Hi Sander, Thanks for the reply. I was reading through the man page for keepalived.conf and noticed the 'nopreempt' option just after I sent the mail.
Cheers, Campbell On Thu, Jul 8, 2010 at 10:08 PM, Sander Klein <[email protected]> wrote: > Hi, > > On Thu, 8 Jul 2010 20:17:33 +0100, campbell mcleay > <[email protected]> wrote: >> I was interested in setting up LVS-NAT with keepalived for a redundant >> setup. All of the documentation recommends one director designated as >> master and one as backup. However, I was wondering if there is an >> issue having both as backup, the reasons for this configuration being >> 1) that config can be synced between the two directors, and 2) that if >> the master goes down and comes backup, it would not mean that the >> master would then take over again. I have read having the same >> priority could result in a race condition, but wouldn't this be very >> unlikely, since it would require both to come up at exactly the same >> time. I have not found any one else with such a setup, and all >> documentation says there has to be a master and backup with different >> priorities, so I want to be careful that I haven't missed something. >> It seems to work ok in practise so far though. > > This question might better be asked on the keepalived mailing list. Maybe > someone has a better answer there than I have now. > > I think you can give both directors the same priority. A director that is > in backup state and receives a vrrp packet with the same priority as it's > own should stay in backup state. But I can imagine it is possible that both > directors get in a state that they both start flapping between master and > backup state. I didn't look at any code, I only quickly reviewed the RFC. > So it might as well just work. > > About your second point. You could use the 'nopreempt' option in the > keepalived config to keep a director with a higher priority from becoming a > master. So, when the directors initially start the director with the > highest priority becomes master. The master fails, so the director with the > lower priority becomes master. When the director with the higher priority > comes back online again it will become a backup director and stays backup > until the director with the lower priority fails. > > Greets, > > Sander > > _______________________________________________ > Please read the documentation before posting - it's available at: > http://www.linuxvirtualserver.org/ > > LinuxVirtualServer.org mailing list - [email protected] > Send requests to [email protected] > or go to http://lists.graemef.net/mailman/listinfo/lvs-users > _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - [email protected] Send requests to [email protected] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
