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 */
018package org.apache.hadoop.hbase.regionserver;
019
020import java.util.Map;
021import org.apache.hadoop.hbase.metrics.BaseSource;
022import org.apache.yetus.audience.InterfaceAudience;
023
024/**
025 * This interface will be implemented by a MetricsSource that will export metrics from multiple
026 * users into the hadoop metrics system.
027 */
028@InterfaceAudience.Private
029public interface MetricsUserAggregateSource extends BaseSource {
030
031  /**
032   * The name of the metrics
033   */
034  static final String METRICS_NAME = "Users";
035
036  /**
037   * The name of the metrics context that metrics will be under.
038   */
039  static final String METRICS_CONTEXT = "regionserver";
040
041  /**
042   * Description
043   */
044  static final String METRICS_DESCRIPTION = "Metrics about users connected to the regionserver";
045
046  /**
047   * The name of the metrics context that metrics will be under in jmx
048   */
049  static final String METRICS_JMX_CONTEXT = "RegionServer,sub=" + METRICS_NAME;
050
051  static final String NUM_USERS = "numUsers";
052  static final String NUMBER_OF_USERS_DESC = "Number of users in the metrics system";
053
054  /**
055   * Returns a MetricsUserSource if already exists, or creates and registers one for this user
056   * @param user the user name
057   * @return a metrics user source
058   */
059  MetricsUserSource getOrCreateMetricsUser(String user);
060
061  void deregister(MetricsUserSource toRemove);
062
063  Map<String, MetricsUserSource> getUserSources();
064}