nanog mailing list archives
Re: Facebook post-mortems...
From: Bjørn Mork <bjorn () mork no>
Date: Wed, 06 Oct 2021 12:04:24 +0200
Masataka Ohta <mohta () necom830 hpcl titech ac jp> writes:
Bjørn Mork wrote:Removing all DNS servers at the same time is never a good idea, even in the situation where you believe they are all failing.As I wrote: : That facebook use very short expiration period for zone : data is a separate issue. that is a separate issue.
Sorry, I don't understand what you're getting at. The TTL is not an issue. An infinite TTL won't save you if all authoritative servers are unreachable. It will just make things worse in almost every other error scenario. The only solution to the problem of unreachable authoritative DNS servers is: Don't do that.
This is a very hard problem to solve.If that is their policy, it is just a policy to enforce and not a problem to solve.
The policy is there to solve a real problem. Serving stale data from a single disconnected anycast site is a problem. A disconnected site is unmanaged and must make autonomous decisions. That pre-programmed decision is "just policy". Should you withdraw the DNS routes or not? Serve stale or risk meltdown? I still don't think there is an easy and obviously correct answer. But they do of course need to add a safety net or two if they continue with the "meltdown" policy. Bjørn
Current thread:
- Re: Better description of what happened, (continued)
- Re: Better description of what happened Andy Brezinsky (Oct 05)
- Re: Better description of what happened Michael Thomas (Oct 05)
- Re: Better description of what happened Hugo Slabbert (Oct 05)
- Re: Better description of what happened Tom Beecher (Oct 06)
- Re: Better description of what happened Bjørn Mork (Oct 06)
- Re: Better description of what happened Tom Beecher (Oct 06)
- Re: Better description of what happened Hugo Slabbert (Oct 06)
- Re: Facebook post-mortems... Masataka Ohta (Oct 05)
- Re: Facebook post-mortems... Bjørn Mork (Oct 05)
- Re: Facebook post-mortems... Masataka Ohta (Oct 06)
- Re: Facebook post-mortems... Bjørn Mork (Oct 06)
- DNS pulling BGP routes? Michael Thomas (Oct 06)
- Re: DNS pulling BGP routes? J. Hellenthal via NANOG (Oct 06)
- Re: DNS pulling BGP routes? Jared Mauch (Oct 06)
- Re: DNS pulling BGP routes? Blake Dunlap (Oct 06)
- Re: DNS pulling BGP routes? Masataka Ohta (Oct 06)
- Re: DNS pulling BGP routes? William Herrin (Oct 07)
- Re: DNS pulling BGP routes? Masataka Ohta (Oct 07)
- Re: DNS pulling BGP routes? Tom Beecher (Oct 07)
- Re: DNS pulling BGP routes? Bjørn Mork (Oct 07)
- Re: DNS pulling BGP routes? Masataka Ohta (Oct 07)