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    
019    package org.apache.hadoop.metrics2;
020    
021    import org.apache.hadoop.classification.InterfaceAudience;
022    import org.apache.hadoop.classification.InterfaceStability;
023    
024    /**
025     * The JMX interface to the metrics system
026     */
027    @InterfaceAudience.Public
028    @InterfaceStability.Evolving
029    public 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    }