Metrics Reporting - Load Balancing Considerations

I have to report Network Availability Metrics on a monthly basis.  My current reports do not consider any load balancing in the calculations.  I would like to be able to do that, but don't really know where to start.  For example, let's say that I have Server 1 and Server 2 that are load balanced for Service 1.  Now if Server 1 becomes unavailable (reboot, crash, or etc...) which is unplanned, my Service 1 is still available and there is no interruption of service.  I want to be able to capture that in my metrics.  Currently, I gather all of my availability data as a percentage and I sum the percentages and divide by the total number of nodes monitored.  So in this case if Server 1 becomes unavailable, Service 1 is unavailable for that node, but that is not a true reflection of the availability of Service 1.  My calculation would be

Service 1          Server 1          95%

Service 1          Server 2          100%

Availability = 97.5%

when in actuality my Availability for Service 1 is 100%.  How do I account for load balancing, like in the example, in Report Writer?  Can it even be done?  How does everyone else handle this type of situation?

Message was edited by: Lamar Ross