How to detect and alert current connections per virtual server?!

I have one question how to detect and alert current connections per virtual server?

 

I think using iCall or iRule...

 

But I think it is not effective... Becuase the count of virtual servers is about 500 and the virtual server is very frequently created and removed.

 

So above two methods are very none-effective I think.

 

And I would like to know best method to resolve it.