Hi Pierre, Try using kafka-reassign-partitions.sh to reassign partitions to different replicas you like. ref: https://kafka.apache.org/documentation/#basic_ops_automigrate
Luke On Mon, Nov 14, 2022 at 3:55 PM Pierre Coquentin <pierre.coquen...@gmail.com> wrote: > Hello, > We have a Kafka cluster (2.4.1) with a replication factor of 3. I notice > when we stop a broker that only one broker takes all the load from the > missing broker and becomes the leader to all partitions. > I would have thought that Kafka would split the load evenly among the > remaining brokers. > > So if I have this kind of configuration > Topic: test > Partition 0 - Leader: 1 - Replicas: 1,2,3 - Isr: 1,2,3 > Partition 1 - Leader: 2 - Replicas: 2,3,1 - Isr: 1,2,3 > Partition 2 - Leader: 3 - Replicas: 3,1,2 - Isr: 1,2,3 > Partition 3 - Leader: 1 - Replicas: 1,2,3 - Isr: 1,2,3 > Partition 4 - Leader: 2 - Replicas: 2,3,1 - Isr: 1,2,3 > Partition 5 - Leader: 3 - Replicas: 3,1,2 - Isr: 1,2,3 > > If I stop broker 1, I want something like this (load is split evenly among > broker 2 and 3): > Topic: test > Partition 0 - Leader: 2 - Replicas: 1,2,3 - Isr: 2,3 > Partition 1 - Leader: 2 - Replicas: 2,3,1 - Isr: 2,3 > Partition 2 - Leader: 3 - Replicas: 3,1,2 - Isr: 2,3 > Partition 3 - Leader: 3 - Replicas: 1,2,3 - Isr: 2,3 > Partition 4 - Leader: 2 - Replicas: 2,3,1 - Isr: 2,3 > Partition 5 - Leader: 3 - Replicas: 3,1,2 - Isr: 2,3 > > What I observe is currently this (broker 2 takes all the load from broker > 1): > Partition 0 - Leader: 2 - Replicas: 1,2,3 - Isr: 2,3 > Partition 1 - Leader: 2 - Replicas: 2,3,1 - Isr: 2,3 > Partition 2 - Leader: 3 - Replicas: 3,1,2 - Isr: 2,3 > Partition 3 - Leader: 2 - Replicas: 1,2,3 - Isr: 2,3 > Partition 4 - Leader: 2 - Replicas: 2,3,1 - Isr: 2,3 > Partition 5 - Leader: 3 - Replicas: 3,1,2 - Isr: 2,3 > > My concern here is that at all times, a broker should not exceed 50% of its > network bandwidth which could be a problem in my case. > Is there a way to change this behavior (manually by forcing a leader, > programmatically, or by configuration)? > From my understanding, the script kafka-leader-election.sh allows only to > set the preferred (the first in the list of replicas) or uncleaned > (replicas not in sync can become a leader). > Regards, > > Pierre >
