That's a known fact, however I experienced Linux to perform the best in such worst case situations among several other Unices I tested, and NAPI certainly has brought some improvements in this area.Could you please be more specific on what exactly you're trying to achieve? Do you want to load balance an application whose average package size is 80 bytes? How many sustained connections per seconds do you have?Well, what I am trying to say is this: my experience is that under load with
small sized packets even standard routing/packet forwarding becomes lossy. If I
I'm afraid but I don't understand what you mean with the second part of your statement.put NAT and other nice netfilter features on top of such a situation things get a lot worse (obviously) - no comparison to building the "application" (e.g. cluster) with routing and hidden-patch (mainly because of its pure simplicity I guess).
Huh? Routing performance improvements? Routing is almost possible at wire speed. Some 60us delay per packet maybe (in case of load balancing decisions) but what do you want to improve?Don't get me wrong: I am pretty content with the hidden-patch and my setup without NAT. But I wanted to point to the direction of possible further routing performance improvement in 2.4.X tree. Is it correct that I can expect higher
I agree with you that netfilter NAT performance should and possibly can be impoved. And people are working on proof-of-concept improvements of NAPT in the Linux kernel including the netfilter team. But again, for me the hidden patch (http://www.ssi.bg/~ja/hidden-2.4.20pre10-1.diff) as it can be found does nothing to improve your situation.
I doubt this would help much but I haven't tested it and I do not see all consequences on the routing, the routing cache and the FIB policy of modifying HZ. I couldn't comment on that.data-rates (concerning small packets) if using higher HZ ?
Now that certainly is interesting, does he have any nice numbers to back this up? I'd be very interested. Also I've cc'd Jamal (I hope he will forgive me for that) who's working in this field since a couple of years now. Maybe he can comment on the HZ changes.Someone selling E3 cards told me he cannot manage loads like these (small packet stuff) with a stock kernel, and that you _at least_ have to increase HZ to get acceptable throughput results.
Best regards,
Roberto Nibali, ratz
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