This is true, one can architecture servers such that things like file
handle limits do not apply, but there is still an increase in CPU
usage when connections are left open. I have never measured the
different loads, but I would guess that the overhead of having open
connections, and the overhead of multiplt connections/terminations is
much the same. Is there any real evidence of which incurs more
overhead? My guess is that the results might differ very much
depending on how the kernel implements things like accept(), select()
et al....