Hi

I'm looking for a bit of advice on configuring PHP-FPM/DB connections/Wordpress... I'm not sure where the problem is which is why it's a vague question.

Essentially, our Woocommerce site struggles when there's more than a single visitor. If I have a page open then middle-click a few links to open in background tabs, they resolve one after the other and their TTFBs increase 2 seconds per page load. It's almost like there's a single process sequentially responsible for every site visitor so it's very easy to get TTFB of 20 seconds with just a couple of visitors opening a few pages.

I've never used PHP-FPM before so I'm not sure what to set it at. I've had it at the default (Requests = 20, Max Child Threads = 5), I've increased child threads to 20, there didn't seem to be a difference.

I've checked the max connections in Maria and it's at 250 so... that shouldn't be an issue?

I've tried running WP with no plugins and the difference to TTFB was barely noticeable.

Running cURL against a basic phpinfo page still gives a 2 second TTFB which is what makes me think it's some kind of single process or slow process start issue.

Requesting a static CSS or HTML file gives a TTFB of <40ms which, again, points me at PHP.

I'd link the site here but, as I've said, if anyone besides me visits it, it becomes unusable.

Any advice? I'm guessing this isn't normal. I'll follow up with support but just asking here incase anyone has faced the same and has a configuration suggestion.