Multilocation monitoring - calculated items based on items from different hosts

[mitch2k]

Hi,

I want to monitor http response & web page loading times from 3 different locations (zabbix proxies).

I have setup the sites on the different proxies:


Via a template:



What I now want to do is to create a separate item which shows the average of the 3 items, and a trigger that only alerts if all 3 http checks are down.
I'm not 100% sure how to continue from here, and how I can make it easiest as I need to set it up for about 40 hosts. I think I should create a new template with calculated items. However I'm not sure which formula I need to use, and believe something like:

for response time: avg(last("HOST1:net.tcp.service.perf[http]")+last("HOST2:net.tcp.service.perf[http]")+last("HOST3:net.tcp.service.perf[http]"),30s) for availibility: (last("HOST1:net.tcp.service[http]")+last("HOST2:net.tcp.service[http]")+last("HOST3:net.tcp.service[http]")/3
However not sure if I can replace HOST by a placeholder in the template. Maybe via a macro? But, like I said, I'm not sure if this is the most efficient way to do this.

Thanks for any input!