Re: Doubts about listen backlog and tcp_max_syn_backlog

From: Vijay Subramanian
Date: Mon Jan 28 2013 - 00:26:39 EST


> + { "ListenDrops", N_("%u SYNs to LISTEN sockets dropped"), opt_number },
>
> (see the file debian/patches/CVS-20081003-statistics.c_sync.patch
> in the net-tools src)
>
> i.e., the netstat pkg is printing the value of the TCPEXT MIB counter
> that's counting TCPExtListenDrops.
>
> Theoretically, that number should be the same as that printed by nstat,
> as they are getting it from the same kernel stats counter. I have not
> looked at nstat code (I actually almost always dump the counters from
> /proc/net/{netstat + snmp} via a simple prettyprint script (will send
> you that offline).
>

nstat pretty much does what you describe which is to parse the
/proc/net files(s) and
print the contents. This is one advantage of nstat over netstat. When
you add a new MIB, you
do not need to update nstat.

> If the nstat and netstat counters don't match, something is fishy.
> That nstat output is broken.
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/