On Sat, Sep 16, 2006 at 08:59:27PM +0200, Markus Wernig wrote:
> Hi everybody!
>
> I am looking at implementing a round-robin load-balanced group of
> servers behind an OBSD firewall.
>
> The pf commands would run along the lines
> [...]
> table <servers> persist file /etc/pf.serverlist
> rdr on $ext_if proto tcp from any to $virtual_ip port 80 \
> -> <servers> round-robin
> [...]
>
> Now the question is, what happens if one of the servers in
> /etc/pf.serverlist goes down? I suppose, each nth connection is still
> forwarded to it. Apparently, I need to do some sort of health check
> periodically (say, every 60 seconds) and remove the faulty server from
> <servers> and from /etc/pf.serverlist (in case the fw gets reloaded
> while the server is still down).
>
> Now just before I go and hack away at that health check crontab script:
> Is anybody aware if such a check mechanism already has been implemented,
> maybe in some other form?
I'm not aware of such a system, though I am sure some people will have
already scripted one.
User-level proxies might do what you want, though.
Joachim
