irule keep-alive hash pool reselection

Hi,

 

Is it possible to create an irule on a keepalive hash to reselect a pool member based on the hash value changing, for example if the main webpage content changes to a maintenance page the users will be redirected to another webserver serving the proper content, anything other than the proper website will be redircted

 

The requirement is similar as below migrating from CSS to F5, which suggests using a montior,although if the service will be marked as down it will not re-direct requests to another webserver

 

https://devcentral.f5.com/questions/converting-cisco-css-monitor-to-f5-irule