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Currently if a transactional producer hits a fatal exception, the caller usually catches the exception and handle it by aborting the transaction by invoking abortTxn(), and closing the the producer, which makes sense and sounds clean. The tricky scenario is that `abortTxn` abortTxn is not a safe call when the producer is already in an error state, which means user has to do another try-catch with the first layer catch block, making the error handling pretty annoying. It is more appropriate and user-friendly to ensure that the transactional producer client does not throw an exception since users already intend to abort the the same exception again while aborting transaction.

Public Interfaces

org/apache/kafka/clients

Proposed Changes

Describe the new thing you want to do in appropriate detail. This may be fairly extensive and have large subsections of its own. Or it may be a few sentences. Use judgement based on the scope of the changeOur proposal is quite straightforward and simple. To avoid throwing same exceptions twice, we can determine whether the producer client is already in error state in abortTxn. If yes, the producer client does nothing. Otherwise it enforces the actual transaction aborting.

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

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Our proposed change can be considered as minor. In users' perspective, they have less exceptions to worry and handle when calling abortTxn. 

Rejected Alternatives