A slow website is usually nothing to do with the server itself but far more often to do with the code for the website itself. Have you used Chrome web vitals?
I like GT Metrix to test site load speed/issues. Not often specific enough but a good starting point to show how long it is taking and pretty explanatory.
Yes, I can install and configure plugins for cache and CDN purposes, but first of all why is server response time so bad? This was not the case earlier… why is it now? What has gone wrong since the OS upgrade? What virtualmin is unable to handle or what have I configured wrong?
Virtualmin isn’t involved in the web request path (there’s a web server, Apache or nginx, doing that job, probably proxying to a PHP app server). So, any Virtualmin upgrades would be unrelated to website performance. (But, web server or PHP/Python/Node/Ruby/whatever upgrades might, theoretically.)
We don’t have enough information to guess about the cause. You’ll need to narrow it down some.
Are all of the sites running the same app, just with different data? That’ll help decide where to look next.
There may be clues in the logs (error_logs for the domains, database logs, extra PHP logs, depending on execution mode, etc.). If you’re seeing internal connections timing out or being rejected for crossing a limit, for instance, that’d be a useful clue about bottlenecks (not necessary a smoking gun, but it at least gets you facing the right direction in the stack).
Some basic guidelines for performance issues: It’s almost never the web server (web servers are so fast on modern hardware, even without significant tuning, that no app stack can saturate them), it’s almost always some combination of app+database interaction. It could be DNS (because DNS is so often misconfigured, and DNS does weird things to most services when it’s misbehaving, including weird performance issues).
The first link: https://accountswise.co.uk/ is a pretty small website and written in core PHP, so that is not my main problem, but even this website has taken a hit.
But when I tried testing https://igocompliance.com/ which again is a very small and lightweight website but running on WordPress, using UK as a location, the output is not looking good:
What bothers me more is the fact that the same website when run on Lightsail in AWS with bare minimum spec has got a much better performance, which means website development/configuration might not be the core issue here. There is something misconfigured at the server level, which is slowing down the website rendering.
You’ve gotta look at logs. And, you need to start narrowing down the possibilities. A couple days in, all we still know is “it’s slow”, and have no idea what’s making it slow. Those websites that analyze performance can only tell you what you already know (it’s slow). You have access to information those sites don’t have (logs, top, etc.).
Second site on WP and using Element as a builder not going to help. I use brick builder and the facebook group are always bringing says Bricks Builder is alot faster to load then Elementor built sites. I’ve never used Elementor so I’m just going on what I hear.
Apart from that, I notice the CPU at 27%, is that steady at that level? Mine is 3 or 4% most of the time unless I’m running something like moving around webmin or doing a backup.
how many cores?
is it really steady? (in the dashboard what are the CPU load averages like?)
If even a “basic” php site is slow then what is that site’s php log like?
What happens if you have no site and just have the “Domain default page” loaded?
if even that is slow then I think you can rule out the webserver.
You don’t have clam antivirus running?
(with those WP sites running you could be attracting a whole load of spam mail)
If it is a dedicated server then I would worry and check which processes are intensively using the CPUs. If it is a VDS/VPS then I would discuss with the service provider to pay attention to how the hardware resources are used by the other clients. If it is not resolved, I would quickly change the service provider. A small DoS attack can claim the resources as well. so the problem must be analyzed both from the outside and from the inside. There are many factors that contribute to a website that is more difficult to load.
