How to Access MBeanServerConnection from remote JMX Client in JBoss EAP 6.x

Solution Verified - Updated 6 Aug 2024

Environment

Red Hat JBoss Enterprise Application Platform (EAP)
- 6.x

Issue

The JMX access seems to have changed in JBoss EAP 6, So how can we access the javax.management.MBeanServerConnection in order to query JBoss EAP6.
Is there some function that can be called while JBoss EAP shutdown?
How is JMX-remoting configured in JBoss EAP 6.1?
How can we make visible any MBean registered at the JBoss EAP 6.2 and how to setup JBoss for accessing the JBoss MBeans remotely?
We have several custom mbeans that we are registering at JVM startup using basic JMX APIs. Here is sample code on how we registered:

MBeanServer server = ManagementFactory.getPlatformMBeanServer();
String objectName = packageName + ":type=" + className;
ObjectName mbeanName = new ObjectName(objectName);
server.registerMBean(mbean, mbeanName);

From within the JVM, I can connect to the Platform MBean Server and get information about my custom MBeans but if I try to use the remoting API from a different server I can only see the JBoss MBeans. Remoting code example:

Map feature=new HashMap();
String[] data=new String[]{"id","pwd"};   
feature.put(JMXConnector.CREDENTIALS, data);
String url = "service:jmx:remoting-jmx://{host}:{port}";
JMXServiceURL jurl = new JMXServiceURL(url);
JMXConnector connector = JMXConnectorFactory.connect(jurl, feature);

I am assuming that I am connecting to the domain controller MBean Server and my custom MBeans are registered in the JVM MBean Server. So Is it even possible to connect to custom standard mbeans in domain mode?

Resolution

Note Make sure remoting-jmx classes are in your classpath via jboss-client.jar for a standalone application or for an application running in JBoss EAP 6.x it should have a dependency on org.jboss.remoting-jmx as described in: protocol remoting-jmx

Note: If you are not using JBoss EAP 6 but actually using JBoss EAP 7, see another knowledge article How to access MBeanServerConnection from remote JMX Client in JBoss EAP 7 for details.

The following kind of JMX Code can be used in order to access the JBoss EAP 6 MBeans :

import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
 
public class JMXExample { 
    public static void main(String[] args) throws Exception {
        String host = "localhost";
        int port = 9999;  // management-native port
        String urlString ="service:jmx:remoting-jmx://" + host + ":" + port;
        System.out.println("\n\n\t****  urlString: "+urlString);;
        JMXServiceURL serviceURL = new JMXServiceURL(urlString);
        JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceURL, null);
        MBeanServerConnection connection = jmxConnector.getMBeanServerConnection();
 
        //Invoke on the JBoss AS MBean server
        int count = connection.getMBeanCount();
        System.out.println(count);
        jmxConnector.close();
    }
}

The above code only work with JBoss running locally, If JBoss run remotely, the authentication credentials should be added. Note that the user and password are created via add-user.sh with Management Realm in standalone mode and Application Realm in domain mode (In Windows, use add-user.bat instead). In this condition, the code snippets like:

import java.util.HashMap;
import java.util.Map;
import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
 
public class JMXExample { 
    public static void main(String[] args) throws Exception {
        String host = "remote-host";
        int port = 9999;  // management-native port
        String urlString ="service:jmx:remoting-jmx://" + host + ":" + port;
        System.out.println("\n\n\t****  urlString: "+urlString);;
        JMXServiceURL serviceURL = new JMXServiceURL(urlString);

        Map map = new HashMap();
        String[] credentials = new String[] { "user", "password" };
        map.put("jmx.remote.credentials", credentials);
        JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceURL, map);

        MBeanServerConnection connection = jmxConnector.getMBeanServerConnection();
 
        //Invoke on the JBoss AS MBean server
        int count = connection.getMBeanCount();
        System.out.println(count);
        jmxConnector.close();
    }
}

To compile and run the above sample program, make sure that JAR $JBOSS_HOME/bin/client/jboss-client.jar exists on the JMX client's CLASSPATH.
In domain mode, user need to connect to the individual JBoss instances using the Remoting Port (which defaults to 4447) in order to get the MBean details available on the individual JBoss instances using following url:
```
service:jmx:remoting-jmx://ip:4447 
```
If user want to connect to the JMX MBeanServer using Remoting then use remoting connector under jmx subsystem, do the following chages in the domain.xml.

NOTE: if your server is using ha profile then make changes in ha profile and same for the other servers.
```
<subsystem xmlns="urn:jboss:domain:jmx:1.1">
      <remoting-connector use-management-endpoint="false"/>
</subsystem>
```
Here, by default the property use-management-endpoint=true is true. If the value of use-management-endpoint is true then this connector will use the management endpoint.
By adding the the property use-management-endpoint=false in on respective JBoss Profile inside domain.xml, user can access the MBeans via Remoting port 4447 rather than (native management port 9999).

This knowledge article is for remote JMX Client. If you want to connect to JBoss EAP instance itself from a deployed application on the JBoss EAP instance, you can simply obtains javax.management.MBeanServer from ManagementFactory.getPlatformMBeanServer() without using the above API. See also this knowledge article.

Diagnostic Steps

It's possible to encounter the following error when trying to connect to the remote host:

3:52:17 PM org.xnio.Xnio <clinit>
INFO: XNIO Version 3.0.4.GA-redhat-1
3:52:17 PM org.xnio.nio.NioXnio <clinit>
INFO: XNIO NIO Implementation Version 3.0.4.GA-redhat-1
3:52:17 PM org.jboss.remoting3.EndpointImpl <clinit>
INFO: JBoss Remoting version 3.2.8.GA-redhat-1
Exception in thread "main" java.lang.RuntimeException: Operation failed with status WAITING
	at org.jboss.remotingjmx.RemotingConnector.internalConnect(RemotingConnector.java:168)
	at org.jboss.remotingjmx.RemotingConnector.connect(RemotingConnector.java:94)
	at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:248)
	at org.jboss.example.jmx.client.JMXClient.main(JMXClient.java:31)

This error can be corrected by insuring that the client has proper name (DNS) resolution for the remote host. Otherwise, the client will timeout and disconnect with this stacktrace after 5 seconds. You may also see a corresponding log entry in the JBoss server.log file, on the remote host, that is similar to this:
```
15:52:22,968 ERROR [org.jboss.remoting.remote.connection] (Remoting "remote-host:MANAGEMENT" read-1) JBREM000200: Remote connection failed: java.io.IOException: Connection reset by peer
```

SBR

JBoss Base AS

Product(s)

Red Hat JBoss Enterprise Application Platform

Components

jbossas

Category

Configure

Tags

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