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 java.util.Map; 022 023 public interface Instrumentation { 024 025 public interface Cron { 026 027 public Cron start(); 028 029 public Cron stop(); 030 } 031 032 public interface Variable<T> { 033 034 T getValue(); 035 } 036 037 public Cron createCron(); 038 039 public void incr(String group, String name, long count); 040 041 public void addCron(String group, String name, Cron cron); 042 043 public void addVariable(String group, String name, Variable<?> variable); 044 045 //sampling happens once a second 046 public void addSampler(String group, String name, int samplingSize, Variable<Long> variable); 047 048 public Map<String, Map<String, ?>> getSnapshot(); 049 050 }