[KAFKA-3834] Consumer should not block in poll on coordinator discovery

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: consumer
• Assignee: Jason Gustafson
• Reporter: Jason Gustafson
• Created: 13/Jun/16 17:02
• Updated: 09/Jun/20 05:10
• Resolved: 30/May/18 15:35

Description

Currently we block indefinitely in poll() when discovering the coordinator for the group. Instead, we can return an empty record set when the passed timeout expires. The downside is that it may obscure the underlying problem (which is usually misconfiguration), but users typically have to look at the logs to figure out the problem anyway.

Issue Links

• is duplicated by: KAFKA-5065 AbstractCoordinator.ensureCoordinatorReady() stuck in loop if absent any bootstrap servers
• is duplicated by: KAFKA-6230 KafkaConsumer.poll(0) should not block forever if coordinator is not available
• is duplicated by: KAFKA-6257 KafkaConsumer was hung when bootstrap servers was not existed
• is part of: KAFKA-1894 Avoid long or infinite blocking in the consumer