HTTPRequestThrottle Issues

You would want to add some kind of logic to either or both iRules to ensure that if you're redirecting the client to the maintenance page that you don't try to insert an HTTP header in the request. One option is to use a local variable to track that you're sent a redirect:

 
  Maint page lite rule 
 when HTTP_REQUEST priority 400 { 
  
  Run this rule event before other HTTP_REQUEST events so we can allow this rule to send a redirect 
 set redirected 0 
  
 ... 
  
     If the pool_testLB is down, redirect to the maintenance page 
    if { [active_members pool_testLB] < 1 } { 
       set redirected 1 
       HTTP::redirect "http://$host/maintenance" 
       return 
    } 
 

Then in the HTTP request throttling rule, before you send a redirect or insert an HTTP header, you could check to see that $redirected is 0.

 
 if {$redirected==0} 
     Insert HTTP header or send client a redirect 
 } 
 

Aaron