Hi Baptiste, > What this means is that backup status would use priority 0 or 1 or some kind > of. But we burn the remaining 65534 values from this field.
That's a concern, for sure. > I also think we wanted to have "server groups" first in HAProxy before using > the priority. The idea before server groups is that a bunch of server should > be used all together until they fail (or enough have failed), and in such > case, we want to fail over to the next group, and so on (unless first group > recovers, of course). This would be amazing for us! We're struggling with occasionally having all servers "up" in a pool (but struggling), and requests not getting moved to the next (backup) pool when they fail. Having groups we could use to control failover more closely would be really nice for us. SRV records, or not. :) > What we can do for now, is consider "active" a priority 0 and backup, any > value greater than 0. I think that's perfectly acceptable for us. I'm not sure of anyone else on the mailing list using SRV records, so I don't know who else we could ask about that. Would I have all I need to begin a patch for this in src/dns.c or will it require bringing in more pieces to accomplish the task? If it's going to be involved, a few pointers before I dive in would be helpful. My C is rusty (using mostly Rust now, anyways ;-) ), and my knowledge of the HAProxy codebase is weak right now. Best, Luke — Luke Seelenbinder Stadia Maps | Founder stadiamaps.com > On 28 Feb 2020, at 09:44, Baptiste <[email protected]> wrote: > >> I suspect that it's more a property of the resolvers than the servers. >> I mean, if you know that you're using your DNS servers this way, this >> should really have the same meaning for all servers. So you shouldn't >> have a per-server option to adjust this behavior but a per-resolvers >> section. > > That's even better! And probably more easily implemented. I'll wait for > Baptiste's response. > > Hi There, > > When we first designed support for SRV record, we thought about use cases for > this "priority" field. > That said, at that time, the conclusion was some kind of "it is not possible > to match a 'backup' state with an integer, or it is a "waste" of information". > What this means is that backup status would use priority 0 or 1 or some kind > of. But we burn the remaining 65534 values from this field. > I also think we wanted to have "server groups" first in HAProxy before using > the priority. The idea before server groups is that a bunch of server should > be used all together until they fail (or enough have failed), and in such > case, we want to fail over to the next group, and so on (unless first group > recovers, of course). Then, priority could be used to set up the groups, > cause HAProxy would assign al server with same priority in the same group. > > What we can do for now, is consider "active" a priority 0 and backup, any > value greater than 0. > > Baptiste
