I'm in the process of planning a new IP Monitor installation, and working out how best to configure some of the dependancies to accomodate what I'm trying to achieve.
Basically, for most of the monitors I'll have all the relevant monitors for a each server in their own group, with the dependancies configured as that servers Ping monitor, the firewall in front of it, and yahoo.com (to confirm we have net access).
Where it gets complicated is that for a few of the servers we'll have POP3 QA monitors configured to test the individual mail servers, but since some of them pass the e-mail on to another server, we also want to monitor the pair as a whole. For instance, we have servers A and B. Both have POP3 QA monitors to confirm they are working with e-mail going direct to them. In addition we'll have a monitor which is configured such that e-mail is sent to server A, which then delivers it to server B from where we collect it, to test that the connection between those servers works correctly. Obviously the critical thing here is that if one of the two servers fails we do not want to receive an alert from the third monitor, as that would just confuse the engineer on call.
So obviously what I need to have is a group which has just the third A to B job as it's only member, but in terms of the dependancies, do I need to use all those dependancies mentioned above (server ping, firewall ping, yahoo ping) plus the server A and B POP3 QA monitors, or just add the two QA monitors? Eg, in the latter example, if server A's ping fails, the QA monitor for that group is also failed, but does that pass on down the line to other groups which have the QA monitor as a dependancy?
On a related subject, I notice that while the administrators guide says that a monitor can be a dependancy in multiple groups, you can also have monitors as members of multiple groups. Not sure why you'd do it, but if you did what would happen with any alerts? Eg, Server A's ping appears in group 1 and group 2, both of which are defined under the same alert. If a dependancy in group 1 failed alerting for the other monitors would obviously be disabled, but what if Server A's ping failed. Would it alert because it is a member of group 2 which isn't disabled, or would it not alert because it is disabled by group 1?