NXDOMAIN Issue
Why the spike in NXDOMAIN responses, recently faced with a huge downtime where chrome shows: DNS_PROBE_FINISHED_NXDOMAIN when my site is being visited. Even now cloudflare shows spikes in NXDOMAIN responses occasionally
3 Replies
Should I worry?
Mouse over NXDomain, click Filter, swap over to Query Name and see what's nxdomaining
Those new analytics are as powerful as Pro's http analytics. You can filter and comb through the data with a lot of flexiblity. See if it makes sense what's NXDomaining (random domains you don't use, a type that doesn't exist on there, see the Src IPs, etc)
Checked out NXDOMAIN by filtering and zooming it in... all of those subdomains don't even exist in records so yeah they're useless...
But I need to share an incident that occured on 7th Oct around 9.50 am IST... All our valid domains / A records which have been working perfectly fine for over a year, suddenly all of those valid domains have shown "DNS_PROBE_FINISHED_NXDOMAIN" on that day and the issue lasted for around 6 hrs approx before automatically fixing by itself... I suspect this as an issue with Cloudflare DNS... I've complained to our hosting service - AWS - but it wasn't the case, cause all the hosted instances were up and running and were accessible over instance public IP.
But they were inaccessible through domain names - which caused me to reboot instances on ec2 in panic - which inturn changed IPs of some instances and I'd to make an A record update for the modified IPs and Subdomains causing downtime and propogation delays.
AWS support suggested that the service disruption was cloudflare, but I don't really understand why only I was affected