On Tue, 10 Jun 2003, Jamal Hadi wrote: > I thought you were saying those were _not_ real world traffic patterns. I'm saying the tests that you and Rob did in the past did not reflect real-world use of Linux as a core router (i.e. small routing table and not many different traffic flows). The tests he posted yesterday are a big step forward. > Typically, real world is less intense than the lab. Ex: noone sends > 100Mbps at 64 byte packet size. Typical packet is around 500 bytes > average. If linux can handle that forwarding capacity, it should easily > be doing close to Gige real world capacity. No, it needs to work in the worst case. If some script kiddie can peg my CPU with a synflood then there's still a problem. > > Most of the people I know that would actually see 50kpps > > in the real world don't have the time to apply various patches and run a > > Now thats one big dilema, isnt it? Do you think i have time? Let me > assure you that I dont get paid by anybody to do any of this stuff. Sure I realize that. The problem I've seen occur is that Linux developers with big egos say "linux can route as well as a cisco 3640", or "linux routing is beats BSD any day". Then guys like me decide to give it a try, not realizing we're walking into a tarpit. If I had been told in the first place that running linux as a high-throughput router in a service provider environment was an unknown, things would have been different. > I have spent many hours investigating peoples problems sshing to their > machines only to find out they didnt follow instructions. After the > 10th person doing the same thing, what do you expect my reaction to be? Take 15 minutes and write a web page with the magic settings required to make things work. > > Yup, still a duron 750 on an Asus mobo (Via chipset). Running Zebra > > 0.93b. If the ideas you're referring to are changing the zebra source to > > arp the next-nops, then no, I haven't tried it (and am not likely to any > > time soon). > > > > I think you may be suffering from the "too low" traffic NAPI syndrome. > Under low traffic (1-2 Mbps) on lower end machines NAPI will consume > more CPU because of an extra PCI operation per packet that is performed. No, as I said I'm moving ~30mbps and ~10kpps in and out of 2 3c905cx cards. > As for the zebra thing, if you post my message to the Zebra list i am sure > someone will be excited enough to do it. I need a few hours to do it > but like you i dont have much time. The last time I looked at the zebra list things seemed pretty dead. Most of the new work is now happening on the commercial zebra development. > > > Well, heres a good example: With NAPI, have your sessions been dropped? > > Yup, twice in the last 2 weeks. > > > > I have seen NAPI slow down throughput because of an intensive user space > app. This is a router with just zebra (zebra, ospfd, bgpd) running. > > I had joined the vortex list last fall looking for some tips and that > > didn't help much (other than telling me that the 3com wasn't the best > > choice). I've since bought a couple tg3 and a bunch of e1000 cards that > > I'm planning to put into production. > > yes, move to the giges then lets talk again. I think your main problem is > that 3com NAPI is not well supported. Lennert disappeared right after he > released the patch and noone else has the interest of maintaining it. Yes, and it would be nice if you mentioned in your NAPI docs that people should use a tulip, tg3, or e1000 if they want it to work well. In making your sales pitches for NAPI you made it sound like any high-performance card should do fine (i.e. anything but a Realtek). > > Rob's test results seem to show that even if I replace my 3c905cx cards > > with e1000's I'll still get killed with a 50kpps synflood with my current > > CPU. > > where are you getting the 50Kpps data from? I see him talkking of > input rate of no less than 200Kpps. On his first graph, for 50k new incoming dst/sec throughput looks to be ~175kpps. And he's running a 1.8Ghz Xenon vs my 750Mhz Duron. > > used a second Linux box for redundancy. If the BSD boxes turn out to have > > twice the performance of the linux boxes, it may be better for me to dump > > linux for routing altogether. :-( > > > > This is why you dont get very positivre reaction. You use religious > scripture and you expect that people will help prove you are wrong. You don't seem to get it. There's at least a dozen things more important to me than seeing Linux routing performance compete with Cisco and BSD. I'm annoyed that people like you have told me linux is up to the task, and then when it's not I'm left SOL. I thought I was talking to competent techies, but now I see most of the techies were also Linux evangelists. Now that people like Rob and Dave are taking a hard look at it I think it's worth my while to ante up for a couple more rounds. I still fell like a sucker that should have walked away from the table a long time ago though. Jim Mercer and Marc Ackley at 151.net/tht.net told me they tried Linux/Zebra and gave up (and went with 7206vxr routers). And they're very pro-unix (still do all their netflow collection and billing on Unix). They're not likely to go back and give Linux another try. If the linux evangelists had just said Linux would be ready for core routing in a year (or whatever) instead, I think network operators would look at it more seriously rather than they joke that they see it as now. -Ralph - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
