/plushcap/analysis/cloudflare/debugging-war-story-the-mystery-of-nxdomain

Debugging war story: the mystery of NXDOMAIN

What's this blog post about?

The blog post describes a debugging adventure on Cloudflare's Mesos-based cluster, which is primarily used to process log file information and detect attacks. Engineers encountered an issue where internal DNS queries were returning "no such host" errors for existing domains. Through extensive testing and analysis, it was discovered that the problem stemmed from packet loss during DNS resolution attempts. The solution involved increasing the retries option in the resolv.conf file to better handle transient network issues and improve the reliability of DNS resolution.

Company
Cloudflare

Date published
Dec. 7, 2016

Author(s)
Ivan Babrou

Word count
1621

Hacker News points
None found.

Language
English


By Matt Makai. 2021-2024.