Global variables question

A global variable is accessible from any iRule on any connection. You can create a separate iRule with a RULE_INIT event and reset the value of the global variable:

 
 when RULE_INIT { 
  
     Update the ::max_active_clients value without affecting the other iRule 
    set ::max_active_clients 2000 
 } 
 

There is an issue with that Codeshare example though:

In the current iteration of the rule, a new session is created and the total session count incremented on each HTTP request which doesn't already have a session cookie. The only time the total count is decremented is when the TCP connection is closed. So if there are multiple clients connecting over the same TCP connection (ie, coming in via a proxy), "session leakage" would occur. For proxied users, multiple sessions would be created, but only one session removed when the TCP connection is closed. To account for this, you'd have to count the number of new sessions created per TCP connection and then decrement the session count by this count in CLIENT_CLOSED.

Aaron