Nagios Support Forum

We have an active/standby configuration for our Nagios servers. The Standby has been reporting errors parsing the XML when monitoring the following on the Active server:
Load
I/O
Nagios XI Jobs
Nagios XI Daemons

A few minutes later, they all go back to normal.

Servers are running Nagios XI 5.5.4 on RHEL 7 64bit. We are monitoring 14,286 services and 854 servers. The issue appears to have started when we hit around 10,000 services/hosts monitored. We have the DB offloaded, rrdcached and RAMdisk enabled on the servers.

Any support or suggestions would be appreciated.

The checks use a php script called check_nagiosxiserver.php and on larger systems there can be issues parsing or applying configuration unless the php.ini is tweaked. https://support.nagios.com/kb/article/n ... e-611.html covers the modifications. I usually go a higher than the recommendation and do 100000 for max_input_vars.

Tweaks were already made:

max_input_time = 180
max_input_vars = 100000
memory_limit = 2048M
max_execution_time = 80

What does the load on the active machine look like ? Is the problem occurring during higher than usual loads?

Try running the check with the --debug=1 option to get more info the next time it fails.

Unfortunately, I can not get it to manually fail when the checks happen. It is pretty inconsistent, but frequent.

To give you an example, it has happened 8 times since Friday night, failed 2 checks each 4 minutes apart, then immediately gone to normal on the 3rd check.

The debug data will be part of the $LONGSERVICEOUTPUT$ macro and you can use this in notifications to make sure you get the output - https://assets.nagios.com/downloads/nag ... iables.pdf

will do.

Thanks. We'll be here

Thank you for your help. Changing from XML to JSON checks has helped and we have scheduled the update to 5.5.7 to fix the issue with the JSON checks.

No problem. For anyone else that may come across this, configuring the checks to use the API key will also force it to use JSON where this is fixed:

--address=$HOSTADDRESS$ --url='http://xi_ip/nagiosxi/' --apikey='api_key' --mode=daemons
--address=$HOSTADDRESS$ --url='http://xi_ip/nagiosxi/' --apikey='api_key' --mode=load --warn="5,4,4" --crit="10,10,7"
--address=$HOSTADDRESS$ --url='http://xi_ip/nagiosxi/' --apikey='api_key' --mode=jobs
--address=$HOSTADDRESS$ --url='http://xi_ip/nagiosxi/' --apikey='api_key' --mode=iowait --warn="5" --crit="15"

(replacing xi_ip and api_key with the appropriate values for your environment)

5.5.7 will also fix a similar PHP warning message caused when a check is flapping:

PHP Warning: simplexml_load_string(): v7301;CPU Usage;STOPPED; Service appears to have stopped flapping (4.0% change < in /usr/local/nagiosxi/html/api/includes/utils-api.inc.php on line 55