> Setup a page for monitoring
To minimize any performance hit, you can have a special page anywhere in your site which is of minimal size.
0 size might cause some problems, but anything else should work ok.
Or, if you already have a very small page (or even a small image), you could use that.
An advantage of that is that if you are doing any sort of accesslog viewing or analysis you can ignore
fetches of the monitoring page so you are only looking at "real" traffic.
