On Tue, Feb 19, 2002 at 07:24:09PM +0100, Marcel de Vries wrote:
> After 4 hours of pinging and listening to a shoutcast stream natd rised to
> his state of eating 34% proctime (top)
> Connection timed out, did a restart of mpd and everything is running normal
> agian.
somewhat unrelated, but... why are you using both mpd and natd ?
wouldn't mpd do the address translation same as ppp does ?
Anyways the performance problem could be easily explained by
a poor implementation of the session lookup in libalias -- e.g.
resulting in heavy scanning of long lists for each received packet,
or things like that.
>From the (almost non-existent) comments in the libalias code it is
not immediate to understand what is the underlying data structure
-- maybe a hash table followed by lists -- nor if there are variables
that one could monitor to see how the lookup strategy works (e.g.
number of entries, average depth of the lists, etc.
> > - i'm not an expert but truss, strace and grof show that most of the time
> >is spent in sendto() ...
This is probably related to a problem in natd which was fixed by
Ruslan not long ago in current, and did not make it in RELENG_4_5
(it is in -stable though).
The bug was that natd looped around a select which would always
return the socket as writable, and it would keep retrying a sendto()
until successful.
The fix is to drop the packet when sendto fails, and rely on retransmissions
instead.
cheers
luigi
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-net" in the body of the message
