persisting the jsessionid cookie within F5 session table

 
when HTTP_REQUEST {

  set sid ""
  set hostid [getfield [HTTP::host] "." 1]
  if { [HTTP::uri] starts_with "/static" } {
     HTTP::respond 200 OK
  } else {
    set key [URI::query [HTTP::uri] "f5key"]
    if {$key != ""} {
        if f5key is present in query parameters
        persist the request first
       persist uie "$hostid$key"
       set path [URI::decode [URI::path[HTTP::uri]]]
        retrieve the jsessionid cookie value from F5 session table
       set sid [table lookup "$key$hostid"]
        insert the cookie value so that application can reuse it
       HTTP::header insert Cookie "JSESSIONID=$sid"
        update the URI without query parameters
       HTTP::uri $path
    }
  }
}

when SERVER_CONNECTED {

   I chose 1200 as timeout because application 
   has 20mins as session idle timeout
  set prid [table add "pkey$hostid" 5999 1200]
  if { $prid < 6300 } {
    set prid [table incr "pkey$hostid"]
     create persistence record based on hostname and key
    persist add uie "$hostid$prid" 1200
  }
}

when HTTP_RESPONSE {

  table add "skey$hostid" 5999 1200
  if {$key != ""} {
     set cid $key
  } else {
     set cid [table incr "skey$hostid"]
     if { $cid > 6300 } {
        set cid [table set "skey$hostid" 6000 1200]
     }
  }

  if JSESSIONID shows up in set-cookie header 
  store it in F5 session table
  if { [HTTP::cookie exists "JSESSIONID"] } {   
    set sid [HTTP::cookie value JSESSIONID]  
    table set "$cid$hostid" $sid 1200
  }

  if { [HTTP::status] starts_with "3" } {
     set location [URI::decode [HTTP::header Location]]
      pass the key as query parameter
     set query "?f5key=$cid"
     set newLocation "$location$query"
     HTTP::header replace Location $newLocation
  }

}