Help with an iRule to log RPC activity

I am trying to differentiate between the RPC connections that are open and passing active traffic to the RPC connections that are open and not passing traffic but being kept open based on a server keep-alive setting. I think if I can track an open connection and construct a timechart or capture total count of event/traffic since open, I could solve the question.

I am seeking assistance on an constructing an iRule or advice on a different approach. Thank You!