Increase stream threads for Quarkus Kafka Streams

Question

I have written a Quarkus application(version 2.16) with kafka streams in it. There was lag in consumer group count for my application due to huge number of messages in kafka topic. So after checking the logs of the application, I noticed that the streams is using only one thread for processing whole of streams

2023-02-21 01:49:53,933 INFO  [com.git.sample.Example] (streams-app-1cdf32a0-9f2f-4f71-80d0-2c5964a06d47-StreamThread-1) The...

This 1cdf32a0-9f2f-4f71-80d0-2c5964a06d47-StreamThread-1 stream id is same for all the logs related to streams. This case is seen for all the multiple instances of the application. But shouldn't quarkus assign more threads for streams if it has huge load.

In Kafka streams official documentation there is option to set the number of threads for the application (num.stream.threads)

but in Quarkus kafka streams guide (https://quarkus.io/guides/kafka-streams) , I did not find any such application property to increase threads.

I have searched at other places for this but did not find any.

Do anyone know how to increase threads for kafka streams in Quarkus ?

The application is reading from multiple kafka topics but only one stream thread is being used for all operations in streams. Expected is that multiple threads will be used for streams.

Answer 1

It seems that we can use kafka streams properties in Quarkus if we add a prefix kafka-streams, so after adding the property as kafka-streams.num.stream.threads=2 in application properties of the application then I am able to see logs with two different threads for the streams.