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.yetus.audience.InterfaceAudience;
022
023/**
024 * Metrics Histogram interface.  Implementing classes will expose computed
025 * quartile values through the metrics system.
026 */
027@InterfaceAudience.Private
028public interface MetricHistogram {
029
030  //Strings used to create metrics names.
031  String NUM_OPS_METRIC_NAME = "_num_ops";
032  String MIN_METRIC_NAME = "_min";
033  String MAX_METRIC_NAME = "_max";
034  String MEAN_METRIC_NAME = "_mean";
035  String MEDIAN_METRIC_NAME = "_median";
036  String TWENTY_FIFTH_PERCENTILE_METRIC_NAME = "_25th_percentile";
037  String SEVENTY_FIFTH_PERCENTILE_METRIC_NAME = "_75th_percentile";
038  String NINETIETH_PERCENTILE_METRIC_NAME = "_90th_percentile";
039  String NINETY_FIFTH_PERCENTILE_METRIC_NAME = "_95th_percentile";
040  String NINETY_EIGHTH_PERCENTILE_METRIC_NAME = "_98th_percentile";
041  String NINETY_NINETH_PERCENTILE_METRIC_NAME = "_99th_percentile";
042  String NINETY_NINE_POINT_NINETH_PERCENTILE_METRIC_NAME = "_99.9th_percentile";
043
044  /**
045   * Add a single value to a histogram's stream of values.
046   * @param value the value to add
047   */
048  void add(long value);
049
050}