Forum Discussion
Shay_Ben-David1
Nimbostratus
NimbostratusHTTP limit does not reduce sessions
Hi, i used the HTTP session limit on my web, but i can't figure why the total connection of the hhtp does not reduce, but only increased and after few minutes the site can not serve, and i have to remove the irule ?
rule HTTP_session_limit {
when RULE_INIT {
set ::total_active_clients 0
set ::max_active_clients 100
log local0. "rule session_limit initialized: total/max: $::total_active_clients/$::max_active_clients"
}
when HTTP_REQUEST {
; test cookie presence
if {[HTTP::cookie exists "ClientID"]} {
set need_cookie 0
set client_id [HTTP::cookie "ClientID"]
; if cookie not present & connection limit not reached, set up client_id
} else {
if {$::total_active_clients < $::max_active_clients} {
set need_cookie 1
set client_id [format "%08d" [expr { int(100000000 * rand()) }]]
incr ::total_active_clients
; otherwise redirect
} else {
HTTP::redirect "http://sorry.domain.com/"
return
}
}
}
when HTTP_RESPONSE {
; insert cookie if needed
if {$need_cookie == 1} {
HTTP::cookie insert name "ClientID" value $client_id
}
}
when CLIENT_CLOSED {
; decrement current connection counter for this client_id
if {$::total_active_clients > 0} {
incr ::total_active_clients -1
}
}
}
3 Replies
David_Horton_20Hi
I have also had a few problems with this rule (strangely I was having the opposite problem) and have found it more reliable to increment and decrement the total_active_clients using the "when CLIENT_ACCEPTED" and "when CLIENT_CLOSED" events.
Hope that helps, I did get end up with a rule that works pretty well eventually.
Dave
mlick2What actually triggers the CLIENT_CLOSED event? I am using this same iRule and I am seeing that within 5 - 20 seconds of the HTTP_REQUEST, the CLIENT_CLOSED event is triggered and my user count is decremented by 1. Therefore I am not keeping an accurate count of how many active sessions there are because my count is back down to 0 and within a few seconds another round of users are allowed to get a cookie and pass through.- David_Horton_20I encountered exactly the same problem, I not sure what triggers the event myself, it does seem to vary according to serveral factors (client browser, traffic level, etc.). I got around it by using CLIENT_ACCEPTED to increment and CLIENT_CLOSED to decrement, this is not 100% reliable but is good enough, I just reset my count every so often (couple of times a month) using the count in the statistics page to keep it accurate.
