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 package org.apache.giraph.bsp.checkpoints; 19 20 import org.apache.giraph.conf.GiraphConfiguration; 21 import org.apache.giraph.master.MasterCompute; 22 23 /** 24 * To prevent accidental checkpointing of non-checkpointable app 25 * you may provide implementation of this interface. Most apps are 26 * checkpointable by default, however some apps are not checkpointable, 27 * e.g. apps that use static variables to pass data around between supersteps 28 * or start new threads or use external resources. This interface allows 29 * you to specify if and when your app is checkpointable. 30 */ 31 public interface CheckpointSupportedChecker { 32 33 /** 34 * Does the job support checkpoints? 35 * It is true by default, set it to false if your job uses some 36 * non-checkpointable features: 37 * - static variables for storing data between supersteps. 38 * - starts new threads or uses Timers 39 * - writes output before job is complete, etc 40 * This method is called on master and has access to 41 * job configuration and master compute. 42 * 43 * @param conf giraph configuration 44 * @param masterCompute instance of master compute 45 * @return true if checkpointing on current superstep is supported 46 * by this application. 47 */ 48 boolean isCheckpointSupported(GiraphConfiguration conf, 49 MasterCompute masterCompute); 50 51 }