Nagios Support Forum

Good afternoon guys,

As I am new to Nagios, I would like to ask if anyone knows how to monitor 2 physical locations using Nagios.

So for example, we are having 2 datacenters which are interconnected. I have set-up a Nagios server which will monitor the services on both datacenters.

However, let's say for example Datacenter 1 the connectivity is down, therefore you wouldn't be able to see the other Datacenter.

What I am trying to do is that I would like to monitor both datacenters individually, how should I go about that? Having 2 Nagios server installations or?

Thank you very much for your help.

Regards, Cip

Two separate servers will be the easiest, but maybe I am not understanding. Are you looking for a unified view of the two Nagios servers? For that you could use Fusion:

http://www.nagios.com/products/nagiosfusion

@tmcdonald

Hi and thank you for your fast reply.

You are on the right path with regards to having 2 Nagios servers, as I've concluded from my research. However, also I have found out that you can have 2 servers where one of them will be passive and the other one will be active (active / passive checking) and both of them could be unified using this Nagios plugin: http://mathias-kettner.de/checkmk_multisite.html

Am I right or do you have something to add?

Thank you once again,

Regards,
Cip

I've never used check_mk so I don't have any great knowledge of it. I know that it adds features but also complication when things go wrong. I'm not wanting to discourage you from following that method to achieve your goal, just be aware that when you add moving parts to a system, and those moving parts are manufactured by someone in a different country (literally) it can become more troublesome to resolve issues as they arise.

With that said, active/passive checking can in a roundabout way be used to achieve your goal. It's not terribly uncommon to have a nagios instance running active checks submit passive results to another instance to achieve multisite existence. What you're seeking is to have all services in both sites though? Is that right? This really doesn't give you a whole lot more information that just 1 server would give you though:

"Everything in datacenter 1 is OK, but datacenter 2 is gone" - there is no need for a 2nd server to give you that information. How does that information differ from what you actually seek? The problem with monitoring all services in both locations is duplicate services everywhere, how do you know who or what to trust?

@jdalrymple,

Thank you for your quick reply.

Well indeed your solution to my problem is what many people out there are doing at the moment as I have seen many posts regarding this but I had to ask as I was unsure.

Regarding the Datacenter 1 and 2 problem, well as I have mentioned we have got 2 datacenters which are interconnected. If the connection between the Datacenter 1 and Datacenter 2 goes down, you will get lots of notifications saying that the services for the respective node are down. However, they " aren't down " just the connection between these 2 datacenters is down which brings me back to the possibility of having 2 Nagios servers and yes I must agree with you, as this solution will result in duplicate services.

Thank you once again,

Regards,
Cip

One thing to be aware of is our reachability logic - it will handle all of the hosts/services behind the WAN link to prevent you from getting barraged with alerts when that link goes down.

Does this answer all your questions? If so we'll lock this topic up.

@jdalrymple

Thank you once again for your great advice, indeed it is making me understand how I should setup them and please feel free to mark this thread as completed.

Thank you and have a great day / evening.

Regards,
Cip