121–130 of 229 posts
https://downdetector.com/archive So many sites down... and unfortunately not one of them is Twitter
Basically soft-invalidate your local DNS cache but it back from the cache graveyard if DNS is down.
Earlier quoted context omitted.
Depending on what point you draw the line of "single point of failure" you could use multiple providers for your dns. GOV.UK for example uses both aws and gcp for DNS
So, NS entries pointing to both? But then take the example your domain was in Route53 and AWS goes down. You can't configure the NS entries to avoid AWS DNS servers. Is the idea that child DNS servers detect the outage and cache the values in the name server(s) that remain up? But then, the cached values from AWS take a while to clear, TTL never seems to be applied properly. It always feels like the worst case in suc…
https://github.com/octodns/octodns
DNS is fastest first* rather than main/failover. If AWS DNS was down your GCP DNS would have replied (if all is well) sooner than {timeout} so your visitor would still have a response
* Sort of. I think if the client doesn't get a reply from the server it picked randomly in 1s they move on to the next server, repeat until all fail
What role does Akamai Edge DNS play in normal internet traffic? DNS responses usually get cached, as far as I understand correctly. And it is usually possible to change your DNS server to e.g. Google's and circumvent the outage. Does Akamai Edge DNS play a role on the server side?
The trend these days are DNS TTLs of 60 - 300 seconds, to allow "Cloud agility" or something, so sites are exposed to a much larger risk of authoritative nameservers going down.
Services like Akamai use short TTLs for their edge services for a variety of reasons, not least because if one of their edge servers goes offline (for planned or unplanned reasons) it lets them sub in a new one and have it receive traffic immediately, rather than have a bunch of clients continue trying to talk to a dead node. So sure, you can increase those TTLs to trade 'what if the DNS server goes down?' risk with 'what if the edge server goes down?' risk...
But keeping the edge servers up and running is probably a lot harder - they need to scale more to handle traffic load, they have to actually handle client data, TLS termination, much more complex configuration.... so if I'm placing bets on which of those things is more likely to die on me, it's the edge node, not the DNS server.
https://downdetector.com/archive So many sites down... and unfortunately not one of them is Twitter
Is there a way to tell your system to fall back to the last known IP address if DNS server isn't reachable? Basically soft-invalidate your local DNS cache but it back from the cache graveyard if DNS is down.
https://downdetector.com/archive So many sites down... and unfortunately not one of them is Twitter
Is there a way to tell your system to fall back to the last known IP address if DNS server isn't reachable? Basically soft-invalidate your local DNS cache but it back from the cache graveyard if DNS is down.
Absolutely amazing how many billion $+ companies are single homed for DNS. I wonder how much they spend on multi-AZ redundant architectures...
Whatever multi-home means, why can't there just be one service provider that does that? And are we sure that these service providers aren't already doing that as best we might hope for? (For instance, Amazon already has multiple zones, etc.)
I suppose the one thing this can't protect against is some sort of political (broadly defined) threat related to the company itself.
https://downdetector.com/archive So many sites down... and unfortunately not one of them is Twitter
Please keep comments like this off HN