Package org.apache.flink.table.planner.plan.nodes.exec.processor

Class ForwardHashExchangeProcessor

java.lang.Object

org.apache.flink.table.planner.plan.nodes.exec.processor.ForwardHashExchangeProcessor

All Implemented Interfaces:

ExecNodeGraphProcessor

public class ForwardHashExchangeProcessor
extends Object
implements ExecNodeGraphProcessor

A ExecNodeGraphProcessor which finds all ExecNodes that require hash distribution, but its input has no hash Exchange node. Currently, the hash distribution is satisfied by its none exchange inputs with FORWARD partitioner (the node and its input has the same parallelism). Once the parallelism is changed, the FORWARD behavior will be broken, and the result will be wrong.

In order to meet the needs of flexible parallelism changing by adaptive scheduler, a special BatchExecExchange (with KEEP_INPUT_AS_IS distribution flag) will be added for the ExecNode as its input. And then the StreamingJobGraphGenerator will decide which partitioner can be used when dynamic-graph is enabled: FORWARD partitioner if nodes are chainable, else HASH partitioner.

Its works only for batch job when dynamic-graph is enabled.

Constructor Summary

Constructors

Constructor	Description
ForwardHashExchangeProcessor()

Method Summary

Modifier and Type	Method	Description
ExecNodeGraph	process(ExecNodeGraph execGraph, ProcessorContext context)	Given an ExecNodeGraph, process it and return the result ExecNodeGraph.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ForwardHashExchangeProcessor

public ForwardHashExchangeProcessor()

Method Details

process

public ExecNodeGraph process(ExecNodeGraph execGraph,
 ProcessorContext context)

Description copied from interface: ExecNodeGraphProcessor

Given an ExecNodeGraph, process it and return the result ExecNodeGraph.

Specified by:

process in interface ExecNodeGraphProcessor