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Sean Quah updated KAFKA-19405: ------------------------------ Description: Consider a new group with members joining. Each member is subscribed to the same topic. 1. The first member is assigned partitions \{1,2,3,4,5} 2. A second member joins and has a target assignment of \{3,4,5}. 3. The first member revokes partition 3. 4. The second member is assigned partition 3 in a heartbeat response. 5. A third member joins. The second member's target assignment is now \{5}. 6. The second member is assigned no partitions in a heartbeat response. 7. Later, the second member is assigned partition 5 in a heartbeat response, once it has been revoked by the first member. >From the perspective of the second member, it was assigned partition 3, then >the assignment changed to partition 5. >From the perspective of the broker, the second member's target assignment was >\{3,4,5}, then \{5}. If assignor stickiness favored owned partitions, then the second member would see a more stable assignment and keep partition 3. was: Imagine a new group with members joining. Each member is subscribed to the same topic. 1. The first member is assigned partitions \{1,2,3,4,5} 2. A second member joins and has a target assignment of \{3,4,5}. 3. The first member revokes partition 3. 4. The second member is assigned partition 3 in a heartbeat response. 5. A third member joins. The second member's target assignment is now \{5}. 6. The second member is assigned no partitions in a heartbeat response. 7. Later, the second member is assigned partition 5 in a heartbeat response, once it has been revoked by the first member. >From the perspective of the second member, it was assigned partition 3, then >the assignment changed to partition 5. >From the perspective of the broker, the second member's target assignment was >\{3,4,5}, then \{5}. If assignor stickiness favored owned partitions, then the second member would see a more stable assignment and keep partition 3. > Assignor stickiness should keep owned partitions instead of partitions > waiting to be revoked by another member > --------------------------------------------------------------------------------------------------------------- > > Key: KAFKA-19405 > URL: https://issues.apache.org/jira/browse/KAFKA-19405 > Project: Kafka > Issue Type: Improvement > Components: group-coordinator > Reporter: Sean Quah > Assignee: Sean Quah > Priority: Minor > > Consider a new group with members joining. Each member is subscribed to the > same topic. > > 1. The first member is assigned partitions \{1,2,3,4,5} > 2. A second member joins and has a target assignment of \{3,4,5}. > 3. The first member revokes partition 3. > 4. The second member is assigned partition 3 in a heartbeat response. > 5. A third member joins. The second member's target assignment is now \{5}. > 6. The second member is assigned no partitions in a heartbeat response. > 7. Later, the second member is assigned partition 5 in a heartbeat response, > once it has been revoked by the first member. > > From the perspective of the second member, it was assigned partition 3, then > the assignment changed to partition 5. > From the perspective of the broker, the second member's target assignment was > \{3,4,5}, then \{5}. > > If assignor stickiness favored owned partitions, then the second member would > see a more stable assignment and keep partition 3. -- This message was sent by Atlassian Jira (v8.20.10#820010)