001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.hadoop.metrics2.util;
019
020 import java.lang.management.ManagementFactory;
021 import javax.management.MBeanServer;
022 import javax.management.ObjectName;
023
024 import org.apache.commons.logging.Log;
025 import org.apache.commons.logging.LogFactory;
026 import org.apache.hadoop.classification.InterfaceAudience;
027 import org.apache.hadoop.classification.InterfaceStability;
028 import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
029
030 /**
031 * This util class provides a method to register an MBean using
032 * our standard naming convention as described in the doc
033 * for {link {@link #register(String, String, Object)}
034 */
035 @InterfaceAudience.Public
036 @InterfaceStability.Stable
037 public class MBeans {
038 private static final Log LOG = LogFactory.getLog(MBeans.class);
039
040 /**
041 * Register the MBean using our standard MBeanName format
042 * "hadoop:service=<serviceName>,name=<nameName>"
043 * Where the <serviceName> and <nameName> are the supplied parameters
044 *
045 * @param serviceName
046 * @param nameName
047 * @param theMbean - the MBean to register
048 * @return the named used to register the MBean
049 */
050 static public ObjectName register(String serviceName, String nameName,
051 Object theMbean) {
052 final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
053 ObjectName name = getMBeanName(serviceName, nameName);
054 try {
055 mbs.registerMBean(theMbean, name);
056 LOG.debug("Registered "+ name);
057 return name;
058 } catch (Exception e) {
059 LOG.warn("Error registering "+ name, e);
060 }
061 return null;
062 }
063
064 static public void unregister(ObjectName mbeanName) {
065 LOG.debug("Unregistering "+ mbeanName);
066 final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
067 if (mbeanName == null) {
068 LOG.debug("Stacktrace: ", new Throwable());
069 return;
070 }
071 try {
072 mbs.unregisterMBean(mbeanName);
073 } catch (Exception e) {
074 LOG.warn("Error unregistering "+ mbeanName, e);
075 }
076 }
077
078 static private ObjectName getMBeanName(String serviceName, String nameName) {
079 ObjectName name = null;
080 String nameStr = "Hadoop:service="+ serviceName +",name="+ nameName;
081 try {
082 name = DefaultMetricsSystem.newMBeanName(nameStr);
083 } catch (Exception e) {
084 LOG.warn("Error creating MBean object name: "+ nameStr, e);
085 }
086 return name;
087 }
088 }