Using the JMX interface to develop your own monitoring application

You can use AdminClient API to get Performance Monitoring Infrastructure (PMI) data by using either PerfMBean or individual MBeans.

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 ObjectNames.
   After 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(mynode);
   
           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 application server 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(mynode) &
   & server.equals(myserver)) {
   		perfOName = on;
               }
   	}

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

   
   - setStatisticSet: Enable PMI data using the pre-defined statistic sets.
   	Object[] params = new Object[] { com.ibm.websphere.pmi.stat.StatConstants.STATISTIC_SET_EXTENDED};
   	String[] signature = new String[] {"java.lang.String"};
   	ac.invoke (perfOName, "setStatisticSet", params, signature);
   
   - getStatisticSet: Returns the current statistic set.
   	String setname = (String) ac.invoke (perfOName, "getStatisticSet", null, null);
   
   - setCustomSetString: Customizing PMI data that is enabled using fine-grained control. 
   This method allows to enable or disable statistics selectively. The format of the custom 
   set specification string is STATS_NAME=ID1,ID2,ID3 seperated by ':', where STATS_NAME 
   and IDs are defined in WS*Stat interfaces in com.ibm.websphere.pmi.stat package.
   	params[0] = new String (WSJVMStats.NAME + "=" + WSJVMStats.HeapSize);
   	params[1] = new Boolean (false);
   	signature = new String[] {"java.lang.String", "java.lang.Boolean"};
   	ac.invoke (perfOName, "setCustomSetString", params, signature);
   
     Note: Statistics that are not listed in the set string are not changed.
    
   - getCustomSetString: Returns the current custom set specification as a string
   	String setstring = (String) ac.invoke (perfOName, "getCustomSetString", null, null);
   
   
   - setInstrumentationLevel: set the instrumentation level
               params[0] = new MBeanLevelSpec(objectName, new int[]{WSJVMStats.HEAPSIZE});
               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
               params[0] = objectName;
               params[1] = new Boolean(recursive);
               String[] signature= new String[]{ 
   "javax.management.ObjectName", "java.lang.Boolean"};
               MBeanLevelSpec[] mlss = (MBeanLevelSpec[])ac.invoke(perfOName, 
   					"getInstrumentationLevel", params, signature);
   
   - setInstrumentationLevel: set the instrumentation level (deprecated in V6.0)
               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 (deprecated in V6.0)
               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);
   
   Refer the API documentation for deprecated classes
   
   

   • 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.