On Mon, Nov 18, 2019 at 12:06:08PM +0100, Baptiste wrote: > When we first designed this feature, we did it with this in mind "if admins > can update a SRV record in a DNS server, they can adjust the weight > accordingly". > > I understand the need, but the response is way too short. It's a global > question of precedence in HAProxy from my point of view. > I am scared that if we start to adjust things this way, we'll end up with > 1000s of flags overlapping each others and adding complexity on top of > complexity. > > The real question is "what prevents an admin from updating a DNS record?" > Or why they don't failover to A/AAAA records only?
I must admit I understand a valid use case : have the DNS set up to advertise the list of servers, and let the agent adjust the servers' health based on their load, the fact that they're running backup or OS updates etc. Thus in my opinion, the *use case* makes sense. What I'm unsure about is the proper way to do it, because as you mention, it's more a matter of overall consistency between all sources. We could very well instead have a per-backend setting indicating what source to fetch the weight from (agent, dns, health, other?), where to fetch the maxconn from etc. Some may even want to combine these (average, multiply, ...). I'm fine if you prefer to postpone it. If in the end we decide to merge it as-is we could also backport it, and if we decide to address it differently, at least we won't have to maintain one extra short-lived flag. Thanks, Willy
