[KAFKA-9498] Topic validation during the creation trigger unnecessary TopicChange events

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.6.0
• Assignee: David Jacot
• Reporter: David Jacot
• Created: 03/Feb/20 14:05
• Updated: 26/Feb/20 01:48
• Resolved: 26/Feb/20 01:48

Description

I have found out that the topic validation logic, which is executed when CreateTopicPolicy or when validateOnly is set, triggers unnecessary ChangeTopic events in the controller. In the worst case, it can trigger up to one event per created topic and leads to overloading the controller.

This happens because the validation logic reads all the topics from ZK using the method getAllTopicsInCluster provided by the KafkaZKClient. This method registers a watch every time the topics are read from Zookeeper.

I think that we should make the watch registration optional for this call in oder to avoid this unwanted behaviour.

 

Issue Links

• links to: GitHub Pull Request #8062