org.apache.samza.system

Interface SystemProducer

public interface SystemProducer

SystemProducers are how Samza writes messages from StreamTasks to outside systems, such as messaging systems like Kafka, or file systems. Implementations are responsible for accepting messages and writing them to their backing systems.

Method Summary

Modifier and Type	Method and Description
void	flush(java.lang.String source) If the SystemProducer buffers messages before sending them to its underlying system, it should flush those messages and leave no messages remaining to be sent.
void	register(java.lang.String source) Registers this producer to send messages from a specified Samza source, such as a StreamTask.
void	send(java.lang.String source, OutgoingMessageEnvelope envelope) Sends a specified message envelope from a specified Samza source.
void	start() Start the SystemProducer.
void	stop() Stop the SystemProducer.

Method Detail

start

void start()

Start the SystemProducer. After this method finishes it should be ready to accept messages received from the send method.

stop

void stop()

Stop the SystemProducer. After this method finished, the system should have completed all necessary work, sent any remaining messages and will not receive any new calls to the send method.

register

void register(java.lang.String source)

Registers this producer to send messages from a specified Samza source, such as a StreamTask.

Parameters:

source - String representing the source of the message.

send

void send(java.lang.String source,
          OutgoingMessageEnvelope envelope)

Sends a specified message envelope from a specified Samza source.

Parameters:

source - String representing the source of the message.

envelope - Aggregate object representing the serialized message to send from the source.

flush

void flush(java.lang.String source)

If the SystemProducer buffers messages before sending them to its underlying system, it should flush those messages and leave no messages remaining to be sent.

Parameters:

source - String representing the source of the message.