[Kea-users] How to best update the KEA configuration on a HA hot-standby KEA setup

[Dan Oachs]

If you really wanted to make sure the standby was serving requests during
that period, you could try starting and stopping via the
ha-maintenance-start command.  I don't do it that frequently, but I run
that command before installing updates and rebooting the main kea server.

--Dan


On Wed, Nov 16, 2022 at 10:42 AM perl-list <perl-list at network1.net> wrote:

> The hot-standby will only start after some criteria are met.  Some of the
> parameters are tunable.  See:
> https://kea.readthedocs.io/en/kea-1.8.1/arm/hooks.html#load-balancing-configuration
> Not sure if you can tune it to start responding within a 30 to 35 second
> window.
>
> We just modify the config on disk and then restart the kea process, but
> then we aren't doing anything special with databases or anything, just the
> JSON config in a single file.  We also aren't changing the config and
> restarting every 5 minutes.
>
> ----- Original Message -----
> > From: "Veronique Lefebure" <Veronique.Lefebure at cern.ch>
> > To: "kea-users" <kea-users at lists.isc.org>
> > Sent: Wednesday, November 16, 2022 11:27:07 AM
> > Subject: [Kea-users] How to best update the KEA configuration on a HA
> hot-standby KEA setup
>
> > Hi,
>
> > When running KEA on one single server, (no HA), and updating the KEA dhcp
> > configuration file every 5 minute, using "config-set"
> > [
> >
> https://kea.readthedocs.io/en/latest/arm/ctrl-channel.html?highlight=config-set#the-config-set-command
> > |
> >
> https://kea.readthedocs.io/en/latest/arm/ctrl-channel.html?highlight=config-set#the-config-set-command
> > ] ,
> > we can see that KEA does not reply to the DHCP requests during 30-35
> seconds
> > while "config-set" is running.
>
> > Is it expected ?
> > If yes, if we add a second server in a HA hot-standby mode, can we
> expect it to
> > answer to the DHCP requests while the first server is busy with
> config-set ?
> > If yes, we need to update the second server asynchronously with respect
> to the
> > first one, else they would both be busy with "config-set" at the same
> time.
>
> > I would be interested to know how people are updating the KEA DHCP
> configuration
> > in a HA hot-standby setup.
>
> > Thanks,
> > Veronique
>
> > --
> > ISC funds the development of this software with paid support
> subscriptions.
> > Contact us at https://www.isc.org/contact/ for more information.
>
> > To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>
> > Kea-users mailing list
> > Kea-users at lists.isc.org
> > https://lists.isc.org/mailman/listinfo/kea-users
> --
> ISC funds the development of this software with paid support
> subscriptions. Contact us at https://www.isc.org/contact/ for more
> information.
>
> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>
> Kea-users mailing list
> Kea-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/kea-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/kea-users/attachments/20221116/9aac1b97/attachment-0001.htm>