Re: High-volume HAProxy deployment tips?

From: Willy Tarreau <>
Date: Thu, 18 Dec 2008 22:50:37 +0100


On Wed, Dec 17, 2008 at 02:19:13PM -0800, David Rorex wrote:
> On Wed, Dec 17, 2008 at 1:48 PM, Daniel Gentleman <> wrote:
> > 2. Our proxy server is running FreeBSD 7.0 Stable. Are there any
> > recommended kernel or sysctl flags we can put in place to get optimal
> > network performance?

It's a bit hard to get tuning tips for FreeBSD unfortunately. That's a shame, because it's a powerful system when properly tuned. I remember having seen a few tips here on the list a while ago, but Google might be more helpful for that.

> > 3. Has anyone noticed performance or stability issues after a certain level
> > of bandwidth or number of concurrent connections?
> >
> The benchmarks on the haproxy home page show it filling a 10gbit link, so it
> would seem that it can handle high volumes.

Yes, it can run at 10gig on benchmarks. But you must be very prudent with benchmarks. Benchmarks are normally run to observer a product's behaviour under some circumstance, and figure out how to enhance it to provide better performance. I don't know anyone who's got 10gig of REAL traffic yet through haproxy, though we're working at it with some kind users with huge pipes. The highest REAL traffic rate on a production site I'm aware of is 3 Gbps. This already requires very deep system tuning down to the NICs' interrupt rates, because almost all of the CPU time is spent processing irqs and copying data to/from memory.

Right now I would say that achieving 2 Gbps is a reasonable goal for people who are comfortable with custom kernel builds and kernel tuning. 3 Gbps is achievable with a lot of care. Above, I wouldn't bet if you need to sustain more than a few thousands concurrent connections (though recent work tends to show that 7-8 Gbps seems to be a new reasonable goal). Maybe things are different with FreeBSD, I have no idea.

BTW, while we're speaking of less common OSes, has anyone ever tried on QNX ? I've already seen it provide wire-speed in the past, I don't know if it has followed hardware evolution.

Willy Received on 2008/12/18 22:50

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