Date: Tue, 5 Jul 2011 02:14:51 +0700 From: Eugene Grosbein <egrosbein@rdtc.ru> To: Adrian Minta <gygy@stsnet.ro> Cc: freebsd-net@freebsd.org Subject: Re: FreeBSD 8.2 and MPD5 stability issues - update Message-ID: <20110704191451.GA12372@rdtc.ru> In-Reply-To: <813678a855c90c49bf66c7084f88b45d.squirrel@mail.stsnet.ro> References: <813678a855c90c49bf66c7084f88b45d.squirrel@mail.stsnet.ro>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jul 04, 2011 at 08:16:19PM +0300, Adrian Minta wrote:
> >It seems, enough. But, are you sure your L2TP client will wait
> >for overloaded daemon to complete connection? The change will
> >proportionally increase responsiveness of mpd - it has not enough CPU
> >horsepower to process requests timely.
> >
> >Eugene Grosbein
>
> Actually something else is happening.
>
> I increased the queue in msg.c
> #define MSG_QUEUE_LEN 65536
You can't do this blindly, without other changes.
For example, there is MSG_QUEUE_MASK in the next line
that must be equal to MSG_QUEUE_LEN-1 and effectively
limits usage of this queue.
> ... and in the ppp.h:
> #define SETOVERLOAD(q) do { \
> int t = (q); \
> if (t > 600) { \
> gOverload = 100; \
> } else if (t > 100) { \
> gOverload = (t - 100) * 2; \
> } else { \
> gOverload = 0; \
> } \
> } while (0)
>
> Now the overload message is very rare, but the behaviour is the same.
> Around 5500 sessions the number don't grow anymore, but instead begin to
> decrease.
You should study why existing connections break,
do clients disconnect themselves or server disconnect them?
You'll need turn off detailed logs, read mpd's documentation.
Also, there are system-wide queues for NETGRAPH messages that can overflow
and that's bad thing. Check them out with command:
vmstat -z | egrep 'ITEM|NetGraph'
FAILURES column shows how many times NETGRAPH queues have been overflowed.
One may increase their LIMIT (second column in vmstat's output)
with /boot/loader.conf:
net.graph.maxdata=65536
net.graph.maxalloc=65536
Eugene Grosbein
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110704191451.GA12372>