Status

Current state: Under Discussion

Discussion thread: TBD

JIRA: 

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

Kafka Producer supports transactional semantics since 0.11, including the following APIs:

• InitTransaction for transactional producer identity initialization
• beginTransaction to start a new transaction 
• sendOffsetsToTransaction to commit consumer offsets advanced within the current transaction
• commitTransaction commit the ongoing transaction
• abortTransaction abort the ongoing transaction

Public Interfaces

We should add a new exception type called TransactionStateCorruptedException, which wraps non-fatal retriable producer txn exception.

public class TransactionStateCorruptedException extends ApiException {

    public TransactionStateCorruptedException(String message, Throwable cause) {
        super(msg, cause);
    }
}

Proposed Changes

Below is a full list of exception types that could be thrown from producer API as of today

1. ProducerFencedException
2. InvalidProducerEpochException
3. KafkaException, which potentially wraps the following exceptions:
   1. IllegalStateException
   2. InvalidPidMappingException
   3. TransactionAbortedException
   4. ClusterAuthorizationException
   5. UnknownProducerIdException
   6. TransactionalIdAuthorizationException
   7. UnsupportedVersionException
   8. AuthenticationException
   9. UnsupportedForMessageFormatException
   10. RuntimeException for detecting more than one inflight request
   11. InvalidRecordException
   12. InvalidRequiredAcksException
   13. NotEnoughReplicasAfterAppendException
   14. NotEnoughReplicasException
   15. RecordBatchTooLargeException
   16. InvalidTopicException
   17. CorruptRecordException
   18. UnknownTopicOrPartitionException
   19. NotLeaderOrFollowerException
   20. KafkaException
       1. indicates retriable idempotent sequence
       2. indicates fatal transactional sequence
       3. indicates Producer closed
       4. unknown reason
   21. TimeoutException which 

Compatibility, Deprecation, and Migration Plan

• What impact (if any) will there be on existing users?
• If we are changing behavior how will we phase out the older behavior?
• If we need special migration tools, describe them here.
• When will we remove the existing behavior?

Rejected Alternatives

If there are alternative ways of accomplishing the same thing, what were they? The purpose of this section is to motivate why the design is the way it is and not some other way.