How to get the response size after gzip compression

Hi Talne,

if the responce content is not

chunked

, then you may use the Content-Length header value of the

HTTP_RESPONSE_RELEASE

event. Below is a simple iRule which analyses the Content-Length during

HTTP_RESPONSE

and

HTTP_RESPONSE_RELEASE

event and then performs rocket science to output the compression ratio...

when HTTP_REQUEST {
    set http_path [HTTP::path] 
}
when HTTP_RESPONSE {
    set content_l [HTTP::header value "Content-Length"]
}
when HTTP_RESPONSE_RELEASE {
    if { ( [HTTP::header value "Content-Length"] ne "" ) and ( $content_l ne [HTTP::header value "Content-Length"] ) } then {
        log local0.debug "Path: $http_path Comperssion Ratio: [expr { [HTTP::header value "Content-Length"] / ( $content_l / 100 ) }]%"
    }
}

Note: If you need to analyse the compression ratio of chunked content, then you could experiment with a VIP-targeting-VIP setup where the serverside VIP compresses the content and the clientside VIP analyses the transmited payload of the serverside VIP.

Cheers, Kai