Is there any way in an iRule to tell if APM is enabled or disabled on a connection?

Hi,

if you want to do some stuff when APM is enabled, you can do it on ACCESS_ACL_ALLOWED event.

this event raise every time the request is associated with APM session and not dropped by ACL (if no ACL is defined or explicit ACL allow the request)

you can also use this irule :

when HTTP_REQUEST {
    set apm_enabled 0
}

when ACCESS_ACL_ALLOWED {
    set apm_enabled 1
}

when HTTP_REQUEST_SEND {
    log "APM Status is $apm_enabled"
}