From owner-freebsd-hackers@FreeBSD.ORG Wed Oct 27 14:14:20 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8C54916A4CE for ; Wed, 27 Oct 2004 14:14:20 +0000 (GMT) Received: from ussenterprise.ufp.org (ussenterprise.ufp.org [208.185.30.210]) by mx1.FreeBSD.org (Postfix) with ESMTP id F337243D46 for ; Wed, 27 Oct 2004 14:14:19 +0000 (GMT) (envelope-from bicknell@ussenterprise.ufp.org) Received: from ussenterprise.ufp.org (bicknell@localhost [127.0.0.1]) by ussenterprise.ufp.org (8.12.9/8.12.9) with ESMTP id i9REEJaK036912 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 27 Oct 2004 10:14:19 -0400 (EDT) Received: (from bicknell@localhost) by ussenterprise.ufp.org (8.12.9/8.12.9/Submit) id i9REEJ9C036911 for freebsd-hackers@freebsd.org; Wed, 27 Oct 2004 10:14:19 -0400 (EDT) Date: Wed, 27 Oct 2004 10:14:19 -0400 From: Leo Bicknell To: freebsd-hackers@freebsd.org Message-ID: <20041027141419.GA36554@ussenterprise.ufp.org> Mail-Followup-To: freebsd-hackers@freebsd.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="IJpNTDwzlM2Ie8A6" Content-Disposition: inline Organization: United Federation of Planets X-PGP-Key: http://www.ufp.org/~bicknell/ Subject: Busy BIND + 5.2.1 = UDP Packet Loss X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Oct 2004 14:14:20 -0000 --IJpNTDwzlM2Ie8A6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable I recently upgraded a fairly busy nameserver to FreeBSD 5.2.1, and I'm seeing packet loss from time to time on the box. I've done some digging, and the box seems to be dropping UDP packets. Netstat output: udp: 177604011 datagrams received 0 with incomplete header 7 with bad data length field 2735233 with bad checksum 83753 with no checksum 205540 dropped due to no socket 1917 broadcast/multicast datagrams dropped due to no socket 10627437 dropped due to full socket buffers 0 not for hashed pcb 164033877 delivered 169793422 datagrams output The "dropped due to full socket buffers" seems to be the issue. I am also concerned by the number of packets with bad checksums, but I have no previous data point. I am seeing loss with DNS, but also with ping and given the few pauses in my ssh sessions with TCP as well. I don't see anything remarkable with the TCP or ICMP statistics. I don't think there's anything wrong in MBUF land, statistics here for reference: % netstat -m mbuf usage: GEN cache: 0/256 (in use/in pool) CPU #0 cache: 335/672 (in use/in pool) Total: 335/928 (in use/in pool) Mbuf cache high watermark: 512 Maximum possible: 51200 Allocated mbuf types: 291 mbufs allocated to data 14 mbufs allocated to ancillary data 16 mbufs allocated to fragment reassembly queue headers 14 mbufs allocated to socket names and addresses 1% of mbuf map consumed mbuf cluster usage: GEN cache: 0/152 (in use/in pool) CPU #0 cache: 289/400 (in use/in pool) Total: 289/552 (in use/in pool) Cluster cache high watermark: 128 Maximum possible: 25600 2% of cluster map consumed 1336 KBytes of wired memory reserved (49% in use) 0 requests for memory denied 0 requests for memory delayed 0 calls to protocol drain routines The only other thing I found of interest was some interrupt drops: % sysctl -a | grep drops net.inet.ip.intr_queue_drops: 13981 So, given the traffic profile (nameserver, heavy UDP) and the info here can someone help point me in the right direction? I'm not sure where to go from here? --=20 Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org --IJpNTDwzlM2Ie8A6 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFBf607Nh6mMG5yMTYRAqUsAJ9BMN6aEuXXWrJJc3+tXePO8O2J7wCaA5Ub Hu08eain/jiTlscA5i1XyUM= =A613 -----END PGP SIGNATURE----- --IJpNTDwzlM2Ie8A6--