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• In transactions, the producer collects multiple records in batches. Then a RecordTooLargeException related to a single record leads to failing the entire batch. A custom exception handler in this case may decide on dropping the record and continuing the processing.
• When a user tries to write into a non-existing topic, it returns a retryable error code; with infinite retries, the producer would hang retrying forever. A custom handler in this case could help to break the infinite retry loop.

This KIP introduces an interface that can be implemented by the user to handle the exceptions UnknownTopicOrPartitionException and RecordTooLargeException.

Question: Why do we need an interface for handling the exceptions? Could we have a couple of simple producer configuration options for those two exceptions? 
Answer: We aim at giving the user the flexibility of an interface. For example, facing UnknownTopicOrPartitionException, the user may want to raise an error for some topics but retry it for other topics. Having a configuration option with a fixed set of possibilities does not serve the user's needs.   

Public Interfaces

We introduce the ProducerExceptionHandler interface, which that can be implemented by the user to manage the exception in the desired manner.
To configure their own handler, the user must implement the above introduced interface and add the class name in producer configuration with the key: custom.exception.handler.

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