Does nagios XI still only read its config at startup/reload?

[rkcarter]

Hi,

A colleague asserts that, with nagios XI, it's vitally important to minimize config file sizes, that nagios xi continually passes through the config so every optimization will help at run-time (granted, either way, optimizations might help at reload time, but we're talking something that takes seconds once every config change, and I get that, but that's trivial). From what I can find out, nagios xi reads the config only when starting up or being told to reload it (which I can find is definitively true for Nagios Core, but I can't find any such statement about XI). Who is correct here?

(more detail for those who care how this came up...)

He's trying to get me to optimize some checks/services/servicegroups/service templates in very unclear ways, even though the result will generate the exact same set of checks, just with a few fewer stanzas in the config file. He just sent me a very convoluted diagram he wants me to optimize to make the config file smaller, and after years of nagios, even I am having trouble figuring out all the ins and outs of how this is supposed to work -- all to save a half dozen service stanzas. It's basically a nonprod/prod set up with differing contact destinations for hosts vs. services/prod vs. nonprod, and I've got prod and nonprod services duplicated, with servicegroups needed for some of the services in prod in one and some of the services in nonprod for one. If my assumption is correct, it's a waste of a few hours to little avail; if his is correct, of course I'd want to optimize it for all time.

So, can someone tell me, does XI actually constantly read the config files while running? Or just once when it's started up or otherwise explicitly "told" to?

[benjaminsmith]

So, can someone tell me, does XI actually constantly read the config files while running? Or just once when it's started up or otherwise explicitly "told" to?

Hi @rkcarter,

When you Apply Configuration changes to Nagios Core, the config files are re-written to the objects.cache to speed up file caching and allow to edit current config files while Nagios is running. In Nagios XI, this data is stored in a database for increased performance and updated during changes. We have systems deployed with thousands of hosts and services checks, so this is not something to be overly concerned with.

However, you can take adavantage of template hierarchy when setting up your system to minimize configuration file size and simply administration of network monitoring. For example, you can use service template for base settings to apply all other services or a service group.

Some documentation on templates in Nagios XI
https://support.nagios.com/kb/article/n ... s-508.html

Let me know if you have any other questions.

[rkcarter]

Thanks, I get all that. What was slightly opaque to me was whether nagios XI handled the files in any substantively different way than nagios core (which my colleague asserted). Glad to know that under the hood it's all about the same.

[benjaminsmith]

Hi @rkcarter,

Great, did you have anymore questions, or is it alright for us to close this forum topic?