Date: Thu, 6 Nov 2008 15:30:49 +0300 From: pluknet <pluknet@gmail.com> To: "Peter Jeremy" <peterjeremy@optushome.com.au> Cc: FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: CARP performance tuning question. Message-ID: <a31046fc0811060430h50660363n7152ccd299fd4829@mail.gmail.com> In-Reply-To: <20081106104307.GC51239@server.vk2pj.dyndns.org> References: <a31046fc0811050540o527d315dvef1b35142f5caa29@mail.gmail.com> <20081106104307.GC51239@server.vk2pj.dyndns.org>
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2008/11/6 Peter Jeremy <peterjeremy@optushome.com.au>: > 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% idle >> PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND >> 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'? > Thanks for your answer and, please, ignore this premature mail. It would need a bit more analysis. -- wbr, pluknet
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