Regular short getaddrinfo EAI_AGAIN outages

[nebulon]

unbound is still used in Cloudron, but its usage is drastically reduced now. It is used for directly querying the nameservers to check if DNS records are already in-sync to avoid hitting NXDOMAIN for newly installed apps as well as for email DNS record lookup.

The rest now uses whatever the default setup, of the environment the server is running in, is.

[girish]

To conclude what @nebulon said, for Uptime Kuma this means that it uses the system DNS (and not unbound).

[factord]

@girish ouch, i still have the EAI_AGAIN error, i suppose i have to check with uptime kuma then. Any suggestion? maybe our datacenter dns is overloaded and we should use google dns or something like that?

[girish]

@factord right, so this means this is either a local DNS issue or uptime kuma issue. Quick idea is to just set up the server's /etc/resolv.conf with Google DNS maybe and check if it mitigates the issue.

[thoresson]

I've used Uptime Kuna without any problem since April. But for the last 24+ hours I suddenly have started to receive tons of these:

The affected hosts are on .se, and one .social. Some of them are hosted at the same box I run Cloudron on, some on others.

I see that it's not the same error message as in the OP, but similar enough to be related?

According to my logs, my Cloudron was updated to 8.0.4 on August 28, and 8.0.6 yesterday morning. I don't know for sure, but from the graphs it looks like the problem started as soon as that update had been installed. This is what the week graph looks like for or the monitored services with problems:

[joseph]

@thoresson usually, ENOTFOUND is a problem with the DNS. Is the DNS working on the server? You can try host www.cloudron.io from the host (via ssh) and also viw the Web Terminal of the Uptime Kuma app. Do they work?

[thoresson]

@joseph Yes, this is what I get using the web terminal.

But could it be that the DNS is going down intermittently?

[joseph]

@thoresson which version of Cloudron are you on? Can you upgrade to Cloudron 8.0.6 ? Starting 8.0.6, all app containers also use the system DNS. You can find out your DNS servers using resolvectl on the server.

[thoresson]

I'm on 8.0.6 since Tuesday morning, which incidentally also is when those problem started.

Should I use resolvectl from Uptime Kuma's web terminal?

[joseph]

@thoresson you should use it via SSH

[thoresson]

Netcup's DNS servers are configured for my Cloudron instance.