When is the status of isr updated

[Jie Li <ja...@gmail.com>]

Hello,

We observed in some cases the isr were outdated: healthy brokers may be
missing from isr, or dead brokers may still stay in isr for a while.  My
guess is the list of isr is only updated upon a few events, e.g. when a
message is written to the partition, or when the brokers come online?

Thanks,
Jie

Re: When is the status of isr updated

[Neha Narkhede <ne...@gmail.com>]

Hi Jie,

If you see frequent changes in the ISR for some partitions, you can follow
the recommendation
here<https://cwiki.apache.org/confluence/display/KAFKA/FAQ#FAQ-HowtoreducechurnsinISR?WhendoesabrokerleavetheISR?>to
address that.

Thanks,
Neha


On Wed, Mar 26, 2014 at 11:11 AM, Guozhang Wang <wa...@gmail.com> wrote:

> Hello Jie,
>
> Yes, the ISR shrinking is handled in a background thread which will
> periodically check the status of each replica and probably kick them out of
> ISR if they are not in-sync with the leader. You can tune the frequency in
> this broker config:
>
> replica.lag.time.max.ms
>
> The ISR expanding is handled by the leader of the partition whenever it
> receives a fetch request from the followers, checking if the follower has
> already caught up.
>
> Guozhang
>
>
> On Tue, Mar 25, 2014 at 10:06 PM, Jie Li <ja...@gmail.com> wrote:
>
> > Hello,
> >
> > We observed in some cases the isr were outdated: healthy brokers may be
> > missing from isr, or dead brokers may still stay in isr for a while.  My
> > guess is the list of isr is only updated upon a few events, e.g. when a
> > message is written to the partition, or when the brokers come online?
> >
> > Thanks,
> > Jie
> >
>
>
>
> --
> -- Guozhang
>

Re: When is the status of isr updated

[Guozhang Wang <wa...@gmail.com>]

Hello Jie,

Yes, the ISR shrinking is handled in a background thread which will
periodically check the status of each replica and probably kick them out of
ISR if they are not in-sync with the leader. You can tune the frequency in
this broker config:

replica.lag.time.max.ms

The ISR expanding is handled by the leader of the partition whenever it
receives a fetch request from the followers, checking if the follower has
already caught up.

Guozhang


On Tue, Mar 25, 2014 at 10:06 PM, Jie Li <ja...@gmail.com> wrote:

> Hello,
>
> We observed in some cases the isr were outdated: healthy brokers may be
> missing from isr, or dead brokers may still stay in isr for a while.  My
> guess is the list of isr is only updated upon a few events, e.g. when a
> message is written to the partition, or when the brokers come online?
>
> Thanks,
> Jie
>



-- 
-- Guozhang