Github user ramkrish86 commented on a diff in the pull request: https://github.com/apache/flink/pull/1553#discussion_r53659650 --- Diff: flink-optimizer/src/main/java/org/apache/flink/optimizer/operators/GroupReduceWithCombineProperties.java --- @@ -87,19 +92,39 @@ public DriverStrategy getStrategy() { return DriverStrategy.SORTED_GROUP_REDUCE; } - @Override public SingleInputPlanNode instantiate(Channel in, SingleInputNode node) { if (in.getShipStrategy() == ShipStrategyType.FORWARD) { // adjust a sort (changes grouping, so it must be for this driver to combining sort - if (in.getLocalStrategy() == LocalStrategy.SORT) { - if (!in.getLocalStrategyKeys().isValidUnorderedPrefix(this.keys)) { - throw new RuntimeException("Bug: Inconsistent sort for group strategy."); + if(in.getSource().getOptimizerNode() instanceof PartitionNode) { + // Inject a combiner before the partition node + Channel toCombiner = new Channel(in.getSource()); + toCombiner.setShipStrategy(ShipStrategyType.FORWARD, DataExchangeMode.PIPELINED); + GroupReduceNode combinerNode = ((GroupReduceNode) node).getCombinerUtilityNode(); + combinerNode.setParallelism(in.getSource().getParallelism()); + if(toCombiner.getSource().getInputs().iterator().hasNext()) { + Channel source = toCombiner.getSource().getInputs().iterator().next(); + // A combiner plan node is created with the map as the input + SingleInputPlanNode combiner = new SingleInputPlanNode(combinerNode, "Combine("+node.getOperator() --- End diff -- Thanks for all the comments. Checking one by one. I have few questions. Let me get back to you after fixing the other comments. Sorry about the formatting things. I will take care from next time so that they are not repeated.
--- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. ---