DNS change today

[mark]

Hi all,

We had a brief outage this morning. The cause was an (unexpected) policy change by our DNS provider, Dyn, deciding to shut us off. They had to roll back the change for unrelated reasons so we were back online, but it does mean that we need to migrate off of their service.

ETA: The policy change was that, for about 10 years now -- as long as I've been using Dyn! -- they had no usage/quota limits on their DNS service. Given that DNS requests are tiny and easy to serve, this made sense. They made a business decision recently to establish some (rather tiny) quotas. We're ... quite in excess of them (by some 15,000%) and we don't want to pay in excess of $500 USD/month for DNS service. Amazon's price is 10% of that. They probably tried to contact us, but I don't recall seeing any emails. Anyway, that's it; it's nothing particularly nefarious.

We will be moving our DNS service to Amazon's Route53 service. This kind of migration is fairly easy technically, but if there are problems it will probably mean Dreamwidth will be offline until they can be resolved. And, given the nature of how DNS works, it means that any outage will probably be measured in hours rather than minutes.

I've done my best to ensure that the changeover will go smoothly. If anything happens, though, we'll be on our dreamwidth account to keep everybody apprised of the progress.

The switch will be flipped around 3:30pm PDT / 2230 UTC today, this is in about 90 minutes.

Comments

[dil]

And why don't you run DNS on the same machines as web servers? What's the problem with it?

[mark]

I used to run my own DNS and for a while I think we even self-hosted Dreamwidth's DNS. The main advantage to not self-hosting though is that, if we lose our web server provider, we can do things like point the web site at a new IP so people can get a status page up. Also, in the unfortunate case of someone attacking the site (DDoS, etc) it's really nice to have the DNS service run on someone's very powerful hardware and very fat pipes -- ours certainly aren't that big.

A second useful thing about it is that folks like Amazon actually have a widely distributed DNS infrastructure. Every DNS request is going to take some time to complete, which adds to how long it takes the site to load for people. If we hosted DNS ourself then our users who aren't near Texas, USA will have extra latency. Amazon has servers all over the globe and this helps the site feel faster for people who aren't near us.

Also personally, it's well worth the $50 a month to have someone else worry about DNS infrastructure. They will actually do it much better than I could in the time I have available. (And I'd rather spend that time on DW itself!)

DNS

[babysprite]

Understood

If you don't have a robust set of resources, better to let someone who does provide the DNS.

Time to renew my paid subscription to help DW pay the bills.【ツ】

DNS costs DW fifty dollars a month, I can subscribe for fifty dollars a year.

Done.

[arethinn]

$50 a month for ~119 million DNS lookups? Wow, they're charging tiny fractions of a cent per each.

[mark]

Yup. 40 cents USD per million queries; it's pretty cheap. Realistically though, DNS is super cheap to serve. The expense/hard part is in hosting servers in dozens of regions to minimize latency, not the hardware cost itself.