sanha commented on a change in pull request #193: [NEMO-338] SkewSamplingPass URL: https://github.com/apache/incubator-nemo/pull/193#discussion_r258776369
########## File path: compiler/optimizer/src/main/java/org/apache/nemo/compiler/optimizer/pass/compiletime/reshaping/SamplingSkewReshapingPass.java ########## @@ -0,0 +1,137 @@ +/* + * 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.nemo.compiler.optimizer.pass.compiletime.reshaping; + +import org.apache.nemo.common.KeyExtractor; +import org.apache.nemo.common.dag.Edge; +import org.apache.nemo.common.ir.IRDAG; +import org.apache.nemo.common.ir.edge.IREdge; +import org.apache.nemo.common.ir.edge.executionproperty.*; +import org.apache.nemo.common.ir.vertex.IRVertex; +import org.apache.nemo.common.ir.vertex.utility.MessageAggregatorVertex; +import org.apache.nemo.common.ir.vertex.utility.MessageBarrierVertex; +import org.apache.nemo.common.ir.vertex.utility.SamplingVertex; +import org.apache.nemo.compiler.optimizer.pass.compiletime.Requires; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.*; +import java.util.stream.Collectors; + +/** + * Optimizes the PartitionSet property of shuffle edges to handle data skews using the SamplingVertex. + * + * This pass effectively partitions the IRDAG by non-oneToOne edges, clones each subDAG partition using SamplingVertex + * to process sampled data, and executes each cloned partition prior to executing the corresponding original partition. + * + * Suppose the IRDAG is partitioned into three sub-DAGs as follows: Review comment: three sub-DAGs connected with shuffle edges? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
