Hi, I understand that we don’t have to parse the Fetch request body but I was wondering how it can work with several partitions per topic as I don’t see a Partition Array length in the request definition: " topics => topic_id [partitions] TAG_BUFFER topic_id => UUID partitions => partition curr…

Hi @Gad , thanks for your question! The Kafka docs can be unclear and confusing. In this case, [partitions] is a COMPACT_ARRAY, meaning a length field will be included in the request—even though the definition doesn’t explicitly state it. [image] Let me know if you’d like further clarification!

Thank you Andy, makes sense ! Is it the square brackets around partitions that indicate the COMPACT_ARRAY ?

Yep, [partitions] indicates an array, and in newer versions of Kafka APIs, you can assume it’s a COMPACT_ARRAY rather than a standard ARRAY.

Question about dh6: Fetch with no topics

Challenges

system Closed February 12, 2025, 3:55pm 7

This topic was automatically closed 5 days after the last reply. New replies are no longer allowed.

Topic		Replies	Views
Question about fd8: Fetch multiple messages from disk - Expected partitions.length to be 1, got 2 Challenges challenge:kafka	8	123	May 9, 2025
Question about hn6: Fetch with an unknown topic Challenges challenge:kafka	4	85	January 22, 2025
#VT6 (Listing Partitions - List for an unknown topic) Challenges challenge:kafka	5	62	September 3, 2025
Kafka DescribeTopicPartitions request payload lacks bytes Challenges challenge:kafka	3	158	October 22, 2024
Question about HN6 (Fetch with an unknown topic) Challenges challenge:kafka	11	232	October 4, 2024

Question about dh6: Fetch with no topics

Related topics