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;
020
021import org.apache.hadoop.classification.InterfaceAudience;
022import org.apache.hadoop.classification.InterfaceStability;
023
024/**
025 * The JMX interface to the metrics system
026 */
027@InterfaceAudience.Public
028@InterfaceStability.Evolving
029public interface MetricsSystemMXBean {
030  /**
031   * Start the metrics system
032   * @throws MetricsException
033   */
034  public void start();
035
036  /**
037   * Stop the metrics system
038   * @throws MetricsException
039   */
040  public void stop();
041
042  /**
043   * Start metrics MBeans
044   * @throws MetricsException
045   */
046  public void startMetricsMBeans();
047
048  /**
049   * Stop metrics MBeans.
050   * Note, it doesn't stop the metrics system control MBean,
051   * i.e this interface.
052   * @throws MetricsException
053   */
054  public void stopMetricsMBeans();
055
056  /**
057   * @return the current config
058   * Avoided getConfig, as it'll turn into a "Config" attribute,
059   * which doesn't support multiple line values in jconsole.
060   * @throws MetricsException
061   */
062  public String currentConfig();
063}