Support Static Membership Protocol

[sandeepkumarcel]

Hi team,

We would like to request support for Static Membership Protocol in the confluent-kafka-javascript client.

This feature is important to us because it allows consumers to retain their member identity across rebalances, significantly reducing the downtime and churn typically caused by frequent consumer group rebalancing.

We currently maintain a fork of kafkajs where we have implemented and rely on static membership. However, we're planning to migrate to the official confluent-kafka-javascript client to align with Confluent's maintained ecosystem and benefit from the performance and feature set of librdkafka.

Static membership support is a key requirement for our migration. Could this feature be prioritized in the roadmap? We'd be happy to contribute or collaborate on this effort if needed.

Thank you for considering this request!

[milindl]

It's already supported, by setting group.instance.id, for example:

  const kafka = new Kafka({
    kafkaJS: {
      brokers: ['<fill>:9092'],
      ssl: true,
      sasl: {
         // ...
      },
    }
  });

  consumer = kafka.consumer({
    kafkaJS: {
      groupId: 'test-group',
    },
    /* Properties from librdkafka can also be used - including group instance id to use static group membership */
   "group.instance.id": <fill>
  });

[vikas-goswami]

Thanks, I must be passing it inside kafkaJS properties.