From owner-freebsd-net@FreeBSD.ORG  Fri Dec 11 10:29:33 2009
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 6C359106566B
	for <freebsd-net@freebsd.org>; Fri, 11 Dec 2009 10:29:33 +0000 (UTC)
	(envelope-from john@traktor.dnepro.net)
Received: from traktor.dnepro.net (roof1.dnepro.net [212.3.111.66])
	by mx1.freebsd.org (Postfix) with ESMTP id E0A2E8FC12
	for <freebsd-net@freebsd.org>; Fri, 11 Dec 2009 10:29:32 +0000 (UTC)
Received: from traktor.dnepro.net (localhost [127.0.0.1])
	by traktor.dnepro.net (8.14.3/8.14.3) with ESMTP id nBBATSBb050761
	for <freebsd-net@freebsd.org>; Fri, 11 Dec 2009 12:29:30 +0200 (EET)
	(envelope-from john@traktor.dnepro.net)
Received: (from john@localhost)
	by traktor.dnepro.net (8.14.3/8.14.3/Submit) id nBBATSYt050758
	for freebsd-net@freebsd.org; Fri, 11 Dec 2009 12:29:28 +0200 (EET)
	(envelope-from john)
Date: Fri, 11 Dec 2009 12:29:28 +0200
From: Eugene Perevyazko <john@dnepro.net>
To: freebsd-net@freebsd.org
Message-ID: <20091211102928.GA40831@traktor.dnepro.net>
Mail-Followup-To: freebsd-net@freebsd.org
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4.2.3i
Subject: How can I find the reason network writes fail with ENOMEM on 7.x?
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 11 Dec 2009 10:29:33 -0000


I'm getting network write failures on a host running 7.2-PRERELEASE
(I know, I should update it to STABLE, but I've heard of similar reports
on 7-S too)

  Failures are expressed for example in BIND
named[72084]: /usr/src/lib/bind/isc/../../../contrib/bind9/lib/isc/unix/socket.c:1567: unexpected error:
named[72084]: internal_send: 192.168.71.91#1049: Cannot allocate memory
named[72084]: client 192.168.71.91#1049: error sending response: out of memory

and on ssh session spontaneously breaking with "Write failed: Cannot allocate memory"

Frequency of those failures clearly correlates with network load for the host,
which is mainly doing dummynet and ng_nat.

How can I find what to tune in this case?

-- 
Eugene Perevyazko