A. Sophie Blee-Goldman created KAFKA-16867: ----------------------------------------------
Summary: Streams should run tag-based standby assignment based on rack ids Key: KAFKA-16867 URL: https://issues.apache.org/jira/browse/KAFKA-16867 Project: Kafka Issue Type: Bug Components: streams Reporter: A. Sophie Blee-Goldman In KIP-708, we introduced a tag-based standby task assignment algorithm that runs if the user has configured their clients with "rack aware assignment tags". If no tags are configured, the default load-based standby task assignment algorithm is run instead. In KIP-924 we introduced a different kind of rack-aware assignment logic which is based on the "rack.id" of the consumers and topic partitions. While this did not replace the tag-based rack-aware assignment of KIP-708 which had different (and opposing) goals, we realized that Streams could leverage the rack.ids to run the tag-based standby task assignment algorithm even if clients were not configured with assignment tags. Unfortunately, during implementation of KIP-924, a bug in the logic meant that the tag-based algorithm was never actually being run based on the rack ids. This bug is present to this day and carried over (intentionally) during the task assignor refactoring of KIP-924. We should still fix this bug so that users can benefit from the resiliency of KIP-708 based on consumer rack ids, even if they did not explicitly opt-in by configuring clients with assignment tags, since KIP-708 is a net benefit with no downside -- This message was sent by Atlassian Jira (v8.20.10#820010)