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?
thx /markus
