Question about controller behavior when fenced

[Andrew Grant <an...@gmail.com>]

Hi all,

I had a question about controller behavior when fenced. From my
understanding epoch numbers are used to fence brokers who might think
they're still the controller but really in the meantime a new broker has
been elected as the new controller. My question is, how does a broker
realize it's no longer the controller? And when it does realize this, does
it shutdown or does it maybe log something and continue on with its other
duties? I suspect the latter but wanted to check.

Links to any resources that might answer the question would also be
helpful!!

Thanks,
Andrew

-- 
Andrew Grant
8054482621

Re: Question about controller behavior when fenced

[Neeraj Vaidya <ne...@yahoo.co.in.INVALID>]

 Hi Andrew,
Every broker receives a notification about the /controller znode being created and will also receive the latest epoch.
The old controller will get some partitions assigned as a result of it being considered as part of the cluster, by the new controller. This is the normal partition allocation roles/duties of a controller.
The old controller will not shutdown. It will become one of the non-controller brokers, if I may call it.

Regards,
Neeraj
     On Thursday, 30 September, 2021, 12:12:08 am GMT+10, Andrew Grant <an...@gmail.com> wrote:  
 
 Hi all,

I had a question about controller behavior when fenced. From my
understanding epoch numbers are used to fence brokers who might think
they're still the controller but really in the meantime a new broker has
been elected as the new controller. My question is, how does a broker
realize it's no longer the controller? And when it does realize this, does
it shutdown or does it maybe log something and continue on with its other
duties? I suspect the latter but wanted to check.

Links to any resources that might answer the question would also be
helpful!!

Thanks,
Andrew

-- 
Andrew Grant
8054482621