Re: Kafka Producer send offsets to transaction method confusion

Sure, I would love to continue working on this task and provide an interface, I see that someone else has been assigned to Jira recently, please let him know that I like to handle it on my own 🙂

Dnia 20 lutego 2025 03:51:02 CET, "Matthias J. Sax" <mjsax@apache.org> napisał/a:
>Thanks for reaching out. This is actually very good feedback.
>
>In general, it seems that `ConsumerGroupMetadata` should be an interface, not a class, making it impossible for users to create an instance.
>
>Of course, we cannot do anything for older releases, and it seems the JavaDocs do explain it correctly...
>
>But I did file https://issues.apache.org/jira/browse/KAFKA-18836 -- feel free to pick it up if you have interest to contribute a fix for Apache Kafka 4.1 release.
>
>
>-Matthias
>
>
>On 2/19/25 9:17 AM, Paweł Szymczyk wrote:
>> Hello!
>>
>> Recently, I had an opportunity to work with legacy code that was using an
>> old version of the Kafka native producer transactional API. Our goal was to
>> upgrade the code to the newest version and benefit from the upgraded
>> transactional API protocol. Initially, we found code that was highlighted
>> as deprecated (
>> https://kafka.apache.org/25/javadoc/org/apache/kafka/clients/producer/Producer.html#sendOffsetsToTransaction-java.util.Map-java.lang.String-
>> ):
>>
>>> kafkaProducer.sendOffsetsToTransaction(Map.of(new
>>> TopicPartition(record.topic(), record.partition()), new
>>> OffsetAndMetadata(record.offset())), groupId);
>>>
>>
>> Our first approach was to use the non-deprecated API:
>>
>> kafkaProducer.sendOffsetsToTransaction(Map.of(new
>>> TopicPartition(record.topic(), record.partition()), new
>>> OffsetAndMetadata(record.offset())), new ConsumerGroupMetadata(groupId));
>>
>>
>> A few days later, after an extensive testing session, we finally read the
>> new sendOffsetsToTransaction method javadoc and discovered that we needed
>> to retrieve metadata from the Kafka Consumer.
>>
>> From our perspective, this upgrade process was more complicated than
>> expected and requires broad knowledge of the transactional protocol
>> upgrade. Are there any contradictions in making the public
>> ConsumerGroupMetadata(String
>> groupId) constructor deprecated too? It would have given us a clear hint
>> that we were still doing something wrong from the start.
>>
>

Paweł Szymczyk