httpd: Syntax error - undefined symbol: ap_unixd_mpm_set_signals

clauuudiu

Registered
Jul 18, 2017
2
1
3
Bucharest
cPanel Access Level
Root Administrator
Hello,
I'm not a very advanced linux user, but I'm using cpanel/whm for about 5 years. For about 6 months I have a dedicated server. All was ok until today.
I think tonight there was an update for cpanel/whm and suddenly there's an issue with httpd.. it cannot start.
It says :
Starting Apache web server managed by cPanel EasyApache...
Jul 19 02:38:30 root.srvcontrol.com restartsrv_httpd[26240]: httpd: Syntax error on line 25 of /etc/apache2/conf/httpd.conf: Syntax error on line 2 of /etc/apache2/conf.modules.d/000_mod_mpm_prefork.conf: Cannot load modules/mod_mpm_prefork.so into server: /etc/apache2/modules/mod_mpm_prefork.so: undefined symbol: ap_unixd_mpm_get_retained_data
Jul 19 02:38:30 root.srvcontrol.com systemd[1]: httpd.service: control process exited, code=exited status=1
Jul 19 02:38:30 root.srvcontrol.com systemd[1]: Failed to start Apache web server managed by cPanel EasyApache.
Jul 19 02:38:30 root.srvcontrol.com systemd[1]: Unit httpd.service entered failed state.
Jul 19 02:38:30 root.srvcontrol.com systemd[1]: httpd.service failed.

I tried rebuilding apache using EasyApache4 but I get the same error during provisioning.
I get the same when I restart httpd from ssh.
I also tried switching to worker mpm, but then the error appears again just with "cannot load mod_worker..... instead of prefork.. so I don't think it's related to prefork, but to the process of loading modules.
The file 000_mod_mpm_prefork.conf contains only this:
# Enable mod_mpm_prefork
LoadModule mpm_prefork_module modules/mod_mpm_prefork.so
So I doubt there's any syntax error.
Any help is welcome.
Thank you
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,904
2,219
463
Hi @clauuudiu,

Do you mind opening a support ticket so we can take a closer look? Additionally, could you post the ticket number here after opening the ticket so we can update this thread with the outcome?

Thank you.
 

clauuudiu

Registered
Jul 18, 2017
2
1
3
Bucharest
cPanel Access Level
Root Administrator
Hello
I have opened a support ticket last night and the issue was fixed. It seems that the symlink between /etc/apache/logs was removed during the update and was made a directory. . The ticket number is 8728295. All good now, thanks to cPanel support :)
Thank you
 
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cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,904
2,219
463
Hello,

To update, internal case EA-6560 is open to track reports of the following path existing as a directory instead of as a symbolic link:

/etc/apache2/logs

The workaround is to move the directory to another location, setup the symbolic link, and update the EA4 packages using commands such as this:

Code:
mkdir -p /etc/apache2-logs-backup
mv  /etc/apache2/logs  /etc/apache2-logs-backup/
ln -s /var/log/apache2 /etc/apache2/logs
yum update
Then, once everything is confirmed to work as expected, review the contents of the /etc/apache2-logs-backup/ directory and remove it after confirming none of the data in it is required.

I'll monitor the status of the internal case, and update this thread with more information as it becomes available.

Thank you.