KafkaConsumer hangs if 'group.id' property is missing

Environment Information

• OS : debian 9.6 (x86_64)
• Node Version : 9.11.1
• NPM Version : 6.5.0
• node-rdkafka version : 2.5.1

Steps to Reproduce Instantiate a KafkaConsumer client without specifying a group.id property.

node-rdkafka Configuration Settings

const rd = require('node-rdkafka');

const options = {
  'metadata.broker.list': 'localhost:9092'
}

const consumer = new rd.KafkaConsumer(options);

consumer.on('ready', () => {
  consumer.subscribe([ 'some-topic' ]);
  consumer.consume((err, message) => {
    console.log(err, message);
  });
});

consumer.connect();
// .... nothing will happens : ready event will never been triggered, nor logging events
// Note: Kafka cluster is healthy

Additional context Kafka client just hangs - no event triggered, no debug message

I would expect KafkaConsumer to throw an error if group.id is missing or to generate a random one.

[subk]

Sure, Thats why I think node-rdkafka should throw an error when ‘group.id’ is missing.

[stale[bot]]

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