CMP compatible strict Round Robin

To answer your questions:

 

You can't access the session table in RULE_INIT or any other global event, that's true. However, don't forget that entries in the session table deliberately expire, so even if you could initialize them in RULE_INIT, they may be gone later, and your iRule has to cope with that (that's one reason there are so many variations on things like the set command). Fortunately, the table commands are written with that in mind as well, and tend to Do The Right Thing in the case where there is no existing entry. To give one example (that will become relevant shortly), if you do something like increment a key that doesn't exist, it automatically starts it as 0.

 

I don't think there is a way to explicitly say that a value is a string or a number; Tcl generally converts automatically when necessary. However, I can't see where you're running into this problem. Could you elaborate a bit?

 

Yes, to set variables in RULE_INIT, just use "set static::myvarname myvalue".

 

As for your round-robin iRule, I think that you're waaaaaay overthinking this. How about something like:

when CLIENT_ACCEPTED {
  set poolname "test-pool"

  if { [active_members $poolname] < 1 } {
     No active pool members; reset client
    reject
    return
  }

  set count [members $poolname]
  set attempt 0
  while { $attempt < $count } {
    set num [table incr "round-robin:$poolname"]
    set num [expr $num % $count]
    set mbr [lindex [members -list $poolname]]
    set mbr_ip [lindex $mbr 0]
    set mbr_port [lindex $mbr 1]
    if { [LB::status pool $poolname member $mbr_ip $mbr_port up } {
      pool $poolname member $mbr_ip $mbr_port
      return
    }
    incr attempt
  }
}

Again, not actually tested or syntax-checked code, and written for clarity, not compactness or performance.