Top > June 2011

6/21/11 by DW

This is where Dave Winer narrates his development work.

Continuing on Route 53

Going to try hooking it up behind an XML-RPC interface and see if it works.
It works -- but it's slow. I'm running the same test I ran for dnsimple.com.
The first test took 1119 seconds betw the time the call to AWS returned and the time a DNS lookup for the domain worked. (That's 18 minutes!)
Running another test.. (Took exactly the same amount of time.)
Heard back from Amazon, there's a value called "negative time to live" which determines how long a server caches a negative result. By default its value appears to be 18 minutes. Verified. If I make my test script wait ten seconds before making the first request, the DNS lookup works the first time.
So the moral of the story is we need to set a very short NTTL value. It's in the SOA record. Unfortunately Interstate 53 doesn't have an interactive way to set this.
I suspect the same problem is happening on dnsimple.com.
Suggestion from Amazon product manager: "If you want to be insulated from this after creating a new CNAME poll the GetChange API to find out when the change is actually available on all DNS servers. While we're usually good in 10-20 seconds but there are periods where we exceed that."
I added the synchronizer, and it's all good. :-)