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 */ 018 019 package org.apache.hadoop.lib.service; 020 021 import org.apache.hadoop.classification.InterfaceAudience; 022 023 import java.util.Map; 024 025 @InterfaceAudience.Private 026 public interface Instrumentation { 027 028 public interface Cron { 029 030 public Cron start(); 031 032 public Cron stop(); 033 } 034 035 public interface Variable<T> { 036 037 T getValue(); 038 } 039 040 public Cron createCron(); 041 042 public void incr(String group, String name, long count); 043 044 public void addCron(String group, String name, Cron cron); 045 046 public void addVariable(String group, String name, Variable<?> variable); 047 048 //sampling happens once a second 049 public void addSampler(String group, String name, int samplingSize, Variable<Long> variable); 050 051 public Map<String, Map<String, ?>> getSnapshot(); 052 053 }