Question Error 502/503 php 7.4

[Nicola]

Hello,
with php 7.3 I do not have any problem, when I upgraded to php 7.4 I get random errors like these:

php74-error.log
[10-Jan-2020 08:24:38] WARNING: [pool example.com] child 11839 exited on signal 11 (SIGSEGV) after 2.798999 seconds from start
[10-Jan-2020 08:24:38] NOTICE: [pool example.com] child 11860 started

proxy error log
[error] 14182#0: *141670 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: xx.xx.xx.xx, server: example.com, request: "GET /index.php?idpag=1719 HTTP/2.0", upstream: "fastcgi://unix:///var/www/vhosts/system/example.com/php-fpm.sock:", host: "example.com", referrer: "https://example.com/index.php?idpag=1"

audit log
type=ANOM_ABEND msg=audit(1578641078.835:1427547): auid=4294967295 uid=10038 gid=1003 ses=4294967295 pid=11839 comm="php-fpm" reason="memory violation" sig=11

messages log
Jan 10 08:24:38 ru000815 kernel: traps: php-fpm[11839] general protection ip:6f5fda sp:7ffd80b0b530 error:0 in php-fpm[400000+3fc000]

php is executed in "Application FPM served by nginx". Someone can tell me if there is a way to investigate further?

Thanks in advance

 

[unixpro]

Me too. Same issue.
Nginx returns a 502 (or 503 if using apache also).
I am trying to get a core dump so that I can use gdb to backtrace, but I think the plesk php-fpm is not compiled with --enable-debug.

Next things I am going to try is manually add script logging to that FPM pool to try and see what calls cause it.
Also I will try to exclude imagemagick module as that has caused similar issues in the past.

I will report back if I get anywhere.

 

[Bitpalast]

Are your using PHP 7.4 as delivered by Plesk or are you using your own compiled PHP with APCu? If so, can you try to turn APCu off? Because it is likely that this causes the crash.

 

[unixpro]

No APUu here, Imagick had no effect.
I didn't get a core dump either so I'm going to keep trying different settings and disabling modules till I track it down.