503 Service Unavailable or Empty Response on specific pages over PHP (PHP-FPM) on MacOS

Question

I've got a strange problem here involving some versions of PHP installed in my local machine (MacOS Ventura 13.5).

Certain pages (two at this moment) doesn't load in some versions of PHP. It's loads ok in [email protected] but doesn't load in [email protected], [email protected] and [email protected]. Detail: these pages are compatible with any php version and works on Windows and Linux over [email protected], for example.

I can't debug this error (or i don't know how can i do that).

dmesg show me only this:

[ 3074.896856]: Waking up reference: 1001 Thread waiting on reference 1001 woke up evaluation result: 1001, allowed, skip-cache, 0 Waking up reference: 1002 Thread waiting on reference 1002 woke up evaluation result: 1002, allowed, skip-cache, 0 Waking up reference: 1003 Thread waiting on reference 1003 woke up evaluation result: 1003, allowed, skip-cache, 0 php-fpm[10627] Corpse allowed 1 of 5 

Apache log or php-fpm log show me something like this:

WARNING: [pool www] child 10627 exited on signal 11 (SIGSEGV) after 632.773071 seconds from start

More info:

• Without php-fpm: same problems.
• Tried to change some options in php-fpm.conf, no success.
• I think it's related with some php extension not compiled very well, maybe?

Answer 1

It sounds like PHP is crashing on those pages. To reolve this you need to enable core dumps, analyze the dumps with a debugger to identify the cause, re-write the relevant parts of PHP or the extension, recompile and re-deploy. That's not very practical for most people.

Clearly, these pages are NOT compatible with any version of PHP.

some php extension not compiled very well

No, it's most likely a bug in the code somewhere. Any dependency issues would be flagged in the error logs when you restart PHP-FPM.

You do however appear to have a reprocible test case, so it should be trivial to instrument that with detailled logging to isolate where it is crashing.