Painfully slow-loading Dashboards

[Steini]

SYSTEM INFORMATION
OS type and version	Ubuntu Linux 24.04.1
Usermin version	2.102
Virtualmin version	7.30.3 Pro
Theme version	21.20.7
Apache version	2.4.62
Package updates	2 package updates are available

I installed Virtualmin on a test system and ran into a painfully slow-loading dashboard in both Webmin and Virtualmin views.

After messing about with the settings, I switched the HTTP protocol from HTTP/1.1 to HTTP/2 (un)encrypted for both the default and test server (under Webmin > Servers > Apache Webserver). Sure enough, the dashboards loaded at normal speed, and the slowdown with *min disappeared.

I also cleared the Authentic Theme’s cache.

I managed to reproduce the slow dashboard by switching the protocol back to HTTP/1.1.

Funnily enough, I’ve never had this issue on my production server – I reckon it’s because I enabled HTTP/2 from the start.

Not sure if this is directly related, but I thought I’d share in case it helps spot a bug:

Webmin 1.790 brings very slow dashboard refresh

Webmin/virtualmin panel loads slowly

Hello everyone, I wanted to know if the Webmin/Virtualmin panel is slow to load, I mean several sections, none load in less than 15 seconds, some take more than 30 seconds, when I add an account it takes 90 to 120 to create seconds, I have tried it with several systems. Take advantage of the blackfriday offers and buy a VPS/Cloud on Colohouse (they bought from Turnkey Internet this year and they offer the same plans), I think maybe the server is oversold, that’s why the panel is slow? SERVER/V…

[Joe]

@Steini

After messing about with the settings, I switched the HTTP protocol from HTTP/1.1 to HTTP/2 (un)encrypted for both the default and test server (under Webmin > Servers > Apache Webserver). Sure enough, the dashboards loaded at normal speed, and the slowdown with *min disappeared.

So…um…Webmin does not run under Apache. Nothing in Webmin can ever be effected by anything in Apache, unless you have configured Apache to proxy for Webmin. But, in that case, since Webmin’s web server does not support HTTP/2, enabling HTTP/2 in Apache still can’t make any difference in the behavior of Webmin.

I don’t know what changed or why it was slow before, but it certainly had nothing to do with Apache configuration.

[Steini]

Switching to HTTP/2 was the only option that made the dashboards load fast. Maybe a coincidence? Will keep an eye on it.

[Joe]

You can literally stop Apache and still use Webmin. Apache is not the web server for Webmin.

So, whatever the cause, it cannot be Apache configuration.

[Steini]

@Steini

I also cleared the Authentic Theme’s cache.

Rather than doing two steps to reproduce, I should have done one and see if it has an impact. I always cleared the cache after changing the setting.

I can confirm that without clearing the cache, switching back and forth from HTTP/1.1 has no effect.

Clearing the cache helps but only is a temporary workaround.