The percentage of the total number of "active member", execute the TMSC modify command.

Do you mean physical NIC's on the F5?

I'm not sure you can easily do it, or if it would be supportable or why you would want to.

I'd suggest using iControl is the way to go if you are someone in the team has some coding skills (or wants to learn): https://devcentral.f5.com/icontrol/getting-started

this is actually a great use case for an iCall script. You can use a periodic icall handler to kick off a script every x number of minutes, and if percentage of available members drops below your threshold, the script can initiate a a shutdown of the interface.

You'll need to customize to only actually modify when there is a change in state rather than because the status is above/below the threshold (as I've shown below with the simple if/else condition), but this should get you started down the path:

  foreach pn $pool_names {
     set total 0
     set usable 0
     foreach obj [tmsh::get_status /ltm pool $pn detail] {
         foreach member [tmsh::get''field''value $obj members] {
            incr total
            if { [tmsh::get''field''value $member pool-member.status.availability-state] == "available" &&
                 [tmsh::get''field''value $member pool-member.status.enabled-state] == "enabled" } {
                     incr usable
               }
         }
     }
     if { [expr $usable.0 / $total] < 0.7 } {
    tmsh::modify /net interface 1.1 disabled
     } else { tmsh::modify /net interface 1.1 enabled }
  }

Here's the writeup as promised.