iRule: Pool selection based on percentage active members available

Hello,

I've used active_members and members function for this scope, plus some math expressions. Tested in BIG-IPv13

# note: round() returned closest integer value in my tests, so with 2 members in pool expression result was 0.2 which was rounded to 0. This is why i added +1 in expression. With >10 pool members I think math should work fine

# EDIT - note 2 : ceil() TCL command could be a better fit but I'm not sure iRule support this. 

when CLIENT_ACCEPTED {

 # log local0. "active members: [active_members primaryPool]"
 # log local0. "total members: [members primaryPool]"
 # log local0. "minimum req. members: [expr round([members primaryPool]*0.1)+1]"
 
# note: round() returned closest value in my tests, so with 2 members in pool expression result was 0.2 which was rounded to 0. This is why i added +1 in expression. 
 
  if { [active_members primaryPool] >= [expr round([members primaryPool]*0.1)+1] }{
    pool primaryPool
  } else {
	pool secondaryPool
  }
}