A message comes in: a website is not responding.

[stefano@mastodon.bsd.cafe]

A message comes in: a website is not responding. Or rather, it responds but it crawls.
It is a WordPress with a few plugins, all in good shape.

I log in and the load is near zero, traffic is tiny. I start digging and nothing makes sense. I run the command "w" and the machine is frozen.

Nothing in the logs.
Then the light bulb goes on:
"ping bsd.cafe"

No resolution.

The provider’s upstream DNS servers (set in a hurry, I normally install a local unbound) are not responding and everything grinds to a halt. I switch the DNS servers and everything magically starts working again.

Of course it was DNS! 🙂

#IT #SysAdmin #DNS #SaturdayMorningEmergencies

[tionisla@mastodon.bsd.cafe]

@stefano DNS - it's in the DNA of the web 😉

[winfried@fosstodon.org]

@stefano if the system is so heavily dependent on the DNS resolver ("frozen"), I would dig deeper, as there could be much more to it

[stefano@mastodon.bsd.cafe]

@winfried the "w" command will, by default, try to resolve the ip addresses into hostnames - that's why it is slow if the resolver isn't responding properly.
As for Wordpress - many of the plugins they are currently using depend on external calls.

[pertho@mastodon.bsd.cafe]

@stefano "We need more pow ... DNS!!!!!" 😂

[subnetspider@mastodon.bsd.cafe]

@stefano "It's always DNS" - or rather, a lack there of ;)

[omar@mastodon.bsd.cafe]

> Of course it was DNS! 🙂

@nuintari just emptied a magazine out of the window, thanks @stefano , he scared all his neighbors.

[nuintari@mastodon.bsd.cafe]

@omar @stefano Cheap out on your DNS setup, pay the price later.

[stefano@mastodon.bsd.cafe]

@nuintari @omar totally agree