a (in Flink, a <a href="//nightlies.apache.org/flink/flink-docs-release-1.4/dev/connectors/kafka.html#kafka-producer">KafkaProducer</a>)</li>
</ul>
<p>For the data sink to provide exactly-once guarantees, it must write all data to Kafka within the scope of a transaction. A commit bundles all writes between two checkpoints.</p>
<p>This ensures that writes are rolled back in case of a failure.</p>
<p>However, in a distributed system with multiple, concurrently-running sink tasks, a simple commit or rollback i