Re: High-volume HAProxy deployment tips?

From: Willy Tarreau <>
Date: Thu, 18 Dec 2008 23:27:53 +0100

Hi Piotr,

On Thu, Dec 18, 2008 at 11:13:22PM +0100, Piotr Rybicki wrote:
> Daniel Gentleman pisze:
> > 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?
> Check this list's archives.
> I believe there is a 'connection reuse problem' on FreeBSD. It's
> described somewere on this list (also by me). It's TCP/IP stack
> implementation so damn RFC compatibile ;-(. When i have some time, I
> will try to implement my solution (try to conect 3 times, if that fails
> - exit with an error). I that would be acceptable for Willy, I'll send
> my patch.

you once told me about this idea, but I failed to understand the advantage over the simple "retries" parameter which is already implemented.

> I'm not sure about accept filters functionality patch. It;s FreeBSD
> specific. How to deal with config file (enabling/disabling). Willy, any
> sugestions?

I'm not aware at all about "accept filters", what does it do, and what is it useful for ?

> There is also room for some improvements on this platform (to implement
> acceptfilters for example).
> If You happen to run pf on the boxes, be sure you will not suffer from
> max states limit. U can raise default limit and deploy adaptive removal
> (see pf manual).
> Also U can increase number of mbuf clusters (without this U can lock
> down net connectivity to the box due to lack of mbuf clusters, when
> having a lot of slow clients. Nasty thing).

Yes, I remember that name (mbuf clusters), it's the one FreeBSD users always speak about when they're targetting high performance.

> Also send/receive buffers for interface and for TCP can be raised.
> >
> > 3. Has anyone noticed performance or stability issues after a certain
> > level of bandwidth or number of concurrent connections?
> Yes, see below and search archives.
> Best regards.
> Piotr Rybicki

Willy Received on 2008/12/18 23:27

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