Reputation: 1618
Let's assume I have a Kafka Cluster of 3 brokers and 3 zookeeper.
I have a single topic accountsTopic
which is setup as replication factor of 3
and ISR of 2
.
If the Leader
dies, kafka will elect the ISR
as leader, but the 3rd one, (which say for arguments sake was not ISR), is it going to serve as a ISR of current leader in this 2 node fail-over setup?
Upvotes: 4
Views: 1111
Reputation: 26895
What happens when the leader dies depends on your configuration.
By default since 0.11, only one of the replicas in-sync can be elected as a leader. If no replicas are in-sync, the partition goes offline. This is favoring consistency over availability.
You can set unclean.leader.election.enable=true
on your brokers and in this case, if no replicas are in-sync, one of the out-of-sync replicas will be elected. This can lead to data loss but is favoring availability. Of course if some replicas are in-sync it will still elect one of them.
Upvotes: 3