How to skip control batch messages?

[rhasanoff]

Hi @mostafa,
When consuming messages from kafka with xk6-reader, I get events like this:
{\"value\":[0,0,0,0,0,0],\"topic\":\"notification\",\"partition\":0,\"offset\":1,\"time\":\"2023-11-15T14:16:05Z\",\"highWaterMark\":2,\"headers\":{},\"key\":[0,0,0,1]}

When I consume messages with kafka-console-consume I don't see these events. But when I checked in the UI I saw events are 2 offset apart. After reading this article, it was clear that these are control batch messages. "When using transactions, Kafka insert "control batches" in the logs to indicate if messages were part of a transaction."

My question is if it's possible to skip reading these kind of empty contolbatch messages?

[mostafa]

Hey @rhasanoff,

This extension uses kafka-go underneath and kafka-go doesn't support skipping those messages yet. There is a long-awaited unmerged PR for the specific thing you're asking, so consider skipping them in JS code for now, or give them a hand in moving that PR forward.