Nagios Support Forum

Hi everyone,

When i tried to upgrade my Nagios XI to the latest version, it succesfully got upgraded but monitoring agent is failed.

below is the logs

/usr/local/nagios/var/nagios.log


[1777443725] wproc: Registry request: name=Core Worker 3560733;pid=3560733
[1777443725] wproc: Registry request: name=Core Worker 3560736;pid=3560736
[1777443725] Error: Could not load module '/usr/local/nagios/bin/ndo.so' -> /lib64/libmysqlclient.so.21: version `libmysqlclient_21.0' not found (required by /usr/local/nagios/bin/ndo.so)
[1777443725] Error: Failed to load module '/usr/local/nagios/bin/ndo.so'.
[1777443725] Error: Module loading failed. Aborting.


Before starting the upgrade I have enabled myql using below command

dnf module enable mysql -y

Below is the nagios status


systemctl status nagios

× nagios.service - Nagios Core 4.5.12
Loaded: loaded (/usr/lib/systemd/system/nagios.service; enabled; preset: disabled)
Active: failed (Result: exit-code) since Wed 2026-04-29 11:52:07 IST; 16min ago
Duration: 32ms
Docs: https://www.nagios.org/documentation
Process: 3560654 ExecStartPre=/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg (code=exited, status=0/SUCCESS)
Process: 3560710 ExecStart=/usr/local/nagios/bin/nagios -d /usr/local/nagios/etc/nagios.cfg (code=exited, status=0/SUCCESS)
Process: 3560742 ExecStopPost=/bin/rm -f /usr/local/nagios/var/rw/nagios.cmd (code=exited, status=0/SUCCESS)
Main PID: 3560711 (code=exited, status=1/FAILURE)
CPU: 429ms

Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Checked 34 timeperiods
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Checking global event handlers...
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Checking obsessive compulsive processor commands...
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Checking misc settings...
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Total Warnings: 0
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Total Errors: 0
Apr 29 11:52:05 NagiosXI_HOST nagios[3560654]: Things look okay - No serious problems were detected during the pre-flight check
Apr 29 11:52:05 NagiosXI_HOST systemd[1]: Started Nagios Core 4.5.12.
Apr 29 11:52:05 NagiosXI_HOST systemd[1]: nagios.service: Main process exited, code=exited, status=1/FAILURE
Apr 29 11:52:07 NagiosXI_HOST systemd[1]: nagios.service: Failed with result 'exit-code'.



please find the upgrade summary in the attached text file

Could anyone, please help me out here.

Hi Dileep,

Based on the output it looks like one of the dependancies for NDO is missing, a mysql library specifically.
Make sure the mysql-libs.x86_64 package, or your distros equivalent, is installed and try restarting nagios core.
If it still is failing you can try rebuilding the ndo.so module from the xi-latest tar ball: Then restart nagios core:
If this doesn't work you will want to open a case with our support team so they can take look at the specifics of your system.

https://supportportal.nagios.com/s/

Thanks and kind regards.

Hey @kfanselow,

Thank you so much,

I have tried rebuilding the ndo.so module from the xi-latest tar ball and nagios monitoring engine is now working.

Thank You.