Issue Segfault error 4 in php-fpm likely on CPU 4

[AlexReiner]

Server operating system version

Debian 12.5

Plesk version and microupdate number

18.0.61 #1

Hi!

We are currently want to migrate to a new Debian 12 server with Plesk. We are getting random 503-Errors. If we look into "dmesg" we are getting following error:

php-fpm[2446]: segfault at 9 ip 0000562ca644a6ce sp 00007ffd0cc4bf30 error 4 in php-fpm[562ca6188000+3b5000] likely on CPU 4 (core 4, socket 0)

We've tested on two different servers with Debian 12 - same error..
And the PHP-Version doesn't matter.


The servers are running on a proxmox host. On the same server are different webservers (without Plesk) and they don't have this issues...

Can someone please help or know what to do?

Thank you!

 

[Avox]

I have the same error, on Debian 11 and 12 with the Hetzner Plesk setup.

See last Post here:

Issue - php-cgi segfault

Hi, Our plesk server with 64GB ram and Intel(R) Xeon(R) CPU D-1520 with 4 core is showing very poor performance. We are running around 100 live websites in the server. We have done server tweaking for maximum performance. We are experiencing slowness with websites in the server. We...

talk.plesk.com

 

[AlexReiner]

Also wir nutzen auch Hetzner - den EX101

 

[Avox]

Also troubles Debian with Plesk php-fpm8.1: segfault at ... ip ... sp ... error 4 in opcache.so · Issue #8149 · php/php-src

 

[Avox]

It looks like Plesk has problems with Debian 11 and 12 with FPM PHP?
Currently there are no problems on Debian 11 or 12 without Plesk or Plesk with Ubuntu 20.04.6 LTS or 22.04.4 LTS has no problems about my network.

 

[AlexReiner]

Also troubles Debian with Plesk php-fpm8.1: segfault at ... ip ... sp ... error 4 in opcache.so · Issue #8149 · php/php-src

This problem is with opcache. If you disable opcache the same error occours....already tested

 

[ChristophRo]

Our Debian 10, 11 and 12 servers do not show any problems with PHP and they are all on 18.0.61#1

Maybe an extension you have loaded and we don't? (we use the default set of plesk)

 

[AlexReiner]

Initial installation - no changes

 

[Avox]

We are talking about new installations, but are you sure that you have no problems with D11 & D12 @ChristophRo?
The problem mostly happens after multiple page views, maybe you can check your logs in /var/log/syslog for a php fpm segfault error?

 

[ChristophRo]

already did that, checked syslog on multiple servers (with several thousand websites on it) and so far zero/zilch segfaults

on what PHP versions does this happen for you? (we do use deb.sury.org for some, as to have older versions and also longer maintained ones, than from Plesk)

 

[Avox]

For me it was on PHP versions 7.4, 8.0, 8.1, 8.2

 

[AlexReiner]

For me 8.0, 8.1, 8.2 and 8.3

 

[ChristophRo]

if not for PHP 7.4, I would have suspected that maybe the JiT compiler has some say in this...

 

[AlexReiner]

Hmmm good idea let me test

 

[AlexReiner]

Hmm I've tested and the last 15 minutes no error...
I set
opcache.jit=0

 

[AlexReiner]

Hmm I've tested and the last 15 minutes no error...
I set
opcache.jit=0

Happened again....

 

[AlexReiner]

 

[Avox]

@ChristophRo you host bei Hetzner?
Maybe we have only Troubles by an Hetzner Server?

 

[ChristophRo]

Nope, we run our own physical servers and virtual infrastructures

Does the problem also happen when using the "OS" PHP version with Plesk? That would eliminate a possible influence of the php compiling process that Plesk uses for it's own shipped versions.

 

[AlexReiner]

Same problem...(only tested php8.3)

One of our productive server (CPX41) running Debian 11 since 2 years now (I think) - never had problem with it but there are also segfaults - we name it 1


another CPX41 don't have any segfaults.. - we name it 2

Expand/Collapse Block: Specifications CPX41

Memory: 16 GB

Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
Address sizes: 40 bits physical, 48 bits virtual
CPU(s): 8
On-line CPU(s) list: 0-7
Thread(s) per core: 1
Core(s) per socket: 8
Socket(s): 1
NUMA node(s): 1
Vendor ID: AuthenticAMD
CPU family: 23
Model: 49
Model name: AMD EPYC Processor
Stepping: 0
CPU MHz: 2445.406
BogoMIPS: 4890.81
Hypervisor vendor: KVM
Virtualization type: full
L1d cache: 256 KiB
L1i cache: 256 KiB
L2 cache: 4 MiB
L3 cache: 32 MiB
NUMA node0 CPU(s): 0-7
Vulnerability Itlb multihit: Not affected
Vulnerability L1tf: Not affected
Vulnerability Mds: Not affected
Vulnerability Meltdown: Not affected
Vulnerability Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl and seccomp
Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Vulnerability Spectre v2: Mitigation; Retpolines, IBPB conditional, IBRS_FW, STIBP disabled, RSB filling
Vulnerability Srbds: Not affected
Vulnerability Tsx async abort: Not affected
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm rep_good nopl cpuid extd_apicid tsc_known_freq pni pclmu lqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm cmp_legacy cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw topoext perfctr_core ssbd ibrs ibpb stib p vmmcall fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves clzero xsaveerptr wbnoinvd arat umip rdpid arch_capabilities

The difference between these two servers are:
Server 1 - PHP > 8.1
Server 2 - PHP 8.0, one website on PHP 8.1

Currently testing:
Installed PHP8.0 via Plesk Installer and changed the problematic sites to 8.0 . Until now (last 30 minutes) NO segfaults!