1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.hadoop.metrics2; 20 21 /** 22 * Metrics Histogram interface. Implementing classes will expose computed 23 * quartile values through the metrics system. 24 */ 25 public interface MetricHistogram { 26 27 //Strings used to create metrics names. 28 String NUM_OPS_METRIC_NAME = "_num_ops"; 29 String MIN_METRIC_NAME = "_min"; 30 String MAX_METRIC_NAME = "_max"; 31 String MEAN_METRIC_NAME = "_mean"; 32 String MEDIAN_METRIC_NAME = "_median"; 33 String SEVENTY_FIFTH_PERCENTILE_METRIC_NAME = "_75th_percentile"; 34 String NINETY_FIFTH_PERCENTILE_METRIC_NAME = "_95th_percentile"; 35 String NINETY_NINETH_PERCENTILE_METRIC_NAME = "_99th_percentile"; 36 37 /** 38 * Add a single value to a histogram's stream of values. 39 * @param value 40 */ 41 void add(long value); 42 43 }