Nagios Support Forum

I created a SNMP service and assigned it to a service group but quickly found that I could not assign the group to a host or host group. I could only assign a host group to the service and then when I assign the host group to a device the checks incorporated are assigned to the device.

What is the point of a Service Group?

Theoretically the ideal for service groups is the same as host groups but just for services. To add a little onto what kg said it can also be used to group similar objects together for viewing. For example if you wanted to see the cpu usage for a group of servers you can make a service group and put in all the related cpu service checks into the group. Here is some documentation on object configuration that may help.

Thanks. I reviewed the link provided by sgardil and it validated what I was thinking about grouping services (and hosts), but I'm still confused about why I couldn't use the service group I created.

Perhaps describing in greater detail what I did will help.

I wanted to monitor the PSU's (Power Supply Unit) of our Dell servers. These are monitorable through SNMP, via the iDRAC. To do that I setup a SNMP query to poll the PSUs every five minutes. Unfortunately, the OID for PSU1 and PSU2 are different (the last integer increments by one) which required making two distinct services. I instinctively grouped them together thinking that I'd be able to assign the group to the host group. But that is where I ran into the issue that I couldn't assign the service group. Hence, my confusion of their purpose.

Maybe I missed an intermediary step?

At any rate I've assigned both of the new services to the host group and assigned the host group to all of our iDRAC's so the PSU's are now alerting in Nagios.

Hi @KWGagel,

What were you trying to accomplish via service groups? Based on your description, I imagine you were aiming at treating these two services as one, correct? Why would you want these two oids to be treated as one service? Perhaps I am misunderstanding, but if you could clarify, we might be able to suggest a solution alternative to service groups.

Or, based on your last sentence, have you already found a solution with which you are satisfied?

Thank you!

For each Dell server we have, there are two power supplies installed for redundancy. I was trying to setup an alert in Nagios to let us know one of the two have failed. Thus, drawing attention to the server to the person on call.

Once the on-call person is alerted they have to login to the iDRAC to verify details so the actual PSU# isn't really relevant until then.

Yes, I have a solution, but I was still trying to understand the purpose of service groups if I can't actually use them by assigning them to a host group. What are they for if I can't do anything with them?

Service groups are primarily aimed at making it easier to view and configure related services. For example, various graphs and dashlets in XI can be organized by service groups and various config options can be applied via service groups rather than requiring individual service configurations.

While I cannot make changes to the services within a service group - I can make a report that uses the service group which then displays the aggregated information.

OK, I think I understand the uses of service groups vs host groups.

Thank you.