kafka sarama lib how to know how many cosumers in a cosumergroup

Question

I read the consumer group example in here (provided by Shopify/sarama), and I wonder that how would I know how many consumers are in a consumer group, are there any ways I could control the number of consumers?

Thanks a lot

Answer 1

To list the consumers currently assigned to a group, you can use the kafka-consumer-groups .sh shell script. Assuming that $KAFKA_HOME is the root directory of your Kafka installation, you can do:

$KAFKA_HOME/bin/kafka-consumer-groups.sh --describe --group YOURGROUP --zookeeper ZOOKEEPER_HOST:PORT

If you want to list current groups, run the following command:

$KAFKA_HOME/bin/kafka-consumer-groups.sh --list --zookeeper ZOOKEEPER_HOST:PORT

Answer 2

You can use ClusterAdmin interface in Sarama library.

https://pkg.go.dev/github.com/Shopify/sarama#ClusterAdmin