Lightboard Lessons: BIG-IP Pool Priority

We received a Facebook question on Sunday asking about BIG-IP Pool Priority.  The scenario is this:  you have a pool with 9 pool members and three priority groups defined (three pool members per priority group) and minimum active members set to 2 (see details below).  If the pool members start going down (disabled for some reason), then how does the BIG-IP handle the load balancing for the remaining active pool members?  In this edition of Lightboard Lessons, we dive into the details of how all this happens.  

Here's the configuration in the question:

pool my_pool {

lb_mode fastest

min active members 2

member A-IP priority 1

member B-IP priority 1

member C-IP priority 1

member D-IP priority 2

member E-IP priority 2

member F-IP priority 2

member G-IP priority 3

member H-IP priority 3

member J-IP priority 3

}