Address pools and load balancing issues

Kostas Zorbadelos kzorba at
Mon Apr 3 08:48:24 UTC 2006

On Sun, Apr 02, 2006 at 05:49:42PM +0200, Max Laier wrote:
> On Sunday 02 April 2006 10:25, Kostas Zorbadelos wrote:
> > Ideally, I
> > would like to express all my pools as tables and have all the
> > different algorithms for load balancing available.
> The problem is what does bitmask or source-hash mean for a table?
> What do you  
> apply the bitmask to?  

I can understand that bitmask requires the use of a continuous network

> What do you hash to?  

On the other hand, I see no reason not to hash, or choose randomly
to/from a discrete set of addresses.

> The other problem is the 
> internal organization of tables that is optimized for lookups and doesn't 
> work as a list or array which is required for hashing.  

I will try my best to give a look at the actual code. I believe you
are telling me that the representation of tables is in a data
structure of some sort (a tree or something?) that makes it difficult
to hash or choose randomly. If this is the case, the situation could
be fixed (with a certain cost of course).  

> A sollution would be 
> to have real address lists, but I doubt that will happen any time soon.

Do you mean have data structures internally that represent
effectivelly address lists?

> As for a workaround sollution for you.  sticky-address works also without 
> states, provided you set a reasonable value for "set timeout source-track" as 
> described in pf.conf(5).  

Yes, I saw that, thanks very much for confirming, I believe this is
the way to go.

> Another option is to just make your webserver into 
> a continuous netbock via rdr/binat rules.  You should be able to map them 
> into a private netbock and can then apply source-hash load-balanceing to 
> that.  Of course there is overhead associated with that as well.  It really 
> depends on your usecase which is the most workable sollution.

Although this could provide a solution, I believe it is a non elegant
hack. Thanks for the suggestion though. 

> > Thanks in advance and congratulations to all the people involved in pf
> > for the great work.
> -- 
> /"\  Best regards,                      | mlaier at
> \ /  Max Laier                          | ICQ #67774661
>  X  | mlaier at EFnet
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Best regards,

  Kostas Zorbadelos
  m at il contact: kzorba (at)
  Out there in the darkness, out there in the night
  out there in the starlight, one soul burns brighter
  than a thousand suns.

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