DataNodeActivityMBean.java
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上传日期:2018-01-08
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- /**
- * 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.hdfs.server.datanode.metrics;
- import java.util.Random;
- import javax.management.ObjectName;
- import org.apache.hadoop.metrics.util.MBeanUtil;
- import org.apache.hadoop.metrics.util.MetricsDynamicMBeanBase;
- import org.apache.hadoop.metrics.util.MetricsRegistry;
- /**
- *
- * This is the JMX MBean for reporting the DataNode Activity.
- * The MBean is register using the name
- * "hadoop:service=DataNode,name=DataNodeActivity-<storageid>"
- *
- * Many of the activity metrics are sampled and averaged on an interval
- * which can be specified in the metrics config file.
- * <p>
- * For the metrics that are sampled and averaged, one must specify
- * a metrics context that does periodic update calls. Most metrics contexts do.
- * The default Null metrics context however does NOT. So if you aren't
- * using any other metrics context then you can turn on the viewing and averaging
- * of sampled metrics by specifying the following two lines
- * in the hadoop-meterics.properties file:
- * <pre>
- * dfs.class=org.apache.hadoop.metrics.spi.NullContextWithUpdateThread
- * dfs.period=10
- * </pre>
- *<p>
- * Note that the metrics are collected regardless of the context used.
- * The context with the update thread is used to average the data periodically
- *
- *
- *
- * Impl details: We use a dynamic mbean that gets the list of the metrics
- * from the metrics registry passed as an argument to the constructor
- */
- public class DataNodeActivityMBean extends MetricsDynamicMBeanBase {
- final private ObjectName mbeanName;
- private Random rand = new Random();
- public DataNodeActivityMBean(final MetricsRegistry mr, final String storageId) {
- super(mr, "Activity statistics at the DataNode");
- String storageName;
- if (storageId.equals("")) {// Temp fix for the uninitialized storage
- storageName = "UndefinedStorageId" + rand.nextInt();
- } else {
- storageName = storageId;
- }
- mbeanName = MBeanUtil.registerMBean("DataNode", "DataNodeActivity-" + storageName, this);
- }
-
- public void shutdown() {
- if (mbeanName != null)
- MBeanUtil.unregisterMBean(mbeanName);
- }
- }