what reverse proxy server will direct traffic to healthy servers whose health is based on a result string??
ideally i'd like something like dnsmadeeasy or ultradns - lol - but for reverse proxy
i have looked at pound, delegate, ha proxy, squid, varnish, nginx, apache, and cherokee but can't see that they will work - they only test for HTTP result code
client request www.aaa.com
www.aaa.com is a reverse proxy
reverse proxy looks at "test.php" on server 1.aaa.com, 2.aaa.com and 3.aaa.com for result string "OK"
if the server is "OK" then proxy requests to them