naming:org.jnp.interfaces");
  | 		properties.put(javax.naming.Context.PROVIDER_URL, "localhost:1200,localhost:1300");
  | 
  |          ic = new InitialContext(properties);
  | ...
  | 


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