iRule to cap traffic on VIP to 10Mbit/s with HTML OOS response if limit exceeded

I developed this iRule, it seems like counter now works properly. Can someone cast an eye for efficiency and whether iRule makes sense?

 

Thanks,

 

when HTTP_REQUEST {

 

set limit 10000000

 

set tbl "rate_limit"

 

set key [expr {[IP::stats bytes in]}]

 

 

Sum up values function

 

foreach element $key {

 

log local0. "Per request rate is: $element"

 

lappend IP [expr (0 + {$element})]

 

set sum [expr [join $IP +]]

 

log local0. "Sum of all requests is: $sum" }

 

Bandwidth cap condition

 

if {$sum >= $limit} {

 

HTTP::respond 200 content {

 

 

 

OOS page

 

 

 

Sorry, page is currently OOS, please refresh in a while...

 

 

 

}

 

table delete -subtable $tbl $key

 

log local0. "dropping..."

 

TCP::close

 

} else {

 

table set -subtable $tbl $key "new_tbl" 2 2

 

}

 

}