Question about round robin

[Kevin]

> -----Original Message-----
> From: no name [mailto:britneyfreek at googlemail.com]
> Sent: Friday, November 06, 2009 10:52 AM
> To: Kevin
> Cc: freebsd-pf at freebsd.org
> Subject: Re: Question about round robin
> 
> i am not quite sure but i assume pf does no availabililtty checks as
> responses from systems behind an address might take too long...
> 
> - regards
> 
> Am 06.11.2009 um 16:34 schrieb "Kevin" <k at kevinkevin.com>:
> 
> > Hello,
> >
> >
> >
> > I am curious about simple round robin load balancing w/ PF. I see
> > how simple
> > it is to setup within the FreeBSD configuration file, but have a
> > fairly
> > simple question.
> >
> > Does PF detect if one of the addresses in the "pool" is not
> > responsive? Or
> > does it just blindly send traffic to all the addresses in the pool
> > regardless? Is there some sort of heartbeat functionality or status
> > check
> > perhaps? Has anyone accomplished something along these lines? Load
> > balancing
> > would be pretty useless if I couldn't take a server out of the pool
> > without
> > having to re-configure PF every time.
> >
> >
> > Any comments are appreciated!
> >
> >
> > Thanks,
> >
> >
> > Kevin
> > www.stardothosting.com


I've searched the freebsd-* mailing list as well as gone through the handbook regarding load balancing w/ PF (http://www.openbsd.org/faq/pf/pools.html) and found no mention of any kind of inherent availability checks or anything along those lines. Have I missed something? 

Seems that all the options (bitmask, random, source-hash, round-robin) provide for different ways to distribute traffic to the servers, but if a server dies or becomes unresponsive it would compromise the pool in itself. Most other load balancing solutions such as LVS can be incorporated with keepalived to allow for status checking.

I would love to know anyone who may have implemented a solution like that with PF + round robin.


Thanks,

Kevin