Application-gateways and URI based decisions - iRule, health monitor with aliases, or iControl?

I want to be careful not to be misleading if I misunderstand your request, but if you're asking what I think you're asking, then it can definitely be accomplished with a combination of health monitors and iRules. In fact, I have a similar architecture myself.

 

 

I have an HA pair of LTMs, which forward all traffic to a certain single sign-on environment to a pair of AGWs. Behind the AGWs are 7 Web Logic clusters, each for its own application. I have every one of those application clusters configured in their own pools on the LTMs, and I reference them in various iRules before forwarding the traffic.

 

 

Basically, the logic is like this: If the URI begins with "/text1" and if pool "app1" is up (meaning at least one member is functioning), then forward it to pool "AGW"; else take another action. Depending on the app, the LTMs either send their own HTTP response or they rewrite the URI and send to a web server which hosts static HTML pages for miscellaneous pre-written error pages. Rinse and repeat for each application, but in every case if the WS pool for that app is up the traffic always ends up being forwarded to the AGWs.

 

 

If my description above is similar to what you're looking for, we can talk about exactly how to implement it and what exact commands and logic the iRules contain.