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 019package org.apache.hadoop.metrics2.lib; 020 021import java.util.concurrent.atomic.AtomicReference; 022import javax.management.ObjectName; 023 024import org.apache.hadoop.classification.InterfaceAudience; 025import org.apache.hadoop.classification.InterfaceStability; 026import org.apache.hadoop.metrics2.MetricsException; 027import org.apache.hadoop.metrics2.MetricsSystem; 028import org.apache.hadoop.metrics2.impl.MetricsSystemImpl; 029 030/** 031 * The default metrics system singleton 032 */ 033@InterfaceAudience.Public 034@InterfaceStability.Evolving 035public enum DefaultMetricsSystem { 036 INSTANCE; // the singleton 037 038 private AtomicReference<MetricsSystem> impl = 039 new AtomicReference<MetricsSystem>(new MetricsSystemImpl()); 040 volatile boolean miniClusterMode = false; 041 transient final UniqueNames mBeanNames = new UniqueNames(); 042 transient final UniqueNames sourceNames = new UniqueNames(); 043 044 /** 045 * Convenience method to initialize the metrics system 046 * @param prefix for the metrics system configuration 047 * @return the metrics system instance 048 */ 049 public static MetricsSystem initialize(String prefix) { 050 return INSTANCE.init(prefix); 051 } 052 053 MetricsSystem init(String prefix) { 054 return impl.get().init(prefix); 055 } 056 057 /** 058 * @return the metrics system object 059 */ 060 public static MetricsSystem instance() { 061 return INSTANCE.getImpl(); 062 } 063 064 /** 065 * Shutdown the metrics system 066 */ 067 public static void shutdown() { 068 INSTANCE.shutdownInstance(); 069 } 070 071 void shutdownInstance() { 072 boolean last = impl.get().shutdown(); 073 if (last) synchronized(this) { 074 mBeanNames.map.clear(); 075 sourceNames.map.clear(); 076 } 077 } 078 079 @InterfaceAudience.Private 080 public static MetricsSystem setInstance(MetricsSystem ms) { 081 return INSTANCE.setImpl(ms); 082 } 083 084 MetricsSystem setImpl(MetricsSystem ms) { 085 return impl.getAndSet(ms); 086 } 087 088 MetricsSystem getImpl() { return impl.get(); } 089 090 @InterfaceAudience.Private 091 public static void setMiniClusterMode(boolean choice) { 092 INSTANCE.miniClusterMode = choice; 093 } 094 095 @InterfaceAudience.Private 096 public static boolean inMiniClusterMode() { 097 return INSTANCE.miniClusterMode; 098 } 099 100 @InterfaceAudience.Private 101 public static ObjectName newMBeanName(String name) { 102 return INSTANCE.newObjectName(name); 103 } 104 105 @InterfaceAudience.Private 106 public static void removeMBeanName(ObjectName name) { 107 INSTANCE.removeObjectName(name.toString()); 108 } 109 110 @InterfaceAudience.Private 111 public static void removeSourceName(String name) { 112 INSTANCE.removeSource(name); 113 } 114 115 @InterfaceAudience.Private 116 public static String sourceName(String name, boolean dupOK) { 117 return INSTANCE.newSourceName(name, dupOK); 118 } 119 120 synchronized ObjectName newObjectName(String name) { 121 try { 122 if (mBeanNames.map.containsKey(name) && !miniClusterMode) { 123 throw new MetricsException(name +" already exists!"); 124 } 125 return new ObjectName(mBeanNames.uniqueName(name)); 126 } catch (Exception e) { 127 throw new MetricsException(e); 128 } 129 } 130 131 synchronized void removeObjectName(String name) { 132 mBeanNames.map.remove(name); 133 } 134 135 synchronized void removeSource(String name) { 136 sourceNames.map.remove(name); 137 } 138 139 synchronized String newSourceName(String name, boolean dupOK) { 140 if (sourceNames.map.containsKey(name)) { 141 if (dupOK) { 142 return name; 143 } else if (!miniClusterMode) { 144 throw new MetricsException("Metrics source "+ name +" already exists!"); 145 } 146 } 147 return sourceNames.uniqueName(name); 148 } 149}