In this case your first idea about url matching is absolutely correct.
L7 class map
class-map type http loadbalance L7-C
match http url /123
than you have serverfarm S1 which contains both of your servers and serverfarm S2 with contains only server #1
then in L7 policy map :
policy-map type load fir L7-p
class L7-C
serverfarm S2
class class-default
serverfarm S1
And than use it for necessary VIP
One note regarding URL matching (from my experience it's quite often confusing
)
E.g. you have url in your browser like: http:/myweb.com/test/test.php
however when browser opens a connection - this URL can't be seen anywhere, it will be used like this :
-IP address of myweb.com will be determined and used in L3 header
- in L7, http header this part myweb.com will be used in header field "Host"
- this part /test/test.php will be placed in GET request , like GET /test/test.php HTTP1.1 (e.g.)
So, url matching in ACE actually matches part which is in GET field , so you can't put there something like http://myweb.com/test/test.php, as host part is never in GET field. And actually URL as we see it in browser is never sent.
