| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.metrics2.lib; |
| |
| import java.lang.ref.WeakReference; |
| import java.lang.reflect.Method; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentLinkedDeque; |
| import java.util.concurrent.ConcurrentMap; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.metrics2.MetricsRecordBuilder; |
| import org.apache.hadoop.metrics2.util.SampleStat; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| /** |
| * Helper class to manage a group of mutable rate metrics. |
| * |
| * Each thread will maintain a local rate count, and upon snapshot, |
| * these values will be aggregated into a global rate. This class |
| * should only be used for long running threads, as any metrics |
| * produced between the last snapshot and the death of a thread |
| * will be lost. This allows for significantly higher concurrency |
| * than {@link MutableRates}. See HADOOP-24420. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class MutableRatesWithAggregation extends MutableMetric { |
| static final Logger LOG = |
| LoggerFactory.getLogger(MutableRatesWithAggregation.class); |
| private final Map<String, MutableRate> globalMetrics = |
| new ConcurrentHashMap<>(); |
| private final Set<Class<?>> protocolCache = new HashSet<>(); |
| |
| private final ConcurrentLinkedDeque<WeakReference<ConcurrentMap<String, ThreadSafeSampleStat>>> |
| weakReferenceQueue = new ConcurrentLinkedDeque<>(); |
| private final ThreadLocal<ConcurrentMap<String, ThreadSafeSampleStat>> |
| threadLocalMetricsMap = new ThreadLocal<>(); |
| // prefix for metric name |
| private String typePrefix = ""; |
| |
| /** |
| * Initialize the registry with all the methods in a protocol |
| * so they all show up in the first snapshot. |
| * Convenient for JMX implementations. |
| * @param protocol the protocol class |
| */ |
| public void init(Class<?> protocol) { |
| if (protocolCache.contains(protocol)) { |
| return; |
| } |
| protocolCache.add(protocol); |
| for (Method method : protocol.getMethods()) { |
| String name = method.getName(); |
| LOG.debug(name); |
| addMetricIfNotExists(name); |
| } |
| } |
| |
| /** |
| * Initialize the registry with all rate names passed in. |
| * This is an alternative to the above init function since this metric |
| * can be used more than just for rpc name. |
| * @param names the array of all rate names |
| */ |
| public void init(String[] names) { |
| for (String name : names) { |
| addMetricIfNotExists(name); |
| } |
| } |
| |
| /** |
| * Add a rate sample for a rate metric. |
| * @param name of the rate metric |
| * @param elapsed time |
| */ |
| public void add(String name, long elapsed) { |
| ConcurrentMap<String, ThreadSafeSampleStat> localStats = |
| threadLocalMetricsMap.get(); |
| if (localStats == null) { |
| localStats = new ConcurrentHashMap<>(); |
| threadLocalMetricsMap.set(localStats); |
| weakReferenceQueue.add(new WeakReference<>(localStats)); |
| } |
| ThreadSafeSampleStat stat = localStats.get(name); |
| if (stat == null) { |
| stat = new ThreadSafeSampleStat(); |
| localStats.put(name, stat); |
| } |
| stat.add(elapsed); |
| } |
| |
| @Override |
| public synchronized void snapshot(MetricsRecordBuilder rb, boolean all) { |
| Iterator<WeakReference<ConcurrentMap<String, ThreadSafeSampleStat>>> iter = |
| weakReferenceQueue.iterator(); |
| while (iter.hasNext()) { |
| ConcurrentMap<String, ThreadSafeSampleStat> map = iter.next().get(); |
| if (map == null) { |
| // Thread has died; clean up its state |
| iter.remove(); |
| } else { |
| aggregateLocalStatesToGlobalMetrics(map); |
| } |
| } |
| for (MutableRate globalMetric : globalMetrics.values()) { |
| globalMetric.snapshot(rb, all); |
| } |
| } |
| |
| /** |
| * Collects states maintained in {@link ThreadLocal}, if any. |
| */ |
| synchronized void collectThreadLocalStates() { |
| final ConcurrentMap<String, ThreadSafeSampleStat> localStats = |
| threadLocalMetricsMap.get(); |
| if (localStats != null) { |
| aggregateLocalStatesToGlobalMetrics(localStats); |
| } |
| } |
| |
| /** |
| * Aggregates the thread's local samples into the global metrics. The caller |
| * should ensure its thread safety. |
| */ |
| private void aggregateLocalStatesToGlobalMetrics( |
| final ConcurrentMap<String, ThreadSafeSampleStat> localStats) { |
| for (Map.Entry<String, ThreadSafeSampleStat> entry : localStats |
| .entrySet()) { |
| String name = entry.getKey(); |
| MutableRate globalMetric = addMetricIfNotExists(name); |
| entry.getValue().snapshotInto(globalMetric); |
| } |
| } |
| |
| Map<String, MutableRate> getGlobalMetrics() { |
| return globalMetrics; |
| } |
| |
| private synchronized MutableRate addMetricIfNotExists(String name) { |
| MutableRate metric = globalMetrics.get(name); |
| if (metric == null) { |
| metric = new MutableRate(name + typePrefix, name + typePrefix, false); |
| metric.setUpdateTimeStamp(true); |
| globalMetrics.put(name, metric); |
| } |
| return metric; |
| } |
| |
| private static class ThreadSafeSampleStat { |
| |
| private SampleStat stat = new SampleStat(); |
| |
| synchronized void add(double x) { |
| stat.add(x); |
| } |
| |
| synchronized void snapshotInto(MutableRate metric) { |
| if (stat.numSamples() > 0) { |
| metric.add(stat.numSamples(), Math.round(stat.total())); |
| stat.reset(); |
| } |
| } |
| } |
| |
| public void init(Class<?> protocol, String prefix) { |
| this.typePrefix = prefix; |
| init(protocol); |
| } |
| |
| } |