Develop your own monitoring application with the Java Management Extension interface

WAS allows you to invoke methods on MBeans through the AdminClient Java Management Extension (JMX) interface. You can use AdminClient API to get PMI data by using either PerfMBean or individual MBeans. See information about using individual MBeans at bottom of this article.

Individual MBeans provide the Stats attribute from which you can get PMI data. The PerfMBean provides extended methods for PMI administration and more efficient ways to access PMI data. To set the PMI module instrumentation level, invoke methods on PerfMBean. To query PMI data from multiple MBeans, it is faster to invoke the getStatsArray method in PerfMBean than to get the Stats attribute from multiple individual MBeans. PMI can be delivered in a single JMX cell through PerfMBean, but multiple JMX calls have to be made through individual MBeans.

See the topic "Developing an administrative client program" for more information on AdminClient JMX. After the performance monitoring service is enabled and the application server is started or cycled, a PerfMBean is located in each application server giving access to PMI data. To use PerfMBean...

  1. Create an instance of AdminClient.When using AdminClient API, you need to first create an instance of AdminClient by passing the host name, port number and connector type.

    The example code is 

            AdminClient ac = null;
        java.util.Properties props = new java.util.Properties();
        props.put(AdminClient.CONNECTOR_TYPE, connector);
        props.put(AdminClient.CONNECTOR_HOST, host);
        props.put(AdminClient.CONNECTOR_PORT, port);
        try {
            ac = AdminClientFactory.createAdminClient(props);
        }
        catch Exception(ex) {
            failed = true;
            new AdminException(ex).printStackTrace();
            System.out.println("getAdminClient: exception");
        }

  2. Use AdminClient to query the MBean ObjectNamesOnce you get the AdminClient instance, you can call queryNames to get a list of MBean ObjectNames depending on your query string. To get all the ObjectNames, you can use the following example code. If you have a specified query string, you will get a subset of ObjectNames 

            javax.management.ObjectName on = new javax.management.ObjectName("WebSphere:*");
        Set objectNameSet= ac.queryNames(on, null);
    // you can check properties like type, name, and process to find a specified ObjectName
    After you get all the ObjectNames, you can use the following example code to get all the node names 

            HashSet nodeSet = new HashSet();
           for Iterator(i = objectNameSet.iterator(); i.hasNext(); on = 
(ObjectName)i.next()) {
            String type = on.getKeyProperty("type");
            if(type != null && type.equals("Server")) {
        nodeSet.add(servers[i].getKeyProperty("node"));
            }
    }
    Note, this will only return nodes that are started.To list running servers on the node, you can either check the node name and type for all the ObjectNames or use the following example code 

         StringBuffer oNameQuery= new StringBuffer(41);
        oNameQuery.append("WebSphere:*");
        oNameQuery.append(",type=").append("Server");
        oNameQuery.append(",node=").append(node);

        oSet= ac.queryNames(new ObjectName(oNameQuery.toString()), null);
           Iterator i = objectNameSet.iterator ();
                while (i.hasNext ()) {
                on=(objectName) i.next();
            String process= on[i].getKeyProperty("process");
            serversArrayList.add(process);
        }

  3. Get the PerfMBean ObjectName for the appserver from which you want to get PMI data.Use this example code 

            for Iterator(i = objectNameSet.iterator(); i.hasNext(); on = (ObjectName)i.next()) {
        // First make sure the node name and server name is what you want
        // Second, check if the type is Perf
            String type = on.getKeyProperty("type");
        String node = on.getKeyProperty("node");
        String process= on.getKeyProperty("process");
            if (type.equals("Perf") && node.equals(node) &
& server.equals(myserver)) {
        perfOName = on;
            }
    }

  4. Invoke operations on PerfMBean through the AdminClient.Once you get the PerfMBean(s) in the appserver from which you want to get PMI data, you can invoke the following operations on the PerfMBean through AdminClient API 

    - setInstrumentationLevel: set the instrmentation level 
            params[0] = new MBeanLevelSpec(objectName, optionalSD, level);
            params[1] = new Boolean(true);
            signature= new String[]{ "com.ibm.websphere.pmi.stat.MBeanLevelSpec", 
"java.lang.Boolean"};
            ac.invoke(perfOName, "setInstrumentationLevel", params, signature);

- getInstrumentationLevel: get the instrumentation level
            Object[] params = new Object[2];
            params[0] = new MBeanStatDescriptor(objectName, optionalSD);
            params[1] = new Boolean(recursive);
            String[] signature= new String[]{ 
"com.ibm.websphere.pmi.stat.MBeanStatDescriptor", "java.lang.Boolean"};
            MBeanLevelSpec[] mlss = (MBeanLevelSpec[])ac.invoke(perfOName, 
"getInstrumentationLevel", params, signature);

- getConfigs: get PMI static config info for all the MBeans
            configs = (PmiModuleConfig[])ac.invoke(perfOName, "getConfigs", null, null);

- getConfig: get PMI static config info for a specific MBean
        ObjectName[] params = {objectName};
        String[] signature= { "javax.management.ObjectName" };
            config = (PmiModuleConfig)ac.invoke(perfOName, "getConfig", params, 
signature);

- getStatsObject: you can use either ObjectName or MBeanStatDescriptor 
            Object[] params    = new Object[2];
            params[0] = objectName;  // either ObjectName or or MBeanStatDescriptor
            params[1] = new Boolean(recursive);
            String[] signature = new String[] { "javax.management.ObjectName", 
"java.lang.Boolean"};
            Stats stats  = (Stats)ac.invoke(perfOName, "getStatsObject", params, 
signature);

  Note: The returned data only have dynamic information (value and time stamp). 
See PmiJmxTest.java for additional code to link the configuration information with the 
returned data.

- getStatsArray: you can use either ObjectName or MBeanStatDescriptor     
            ObjectName[] onames = new ObjectName[]{objectName1, objectName2};
            Object[] params = new Object[]{onames, new Boolean(true)};
            String[] signature = new String[]{"[Ljavax.management.ObjectName;", 
"java.lang.Boolean"};
            Stats[] statsArray = (Stats[])ac.invoke(perfOName, "getStatsArray", 
params, signature);

  Note: The returned data only have dynamic information (value and time stamp). 
See PmiJmxTest.java for additional code to link the configuration information with the 
returned data.

- listStatMembers: navigate the PMI module trees 

            Object[] params = new Object[]{mName};
            String[] signature= new String[]{"javax.management.ObjectName"};
            MBeanStatDescriptor[] msds = (MBeanStatDescriptor[])ac.invoke(perfOName, 
"listStatMembers", params, signature);

or,

            Object[] params = new Object[]{mbeanSD};
            String[] signature= new String[]
{"com.ibm.websphere.pmi.stat.MBeanStatDescriptor"};
            MBeanStatDescriptor[] msds = (MBeanStatDescriptor[])ac.invoke
(perfOName, "listStatMembers", params, signature);

    • To use an individual MBean: You need to get the AdminClient instance and the ObjectName for the individual MBean. Then you can simply get the Stats attribute on the MBean.

 

See Also

Developing an administrative client program
Example: Administering Java Management Extension-based interface