Just to add my 2 cents to this thread. I am currently working on a 3-host galera MySQL cluster along with 2 kea servers that will handle my DHCP failover seemlessly. Built on Debian Stretch, the last piece I am writing is a migration script to take the lease4.csv file and import it into mysql.
On Wed, Nov 22, 2017 at 8:34 AM, Hugh Connolly <[email protected]> wrote: > I'm working on something similar. > > > It uses 2+ Kea instances with the postgresql lease db in Amazons RDS. > > To manage the VIP the cluster uses ocf_heartbeat_IPaddr2 (pacemaker) > > > Works quite well thus far. > > > What do you think? > > > One improvement (beyond in-housing the Postgresql cluster) that comes to > mind is better fencing in PCS to restart the service or shutdown the node > if there is a problem. Something beyond just checking that the service is > running, maybe checking the ports? > > > Was fairly straight forward to setup > ------------------------------ > *From:* Kea-users <[email protected]> on behalf of Klaus > Steden <[email protected]> > *Sent:* Friday, November 17, 2017 4:14:00 PM > *To:* SoupNazi izaNpuoS > *Cc:* KEA-Users ([email protected]) > *Subject:* Re: [Kea-users] DHCP redundancy > > > Our implementation uses a single database backend (which is itself HA, but > the endpoint is a VIP, so it appears to be just a single host) with a > different server per environment running a Kea server. It seems they > coexist quite happily as long as they're not trying to both handle the same > row/table, which means each environment only uses a single IP helper. > > We use Monit on the servers themselves to keep the Kea daemon running, > since as noted it doesn't retry when it encounters an error talking to the > database; the whole system is generally fairly resilient, FWIW, even if > it's less than industrial strength. > > cheers, > Klaus > > On Fri, Nov 17, 2017 at 6:48 AM, SoupNazi izaNpuoS <[email protected]> > wrote: > > Not at all. It does split the pools, automatically. You just need to > make sure you don't use more than 90% of your addresses as it may have > difficulty transferring IPs amongst the devices if you do (say if the > secondary runs out, the primary may not be able to send IPs to it). > > On Fri, Nov 17, 2017 at 9:44 AM, John Ratliff <[email protected]> wrote: > > On 11/17/2017 9:37 AM, SoupNazi izaNpuoS wrote: > > Out of curiosity, was there a reason you didn't use the built in failover > configuration in ISC DHCP? > > > It's extremely confusing to me. Perhaps my understanding is flawed, but as > I understand it, you need to split your pool and have one side responsible > for their individual split. Our pools do not have enough spare IPs to allow > that. It just never seemed work the effort. > > --John > > > On Fri, Nov 17, 2017 at 9:25 AM, John Ratliff <[email protected] > <mailto:[email protected]>> wrote: > > I'm seeking best practice advice on how to setup DHCP server > redundancy with kea. > > With ISC DHCP, I used VRRP with two servers and configured it to > send the dhcp-server-identifier option as the VRRP IP. Then I would > run a script that sync'd the lease database automatically via cron. > > This process is messy and error prone, so I would like to use kea > instead. > > The subnets I am allocating via DHCP is not the same subnet that the > server is in, so we use ip-helper statements to forward DHCP > requests to the server. > > I have kea using mySQL as a lease backend. The mySQL server is not > on the same machine as kea. > > My first thought was to use VRRP and supply the > dhcp-server-identifier option again. I ran into a problem though > that if kea started before VRRP, it wouldn't listen on the VRRP IP. > There is probably a solution to that, but I don't have one yet. > > So then I changed the router configuration to use two ip-helper > statements, sending the request to both primary and secondary kea > servers; I also removed the dhcp-server-identifier option. This > seems to work. > > Is this a reasonable setup for DHCP redundancy with kea? Is there a > better option I might want to consider? Are there any concerns I > should be aware of with both servers being active? > > Thanks. > _______________________________________________ > Kea-users mailing list > [email protected] <mailto:[email protected]> > https://lists.isc.org/mailman/listinfo/kea-users > <https://lists.isc.org/mailman/listinfo/kea-users> > > > > > > _______________________________________________ > Kea-users mailing list > [email protected] > https://lists.isc.org/mailman/listinfo/kea-users > > > > _______________________________________________ > Kea-users mailing list > [email protected] > https://lists.isc.org/mailman/listinfo/kea-users > > -- Munroe Sollog Senior Network Engineer [email protected]
_______________________________________________ Kea-users mailing list [email protected] https://lists.isc.org/mailman/listinfo/kea-users
