ScorpioTiger

I've done some more troubleshooting and the problems goes away if I disable opcache in php.ini. So it would appear that something is failing in a less than graceful way. I'll start testing increasing memory for opcache and see what difference it makes. To anyone else seeing this strange behaviour whereby a page loads successfully the first time, but not subsequent times, try disabling opcache and see if the problem goes way; if so, you know where to look.

I did have the thought of recursion. The error response from the server is almost immediate, and it doesn't explain why identical requests can succeed the first time and fail the second.

I'm suddenly getting 500 server errors on a WordPress site. In the logs I'm getting; PHP message: PHP Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 68262447988 bytes) in /var/www/mysite.com/wp-includes/load.php on line 1357 That's 68 Gig that it's trying to allocate. Clearly this is a spurious message as nothing on the site is doing anything that requires anything like this much memory. I can restart PHP and load the page fine. When I try to refresh the page to load a second time, I get the error. It's the same regardless of the page I request. Always works first time, fails subsequent times. What could be causing this?