/** * 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.hadoop.mapreduce.v2.app.speculate; import org.apache.hadoop.mapreduce.v2.api.records.JobId; import org.apache.hadoop.mapreduce.v2.api.records.TaskId; import org.apache.hadoop.mapreduce.v2.app.AppContext; import org.apache.hadoop.mapreduce.v2.app.job.Job; import org.apache.hadoop.mapreduce.v2.app.job.Task; public class TaskSpeculationPredicate { boolean canSpeculate(AppContext context, TaskId taskID) { // This class rejects speculating any task that already has speculations, // or isn't running. // Subclasses should call TaskSpeculationPredicate.canSpeculate(...) , but // can be even more restrictive. JobId jobID = taskID.getJobId(); Job job = context.getJob(jobID); Task task = job.getTask(taskID); return task.getAttempts().size() == 1; } }