/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.hadoop.metrics2; /** * Metrics Histogram interface. Implementing classes will expose computed * quartile values through the metrics system. */ public interface MetricHistogram { //Strings used to create metrics names. static final String NUM_OPS_METRIC_NAME = "_num_ops"; static final String MIN_METRIC_NAME = "_min"; static final String MAX_METRIC_NAME = "_max"; static final String MEAN_METRIC_NAME = "_mean"; static final String MEDIAN_METRIC_NAME = "_median"; static final String SEVENTY_FIFTH_PERCENTILE_METRIC_NAME = "_75th_percentile"; static final String NINETY_FIFTH_PERCENTILE_METRIC_NAME = "_95th_percentile"; static final String NINETY_NINETH_PERCENTILE_METRIC_NAME = "_99th_percentile"; /** * Add a single value to a histogram's stream of values. * @param value */ void add(long value); }