Date: Thu, 6 Nov 2008 21:43:07 +1100 From: Peter Jeremy <peterjeremy@optushome.com.au> To: pluknet <pluknet@gmail.com> Cc: FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: CARP performance tuning question. Message-ID: <20081106104307.GC51239@server.vk2pj.dyndns.org> In-Reply-To: <a31046fc0811050540o527d315dvef1b35142f5caa29@mail.gmail.com> References: <a31046fc0811050540o527d315dvef1b35142f5caa29@mail.gmail.com>
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--/Uq4LBwYP4y1W6pO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Whilst I don't doubt that you have a problem, your comments don't correlate particularly well with the data you have provided and this makes it difficult to immediately suggest a solution. On 2008-Nov-05 16:40:32 +0300, pluknet <pluknet@gmail.com> wrote: >AT work we use device carp(4) under high load: carp(4) is solely a failover mechanism. It either generates or receives somewhat under 1pps per carp interface and the state it maintains is basically 'master' or 'backup'. I suspect the 'load' is being caused by pf(4), possibly in conjunction with pfsync(4). >The problem is that the server experiences a bad interactivity (from >70k states and very bad from 120-150k) >i.e. when a network workload (and interrupts count) begin to increase. > >>From top(1): >CPU states: 0.0% user, 0.0% nice, 0.4% system, 76.3% interrupt, 23.3% i= dle > PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMM= AND > 13 root 1 -44 -163 0K 8K WAIT 407:43 57.86% swi1:= net I agree that swi1 is using a significant amount of CPU but top is still reporting >23% idle so you shouldn't be getting poor interactive performance. >ATM pfctl -s info shows such numbers: > >State Table Total Rate > current entries 153972 > searches 6052078938 4800.8/s > inserts 120373545 95.5/s > removals 120219573 95.4/s That shows the load on pf(4) but doesn't really reflect what the system is doing as a whole. >It works currently under UP, but could be rebuilt to work under SMP >(Xeon 5130) if that helps. Unfortunately, I don't know if this will help or not because I'm not sure what bottleneck you are hitting. >Can someone give hints to decrease interrupt count and to help with >the server stability at all? Well, you haven't actually reported what the interrupt count or what instability you are seeing so this is a bit difficult. Can you please provide some more information: - output from 'uname -a' - output from 'vmstat -i; sleep 10; vmstat -i' under load - output from 'netstat -i' - 10-15 seconds of output from 'netstat -i 1' under load - What is the box doing? Is it a straight filtering router? Does it handle NAT? Is it running apps itself (eg web, ftp, mail)? - What speed are the interface(s) running at? - What instability problems are you seeing? - Please provide more details on what you mean by 'bad interactivity'. - How complex is your pf ruleset? How many rules? Anything unusual? - What scheduler are you using? - What is the full output of 'pfctl -s info'? --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --/Uq4LBwYP4y1W6pO Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkkSyjsACgkQ/opHv/APuIdoiQCgsTHYbDRYx+VnitKkbpy1OsmJ TEoAn0ZxKbz0Hy2BRiBTbVjzjEVVJD6G =Ef3M -----END PGP SIGNATURE----- --/Uq4LBwYP4y1W6pO--
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