Terminate TCP Sessions

i applied the following irule to the virtual server

 
 when RULE_INIT { 
     set ::count 0 
   } 
  
 when CLIENT_ACCEPTED { 
    if { [active_members pool_a] > 0 } { 
       pool pool_a 
      log local0. "primary active" 
    if { $::count == 1 } { 
        log "clean sessions" 
       set ::count 0 } 
      
    } else { 
       pool pool_b 
  log local0. "secondary active"  
  set ::count 1   
    } 
 } 
 when LB_FAILED { 
    pool pool_b 
  set ::count 1   
  log local0. "Selected member: [LB::server addr]"    
 } 
 

on the bigip itself i listen for the string 'clean sessions' in the ltm log, which triggers the bigpipe command as descibed in the solution.

cheers