io.ray.streaming.api.function

Interface Function

All Superinterfaces:

Serializable

All Known Subinterfaces:

AggregateFunction<I,A,O>, FilterFunction<T>, FlatMapFunction<T,R>, JoinFunction<T,O,R>, KeyFunction<T,K>, MapFunction<T,R>, Partition<T>, ProcessFunction<T>, ReduceFunction<T>, RichFunction, SinkFunction<T>, SourceFunction<T>

All Known Implementing Classes:

BroadcastPartition, CollectionSourceFunction, ForwardPartition, KeyPartition, PythonFunction, PythonPartition, RoundRobinPartition

public interface Function
extends Serializable

Interface of streaming functions.

Method Summary

Modifier and Type	Method and Description
default void	loadCheckpoint(Serializable checkpointObject) This method will be called by framework when a worker died and been restarted.
default Serializable	saveCheckpoint() This method will be called periodically by framework, you should return a a serializable object which represents function state, framework will help you to serialize this object, save it to storage, and load it back when in fail-over through.

Method Detail

saveCheckpoint

default Serializable saveCheckpoint()

This method will be called periodically by framework, you should return a a serializable object which represents function state, framework will help you to serialize this object, save it to storage, and load it back when in fail-over through. loadCheckpoint(Serializable).

Returns:

A serializable object which represents function state.

loadCheckpoint

default void loadCheckpoint(Serializable checkpointObject)

This method will be called by framework when a worker died and been restarted. We will pass the last object you returned in saveCheckpoint() when doing checkpoint, you are responsible to load this object back to you function.

Parameters:

checkpointObject - the last object you returned in saveCheckpoint()