@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.");
}
in.setLocalStrategy(
LocalStrategy.COMBININGSORT, in.getLocalStrategyKeys(), in.getLocalStrategySortOrder());
}
return new SingleInputPlanNode(
node,
"Reduce(" + node.getOperator().getName() + ")",
in,
DriverStrategy.SORTED_GROUP_REDUCE,
this.keyList);
} else {
// non forward case. all local properties are killed anyways, so we can safely plug in a
// combiner
Channel toCombiner = new Channel(in.getSource());
toCombiner.setShipStrategy(ShipStrategyType.FORWARD, DataExchangeMode.PIPELINED);
// create an input node for combine with same parallelism as input node
GroupReduceNode combinerNode = ((GroupReduceNode) node).getCombinerUtilityNode();
combinerNode.setParallelism(in.getSource().getParallelism());
SingleInputPlanNode combiner =
new SingleInputPlanNode(
combinerNode,
"Combine(" + node.getOperator().getName() + ")",
toCombiner,
DriverStrategy.SORTED_GROUP_COMBINE);
combiner.setCosts(new Costs(0, 0));
combiner.initProperties(toCombiner.getGlobalProperties(), toCombiner.getLocalProperties());
// set sorting comparator key info
combiner.setDriverKeyInfo(in.getLocalStrategyKeys(), in.getLocalStrategySortOrder(), 0);
// set grouping comparator key info
combiner.setDriverKeyInfo(this.keyList, 1);
Channel toReducer = new Channel(combiner);
toReducer.setShipStrategy(
in.getShipStrategy(),
in.getShipStrategyKeys(),
in.getShipStrategySortOrder(),
in.getDataExchangeMode());
if (in.getShipStrategy() == ShipStrategyType.PARTITION_RANGE) {
toReducer.setDataDistribution(in.getDataDistribution());
}
toReducer.setLocalStrategy(
LocalStrategy.COMBININGSORT, in.getLocalStrategyKeys(), in.getLocalStrategySortOrder());
return new SingleInputPlanNode(
node,
"Reduce (" + node.getOperator().getName() + ")",
toReducer,
DriverStrategy.SORTED_GROUP_REDUCE,
this.keyList);
}
}
