Hi,

In JBoss EAP5 or AS6 or previous releases there was a concept of Partition Name which could be used to get the list of active cluster members, However in JBoss AS7 there is no concept of PartitionName rather in UDP mode the lustering happens based on the multicast asddress (Clustering can be achieved using TCP mode of communication as well). However many developers want to list the number of active members running as part of a JBoss As7 cluster programatically.

NOTE:

Point-1) . In JBoss AS7 until you deploy an application which requires clustering the JBoss will now start the clustering services. So in case of web Applications you should deploy at least one application on your Cluster members which has <distributable/> tag specified in it’s “WEB-INF/web.xml” file.

Point-2) . If you are using EJBs (and not web application to deploy on your cluster) make sure that the EJBs are clustered in order to start Cluster services. EJBs can be annotated using the following annotation in order to be clustered. @org.jboss.ejb3.annotation.Clustered

Point-3) . In Case of WebBased cluster the ObjectName of the Clustered instance will be “jgroups:type=channel,cluster=web” by default which can be used in the JMX Code in order to look query the MBean.

Point-3) . In Case of EJBBased cluster the ObjectName of the Clustered instance will be “jgroups:type=channel,cluster=ejb” by default which can be used in the JMX Code in order to look query the MBean.

Point-5) . If you are running your Server in Domain Mode then you should not use the Native Management Port 9999 in order to query the MBeans rather you should use the individual server’s Remoting Port 4447 in your JMX Code. by adding the following configuration on your JBoss Profile inside domain.xml you can allow accessing the MBeans via Remoting port 4447 rather than (native management port 9999)

<subsystem xmlns="urn:jboss:domain:jmx:1.1">
    <show-model value="true"/>
     <remoting-connector  use-management-endpoint="false" />
</subsystem>

Point-6) . If you are using Native Management Interface port 9999 in order to query your Cluster MBean (in standalone mode) then you should use the Credentials (username/password) for a user belonging to ManagementRealm, But in Domain mode as we need to connect to server using Remoting Port (4447) so you should create a ApplicationRealm user. in all the cluster Hosts.

Writing the JMX codce to query Cluster MBean

import java.util.Hashtable;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

public class AS7ClusterView {
	public static void main(String[] args) throws Exception {

		String host = "10.10.10.10"; // Your JBoss Native Interface Bin Address default is localhost
		int port = 9999;             // management port     // In Domain Mode you should use  4447 port of individual server
		String urlString = "service:jmx:remoting-jmx://" + host + ":" + port;
		System.out.println(" nnt**** urlString: " + urlString);
                String webClusterObjectName="jgroups:type=channel,cluster="web"";
                //String ejbClusterObjectName="jgroups:type=channel,cluster="ejb"";


		JMXServiceURL serviceURL = new JMXServiceURL(urlString);


		Hashtable h = new Hashtable();
		String[] credentials = new String[] { "admin", "admin123" };
		h.put("jmx.remote.credentials", credentials);

		JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceURL,null);
		MBeanServerConnection connection = jmxConnector.getMBeanServerConnection();
		ObjectName objectName = new ObjectName(webClusterObjectName);
		String clusterView = (String) connection.getAttribute(objectName,"View");
		Long receivedMessages = (Long) connection.getAttribute(objectName,"ReceivedMessages");
		String name = (String) connection.getAttribute(objectName, "Name");
		String clusterName = (String) connection.getAttribute(objectName,"ClusterName");

		System.out.println(" clusterView = " + clusterView);
		System.out.println(" receivedMessages = " + receivedMessages);
		System.out.println(" name = " + name);
		System.out.println(" clusterName = " + clusterName);
		jmxConnector.close();
	}

}

Now open a Terminal where we need to set the PATh and CLASSPATH like following and then compile and run the program:

For UNIX Based Operating System:

export PATH=/home/userone/jdk1.6.0_21/bin:$PATH
export CLASSPATH=/home/userone/jboss-as-7.1.2.Final/bin/client/jboss-client.jar:$CLASSPATH:.:

++++++++++++++++++++++++++++++++
For Windows Based Operating System

set PATH=C:jdk1.6.0_21bin;%PATH%
set CLASSPATH=c:jboss-as-7.1.2.Finalbinclientjboss-client.jar;%CLASSPATH%;.;

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Thanks 🙂
MiddlewareMagic Team

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