Adem Efe Gencer created KAFKA-9930: -------------------------------------- Summary: Prevent ReplicaFetcherThread from throwing UnknownTopicOrPartitionException upon topic creation and deletion. Key: KAFKA-9930 URL: https://issues.apache.org/jira/browse/KAFKA-9930 Project: Kafka Issue Type: Bug Components: logging Affects Versions: 2.5.0, 2.4.0, 2.3.0, 2.2.0, 2.1.0, 2.0.0, 1.1.0, 1.0.0, 0.11.0.0, 0.10.0.0 Reporter: Adem Efe Gencer Assignee: Adem Efe Gencer
When does UnknownTopicOrPartitionException typically occur? * Upon a topic creation, a follower broker of a new partition starts replica fetcher before the prospective leader broker of the new partition receives the leadership information from the controller. Apache Kafka has a an open issue about this (see KAFKA-6221) * Upon a topic deletion, a follower broker of a to-be-deleted partition starts replica fetcher after the leader broker of the to-be-deleted partition processes the deletion information from the controller. * As expected, clusters with frequent topic creation and deletion report UnknownTopicOrPartitionException with relatively higher frequency. What is the impact? * Exception tracking systems identify the error logs with UnknownTopicOrPartitionException as an exception. This results in a lot of noise for a transient issue that is expected to recover by itself and a natural process in Kafka due to its asynchronous state propagation. Why not move it to a lower than warn-level log? * Despite typically being a transient issue, UnknownTopicOrPartitionException may also indicate real issues if it doesn't fix itself after a short period of time. To ensure detection of such scenarios, we set the log level to warn. -- This message was sent by Atlassian Jira (v8.3.4#803005)