Last update: Wed, Jul 1, 2015 at 7:12 PM.

6/21/11 by DW

    • 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. :-)