Date: Tue, 4 Oct 2011 17:47:22 -0700 From: Jeremy Chadwick <freebsd@jdc.parodius.com> To: Steven Hartland <killing@multiplay.co.uk> Cc: liv3d@multiplay.co.uk, freebsd-stable@freebsd.org Subject: Re: serious packet routing issue causing ntpd high load? Message-ID: <20111005004722.GA27935@icarus.home.lan> In-Reply-To: <41092663DF7A417D8A934A2840033412@multiplay.co.uk> References: <2740DA0E7C0F495BA00E6D4BC0FE8F37@multiplay.co.uk> <41092663DF7A417D8A934A2840033412@multiplay.co.uk>
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On Wed, Oct 05, 2011 at 01:27:18AM +0100, Steven Hartland wrote: > ----- Original Message ----- From: "Steven Hartland" > <killing@multiplay.co.uk> > .. > >This seems very much like the following pr which was fixed:- > >"Remove a bogusly introduced rtalloc_ign() in rev. 1.335/SVN 178029, > >generating an RTM_MISS for every IP packet forwarded making user space > >routing daemons unhappy":- > >http://www.freebsd.org/cgi/query-pr.cgi?pr=124540 > > > >The box is doing no routing, its fairly basic install with > >1 main IP on em0 + 1 alias + gw addres and 1 private ip on em1. > > > >Its running mysql and thats about it. > > > >Any ideas? > > This may also be causing significantly higher than expected > kernel time as well:- > 0 root 161 -8 0 0K 2560K - 1 44:26 23.88% kernel > > I've removed the alias on em0 and removed all addresses from em1 > leaving just 1 address on em1 + lo0 and still seeing the same > thing. I can't reproduce this on our 8.2-STABLE boxes. Specifically the one which is running ntpd that provides time syncing for local clients, as well as gets its source times from stratum 1/2 servers: $ uptime 5:45PM up 6 days, 2:13, 1 user, load averages: 0.00, 0.00, 0.00 $ uname -a FreeBSD XXXXXXXXXXXXXXX 8.2-STABLE FreeBSD 8.2-STABLE #0: Wed Sep 28 15:07:58 PDT 2011 root@XXXXXXXXXXXXXXX:/usr/obj/usr/src/sys/X7SBI_RELENG_8_amd64 amd64 1428 root 1 44 0 11900K 2860K select 0 0:17 0.00% /usr/sbin/ntpd -c /conf/ME/ntp.conf -p /var/run/ntpd.pid -f And "route -n monitor" shows no anomalies here. Maybe you should tcpdump to find out if there is a client or peer which is constantly pounding ntpd for some reason, or if ntpd is constantly nagging some peer? Not sure. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, US | | Making life hard for others since 1977. PGP 4BD6C0CB |
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