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.metrics; 019 020import java.util.Optional; 021import org.apache.hadoop.hbase.HBaseInterfaceAudience; 022import org.apache.yetus.audience.InterfaceAudience; 023import org.apache.yetus.audience.InterfaceStability; 024 025/** 026 * General purpose factory for creating various metrics. 027 */ 028@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC) 029@InterfaceStability.Evolving 030public interface MetricRegistry extends MetricSet { 031 032 /** 033 * Get or construct a {@link Timer} used to measure durations and report rates. 034 * @param name the name of the timer. 035 * @return An instance of {@link Timer}. 036 */ 037 Timer timer(String name); 038 039 /** 040 * Get or construct a {@link Histogram} used to measure a distribution of values. 041 * @param name The name of the Histogram. 042 * @return An instance of {@link Histogram}. 043 */ 044 Histogram histogram(String name); 045 046 /** 047 * Get or construct a {@link Meter} used to measure durations and report distributions (a 048 * combination of a {@link Timer} and a {@link Histogram}. 049 * @param name The name of the Meter. 050 * @return An instance of {@link Meter}. 051 */ 052 Meter meter(String name); 053 054 /** 055 * Get or construct a {@link Counter} used to track a mutable number. 056 * @param name The name of the Counter 057 * @return An instance of {@link Counter}. 058 */ 059 Counter counter(String name); 060 061 /** 062 * Register a {@link Gauge}. The Gauge will be invoked at a period defined by the implementation 063 * of {@link MetricRegistry}. 064 * @param name The name of the Gauge. 065 * @param gauge A callback to compute the current value. 066 * @return the registered gauge, or the existing gauge 067 */ 068 <T> Gauge<T> register(String name, Gauge<T> gauge); 069 070 /** 071 * Registers the {@link Metric} with the given name if there does not exist one with the same 072 * name. Returns the newly registered or existing Metric. 073 * @param name The name of the Metric. 074 * @param metric the metric to register 075 * @return the registered metric, or the existing metrid 076 */ 077 Metric register(String name, Metric metric); 078 079 /** 080 * Registers the {@link Metric}s in the given MetricSet. 081 * @param metricSet set of metrics to register. 082 */ 083 void registerAll(MetricSet metricSet); 084 085 /** 086 * Returns previously registered metric with the name if any. 087 * @param name the name of the metric 088 * @return previously registered metric 089 */ 090 Optional<Metric> get(String name); 091 092 /** 093 * Removes the metric with the given name. 094 * @param name the name of the metric 095 * @return true if the metric is removed. 096 */ 097 boolean remove(String name); 098 099 /** 100 * Return the MetricRegistryInfo object for this registry. 101 * @return MetricRegistryInfo describing the registry. 102 */ 103 @InterfaceAudience.Private 104 MetricRegistryInfo getMetricRegistryInfo(); 105}