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.giraph.utils; 20 21 import org.apache.hadoop.mapreduce.Job; 22 23 import java.io.IOException; 24 25 /** Utility methods for dealing with counters */ 26 public class CounterUtils { 27 /** Milliseconds to sleep for while waiting for counter to appear */ 28 private static final int SLEEP_MSECS = 100; 29 30 /** Do not instantiate */ 31 private CounterUtils() { 32 } 33 34 /** 35 * Wait for a counter to appear in a group and then return the name of that 36 * counter. If job finishes before counter appears, return null. 37 * 38 * @param job Job 39 * @param group Name of the counter group 40 * @return Name of the counter inside of the group, or null if job finishes 41 * before counter appears 42 */ 43 public static String waitAndGetCounterNameFromGroup(Job job, String group) { 44 try { 45 while (job.getCounters().getGroup(group).size() == 0) { 46 if (job.isComplete()) { 47 return null; 48 } 49 Thread.sleep(SLEEP_MSECS); 50 } 51 return job.getCounters().getGroup(group).iterator().next().getName(); 52 } catch (IOException | InterruptedException e) { 53 throw new IllegalStateException( 54 "waitAndGetCounterNameFromGroup: Exception occurred", e); 55 } 56 } 57 }