Http Health monitor

I suggest to use a specific receive string. If the receive string is left blank, it will accept any response the server sends back, including error pages (like 4xx/5xx server errors) as valid responses, and will mark the server up. Typically only timeout marks the server down with empty receive string.

You can use some info string from the header part of the response, like 200 OK, or any unique text string from the beginning of the normal response page. Use fiddler, firebug or similar tool to check what a valid response page sends (including headers).

The default http monitor buffer size is 5120 bytes, so the receive string needs to appear within that, especially before any images on the rendered response page.