Hi there:
If you or your subscribers have been frustrated trying to get to a FeedBlitz feed (or click through to a link in a feedblitz feed) in the last 24 hours or so, the reason is because some third party DNS servers have been returning the wrong results for feeds.feedblitz.com. The net effect is that although FeedBlitz is up and your feeds are being served, some subscribers are being sent to the wrong servers, and getting errors as a result.
Here's the explanation.
DNS, or the Domain Name System, is the thing that translates web host names, like feeds.feedblitz.com, to machine IP addresses, such as 198.251.67.124, which allows the traffic to get between your computer and the correct server.
Yesterday morning, some DNS services, (notably Google’s public DNS server, which is used by many people, services and organizations), started to return not only inconsistent results, but demonstrably incorrect results. In short, they redirected traffic to the wrong servers for much of the day.
Now here at FeedBlitz we have an enterprise DNS provider. Misrouting traffic is clearly a major issue and we woke people up yesterday morning to try to (a) correct the situation, and (b) determine what went wrong. As far as we can tell, our authoritative DNS entries were all fine, but thanks to DNS caching and inconsistent results being returned for much of the day yesterday by Google’s servers, traffic for feeds for some people and services ended up in the wrong place, at a server not expecting nor designed to handle feeds traffic, returning errors.
Despite our best efforts, we couldn’t get Google to return consistent and correct DNS results globally until yesterday afternoon, US eastern. At that point, new DNS lookups for feeds.feedblitz.com will have been successfully sent to the correct servers.
The problem is, however, that DNS lookups are cached – stored temporarily – by the machine making the DNS request. So while Google’s DNS finally got its act together yesterday afternoon, all the queries that were bungled before that were - and are - being cached by the machines that requested them. Those caches are held for a duration known as the TTL – time to live – time. That time may be many hours, and so requests being made to feeds.feedblitz.com now may still being routed to the wrong server, because of incorrect data cached yesterday, if the machine in question, or its upstream DNS provider, got that incorrect data.
We know this is incredibly frustrating for everyone affected, but the cause appears to be downstream from our DNS provider. Our DNS records are correct. As far as we can tell, all major DNS providers are returning the correct results now too. That’s the good news.
While we’re trying to figure out what happened, unfortunately we can’t control downstream DNS caches and third party DNS providers. The ugly truth is, if you’re having problems, unless you’re running your own DNS architecture which you can refresh, all you can do is hang around for your DNS cache's TTL to expire for the feeds.feedblitz.com record; in other words, hurry up and wait. That stinks, I know.
Still, if you’re on windows, you can run this command from a command prompt to see if you're affected:
nslookup feeds.feedblitz.com
As I write, you should get four IP addresses back. If you do, all is well. If not, you have stale and incorrect DNS data. On windows, you can clear your local DNS caches with this command:
ipconfig /flushdns
If you now re-run the nslookup command from further up, you might get the correct results. If not, that means a DNS cache upstream from you is stale and has the incorrect data. At this point, unless you control that upstream DNS server and can fix it, you have to wait for that DNS cache to expire and the correct DNS data to be served.
We here have done all we can to diagnose and address this issue. Our DNS records are correct and are being correctly and consistently returned by downstream servers.
I understand and appreciate the frustration. I hope this helps explain what’s gone on and how little we can control it.
Thanks,
Phil
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