com.twitter.heron.api.grouping

Interface CustomStreamGrouping

All Superinterfaces:

java.io.Serializable

public interface CustomStreamGrouping
extends java.io.Serializable

Method Summary

Methods

Modifier and Type	Method and Description
java.util.List<java.lang.Integer>	chooseTasks(java.util.List<java.lang.Object> values) This function implements a custom stream grouping.
void	prepare(TopologyContext context, java.lang.String component, java.lang.String streamId, java.util.List<java.lang.Integer> targetTasks) Tells the stream grouping at runtime the tasks in the target bolt.

Method Detail

prepare

void prepare(TopologyContext context,
           java.lang.String component,
           java.lang.String streamId,
           java.util.List<java.lang.Integer> targetTasks)

Tells the stream grouping at runtime the tasks in the target bolt. This information should be used in chooseTasks to determine the target tasks. It also tells the grouping the metadata on the stream this grouping will be used on.

chooseTasks

java.util.List<java.lang.Integer> chooseTasks(java.util.List<java.lang.Object> values)

This function implements a custom stream grouping. It takes in as input the number of tasks in the target bolt in prepare and returns the tasks to send the tuples to.

Parameters:

values - the values to group on