I’m using confluent-kafka-client. I have one producer producing into a topic with one partition and one consumer within one group ID. First, I create a producer (with default configs) for the topic (if the topic doesn’t exist, I create one with that name)

self.producer = confluent_kafka.Producer({"bootstrap.servers": bootstrap_servers})

Then, I create a consumer and subscribe it to the topic (with default configs, auto.offset.reset="latest")

self.consumer = confluent_kafka.Consumer(
            {"bootstrap.servers": self.bootstrap_servers,
                "group.id": self.group_id},
            logger=logger,
        )
self.consumer.subscribe(self.topic_names, on_assign=print_assignment)
self.consumer.poll(0) # first call

I realized that self.consumer.poll(0) doesn’t register that consumer to the topic since there is no data on that topic yet. After, the producer produces a record. Then, I call
consumer.poll(0) # second call
expecting to get data. However, it returns None. In fact, after data is produced, the call of poll(0) registers the consumer. I can get data by calling the third time.
How to register a consumer to a topic if there is no data on that topic yet?

References: Kafka consumer.poll returns no records