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Resolved 500 - Internal Server Error

Khorne

New Pleskian
Hi,

I cannot connect anymore to my Plesk panel, version 10.4.

I get a "500 - Internal Server Error".

In /var/log/sw-cp-server, I get these errors :

2017-08-21 15:53:14: (log.c.75) server started
DEBUGGER DETECTED... Bye!
2017-08-21 15:53:47: (mod_fastcgi.c.1000) the fastcgi-backend /usr/bin/sw-engine-cgi -c /usr/local/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm failed to start:
2017-08-21 15:53:47: (mod_fastcgi.c.1015) terminated by signal: 9
2017-08-21 15:53:47: (mod_fastcgi.c.1105) [ERROR]: spawning fcgi failed.
2017-08-21 15:53:47: (mod_fastcgi.c.3511) all handlers for /check-plesk.php on .php are down.
DEBUGGER DETECTED... Bye!
2017-08-21 15:54:11: (mod_fastcgi.c.1000) the fastcgi-backend /usr/bin/sw-engine-cgi -c /usr/local/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm failed to start:
2017-08-21 15:54:11: (mod_fastcgi.c.1015) terminated by signal: 9
2017-08-21 15:54:11: (mod_fastcgi.c.1105) [ERROR]: spawning fcgi failed.
DEBUGGER DETECTED... Bye!
2017-08-21 15:54:13: (mod_fastcgi.c.1000) the fastcgi-backend /usr/bin/sw-engine-cgi -c /usr/local/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm failed to start:
2017-08-21 15:54:13: (mod_fastcgi.c.1015) terminated by signal: 9
2017-08-21 15:54:13: (mod_fastcgi.c.1105) [ERROR]: spawning fcgi failed.

Thank you for your help.
 
Hi Khorne,

pls. check with "ps", that no orphaned "sw-cp-server" and "sw-engine" processes are existent and try to restart both services over your command line:

Code:
ps aux | grep sw-cp-server
ps aux | grep sw-engine

Kill possible existent processes with the example command:
Code:
kill -9 PID-NUMBER-AS-SHOWN-OVER-YOUR-COMMAND-LINE-WITH-THE-ABOVE-COMMANDS

Code:
service sw-cp-server restart

service sw-engine restart
... and investigate ( possible ) issues/errors/problems in your corresponding log - files.​
 
No orphaned processes found. I've run the restart, but

service sw-engine restart

give me this error : "sw-engine: service non reconnu"

Still got the 500 internal error and the almost the same error in log :

2017-08-21 17:38:55: (log.c.75) server started
DEBUGGER DETECTED... Bye!
2017-08-21 17:39:19: (mod_fastcgi.c.1000) the fastcgi-backend /usr/bin/sw-engine-cgi -c /usr/local/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm failed to start:
2017-08-21 17:39:19: (mod_fastcgi.c.1015) terminated by signal: 9
2017-08-21 17:39:19: (mod_fastcgi.c.1105) [ERROR]: spawning fcgi failed.
2017-08-21 17:39:19: (mod_fastcgi.c.3511) all handlers for /login_up.php3 on .php are down.
 
Hi Khorne,

I'm not sure, if Plesk 10.x already used the command
Code:
service psa restart
... which should restart all Plesk related services.


In addition, you could try to use the "bootstrapper - repair" - procedure, which can be initiated with for example:

Code:
/usr/local/psa/bootstrapper/ppXX.X.X-bootstrapper/bootstrapper.sh repair
... where XX.X.X has to be replaced with the latest bootstrapper - version at "/usr/local/psa/bootstrapper/".​
 
Did run both commands. Nothing changed, still error 500.

The repair procedure ends with :

Congratulations!
All stages of the upgrade were successful.
psa is now running on your system.
To complete the system configuration process, please proceed to URL:
[....]


Maybe to help some more detail about our system :

Plesk 10.4.4 on CentOS 5
PHP 5.2 shipped with CentOS 5 has been replaced with PHP 5.3 from Atomicorp. This was done years ago, and it always worked without any issues.
 
Last edited:
Hi Khorne,

even that I strongly recommend to upgrade your operating system AND Plesk as well, you could still ask for professional "Administrative services" from Plesk at:

 
I finally found the solution. I had to disable ptrace option in grsecurity.

So for those who might have the same problem :

- Execute the command :
# sysctl kernel.grsecurity.harden_ptrace
- If the result is "kernel.grsecurity.harden_ptrace = 1"
- Then do :

# echo "kernel.grsecurity.harden_ptrace = 0" >> /etc/sysctl.conf
# sysctl -p
# /etc/init.d/sw-cp-server restart
 
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