Does Kafka elect new follower when the original follower is down?

["Ramanan, Buvana (Nokia - US/Murray Hill)" <bu...@nokia-bell-labs.com>]

Hello,

I have a 6 broker cluster, configured with auto.leader.rebalance.enable=false. The broker ids are 1 thru 6.

I have about 160 partitions for which I assigned the replicas to be 1,2,3 (1 is the leader). When broker-2 underwent a controlled shutdown, the 'kafka-topics.sh -describe' command showed the ISRs for these partitions to be 1,3, which is an expected outcome.

In case broker-2 is never going to come back alive, will Kafka be able to automatically elect a new follower in the place of broker-2? In other words, just like how a new leader is elected for a partition when its leader goes down, is there a possibility that a new follower is chosen from the list of available brokers?

I understand that I can manually specify a new replica set and use kafka-reassign-partition.sh to execute the reassignment. But I am looking to see if Kafka does any follower assignment by itself.

Thanks,
Buvana

Re: Does Kafka elect new follower when the original follower is down?

[Manikumar <ma...@gmail.com>]

As of now, kafka doesn't have the capability to automatically migrate
followers to other brokers.
We have to use kafka-reassign-partition.sh script.

On Sat, Apr 8, 2017 at 2:15 AM, Ramanan, Buvana (Nokia - US/Murray Hill) <
buvana.ramanan@nokia-bell-labs.com> wrote:

> Hello,
>
> I have a 6 broker cluster, configured with auto.leader.rebalance.enable=false.
> The broker ids are 1 thru 6.
>
> I have about 160 partitions for which I assigned the replicas to be 1,2,3
> (1 is the leader). When broker-2 underwent a controlled shutdown, the
> 'kafka-topics.sh -describe' command showed the ISRs for these partitions to
> be 1,3, which is an expected outcome.
>
> In case broker-2 is never going to come back alive, will Kafka be able to
> automatically elect a new follower in the place of broker-2? In other
> words, just like how a new leader is elected for a partition when its
> leader goes down, is there a possibility that a new follower is chosen from
> the list of available brokers?
>
> I understand that I can manually specify a new replica set and use
> kafka-reassign-partition.sh to execute the reassignment. But I am looking
> to see if Kafka does any follower assignment by itself.
>
> Thanks,
> Buvana
>
>
>