Hi,
In case of CSS:
in the case of http keepalive, if using persistent the CSS only open 1 connection and simply send a new HTTP request every frequency-interval.
But with ACE we always close the connection after the probe is complete.
You can say that HTTP probe with ACE is always non-persistance.
You can only choose the method of closure. By default ACE close the connection gracefully.
Hope that helps.
regards,
Ajay Kumar