Can I force active connections to read an iRule after it has been changed?

The example would be: adding log messages to an iRule for diagnostics. I guess I could add a data group for log messages (seems like overkill).

if {[class match [string tolower [HTTP::host]] ends_with log-diagnostic]} { 
    set logmessage [class match -value -- [HTTP::host] ends_with log-diagnostic]
log local0. "$logmessage "
}

Data Group String: test.host.org := "Address [HTTP::host][HTTP::uri] REFERER [HTTP::header "Referer"] Client IP Address: [IP::client_addr] "