org.apache.flink.api.connector.sink2

Interface StatefulSink<InputT,WriterStateT>

Type Parameters:

InputT - The type of the sink's input

WriterStateT - The type of the sink writer's state

All Superinterfaces:

Serializable, Sink<InputT>

All Known Implementing Classes:

AsyncSinkBase, FileSink, KafkaSink

@PublicEvolving
public interface StatefulSink<InputT,WriterStateT>
extends Sink<InputT>

A Sink with a stateful SinkWriter.

The StatefulSink needs to be serializable. All configuration should be validated eagerly. The respective sink writers are transient and will only be created in the subtasks on the taskmanagers.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	StatefulSink.StatefulSinkWriter<InputT,WriterStateT> A SinkWriter whose state needs to be checkpointed.
static interface	StatefulSink.WithCompatibleState A mix-in for StatefulSink that allows users to migrate from a sink with a compatible state to this sink.

Nested classes/interfaces inherited from interface org.apache.flink.api.connector.sink2.Sink

Sink.InitContext

Method Summary

Modifier and Type	Method and Description
StatefulSink.StatefulSinkWriter<InputT,WriterStateT>	createWriter(Sink.InitContext context) Create a StatefulSink.StatefulSinkWriter.
SimpleVersionedSerializer<WriterStateT>	getWriterStateSerializer() Any stateful sink needs to provide this state serializer and implement StatefulSink.StatefulSinkWriter.snapshotState(long) properly.
StatefulSink.StatefulSinkWriter<InputT,WriterStateT>	restoreWriter(Sink.InitContext context, Collection<WriterStateT> recoveredState) Create a StatefulSink.StatefulSinkWriter from a recovered state.

Method Detail

createWriter

StatefulSink.StatefulSinkWriter<InputT,WriterStateT> createWriter(Sink.InitContext context)
                                                           throws IOException

Create a StatefulSink.StatefulSinkWriter.

Specified by:

createWriter in interface Sink<InputT>

Parameters:

context - the runtime context.

Returns:

A sink writer.

Throws:

IOException - for any failure during creation.

restoreWriter

StatefulSink.StatefulSinkWriter<InputT,WriterStateT> restoreWriter(Sink.InitContext context,
                                                                   Collection<WriterStateT> recoveredState)
                                                            throws IOException

Create a StatefulSink.StatefulSinkWriter from a recovered state.

Parameters:

context - the runtime context.

Returns:

A sink writer.

Throws:

IOException - for any failure during creation.

getWriterStateSerializer

SimpleVersionedSerializer<WriterStateT> getWriterStateSerializer()

Any stateful sink needs to provide this state serializer and implement StatefulSink.StatefulSinkWriter.snapshotState(long) properly. The respective state is used in #restoreWriter(InitContext, Collection) on recovery.

Returns:

the serializer of the writer's state type.