Monitoring Engine not running after attempted upgrade.

[DileepKumar]

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.

[kfanselow]

Hi Dileep,

Based on the output it looks like one of the dependancies for NDO is missing, a mysql library specifically.

Code: Select all

/lib64/libmysqlclient.so.21: version `libmysqlclient_21.0' not found (required by /usr/local/nagios/bin/ndo.so)

Make sure the mysql-libs.x86_64 package, or your distros equivalent, is installed and try restarting nagios core.

Code: Select all

systemctl restart nagios 

If it still is failing you can try rebuilding the ndo.so module from the xi-latest tar ball:

Code: Select all

cd /usr/tmp 
wget http://assets.nagios.com/downloads/nagiosxi/xi-latest.tar.gz

tar -xzvf  xi-latest.tar.gz
cd nagiosxi/subcomponents/ndo 

tar -xzvf ndo-3.1.1.tar.gz 
cd ndo-3.1.1 

./configure 
make 
make install 

Then restart nagios core:

Code: Select all

systemctl restart nagios 

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.

[DileepKumar]

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.