RivenSun created KAFKA-13814: -------------------------------- Summary: Improve documentation of KafkaConsumer's group.id parameter Key: KAFKA-13814 URL: https://issues.apache.org/jira/browse/KAFKA-13814 Project: Kafka Issue Type: Improvement Components: documentation Reporter: RivenSun
With KIP-289 and `GroupCoordinator.isValidGroupId(...)` method, we can conclude that for KafkaConsumer: 1. For consumers using the group management mechanism, `group.id` must be non-null and non-empty string 2. `group.id` can be set to empty string only in assign mode [https://kafka.apache.org/documentation/#consumerconfigs_group.id] So I suggest improving the parameter documentation as follows: A unique string that identifies the consumer group this consumer belongs to. This property is required if the consumer uses either the group management functionality by using {{subscribe(topic)}} or the Kafka-based offset management strategy. -> A unique string that identifies the consumer group this consumer belongs to. This property is required if the consumer uses either the group management functionality by using {{subscribe(topic)}} or the Kafka-based offset management strategy, *the value must be a non-null and non-empty string.* *`group.id` can be set to an empty string only the consumer uses {{assign(topic).}}* -- This message was sent by Atlassian Jira (v8.20.1#820001)