Checking response times before sending data to a pool

Here we go again

 

 

Is there any easy way, using iControl or iRules to check the response time of a particular request against many pools, before desatching the client data to any particular pools or nodes?

 

 

A client needs to PoC this and I don't know where to start. The pools may represent nodes across two sites, and by default we want to send client requests to the closest geographical pool, unless the response times are poor, in which case we want to send to one of the other pools. We have to try to achieve sub-second response times.

 

 

Any help will stop me going bald