hi >From my tests kafka sink in exactly-once and batch runtime will never commit the transaction, leading to not honour the semantic. This is likely by design since records are ack/commited during a checkpoint, which never happens in batch mode. I am missing something or the documentation should warn the users ?
Resources: from https://nightlies.apache.org/flink/flink-docs-release-1.20/docs/connectors/datastream/kafka/#boundedness > Kafka source is designed to support both streaming and batch running mode from https://nightlies.apache.org/flink/flink-docs-release-1.14/docs/connectors/datastream/kafka/#fault-tolerance > AT_LEAST_ONCE: The sink will wait for all outstanding records in the Kafka > buffers to be acknowledged by the Kafka producer on a checkpoint > EXACTLY_ONCE: In this mode, the KafkaSink will write all messages in a Kafka > transaction that will be committed to Kafka on a checkpoint. from https://nightlies.apache.org/flink/flink-docs-release-1.20/docs/dev/datastream/execution_mode/#important-considerations > Unsupported in BATCH mode: Checkpointing and any operations that depend on > checkpointing do not work.
