| /* |
| * 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.giraph.utils; |
| |
| import org.apache.hadoop.mapreduce.Job; |
| |
| import java.io.IOException; |
| |
| /** Utility methods for dealing with counters */ |
| public class CounterUtils { |
| /** Milliseconds to sleep for while waiting for counter to appear */ |
| private static final int SLEEP_MSECS = 100; |
| |
| /** Do not instantiate */ |
| private CounterUtils() { |
| } |
| |
| /** |
| * Wait for a counter to appear in a group and then return the name of that |
| * counter. If job finishes before counter appears, return null. |
| * |
| * @param job Job |
| * @param group Name of the counter group |
| * @return Name of the counter inside of the group, or null if job finishes |
| * before counter appears |
| */ |
| public static String waitAndGetCounterNameFromGroup(Job job, String group) { |
| try { |
| while (job.getCounters().getGroup(group).size() == 0) { |
| if (job.isComplete()) { |
| return null; |
| } |
| Thread.sleep(SLEEP_MSECS); |
| } |
| return job.getCounters().getGroup(group).iterator().next().getName(); |
| } catch (IOException | InterruptedException e) { |
| throw new IllegalStateException( |
| "waitAndGetCounterNameFromGroup: Exception occurred", e); |
| } |
| } |
| } |