Thanks for all the assistance so far.

Over the weekend I adjusted by configuration back to its original state, with a single service and 2 backends specified for both http and https. All web traffic continues to go to a single web server (10.0.0.2) when Session with Type IP is defined.

Relevant portions of my configuration are below, I've been using the listenHTTP service on port 2080 to confirm that requests do get forwarded to both servers when Session is not defined.
Currently I'm running version 2.0 on debian. (I have built 2.4.3, however I encounter a separate problem with that version.)

ListenHTTP
        Address 205.207.162.162
        Port    80

        ## allow PUT and DELETE also (by default only GET, POST and HEAD)?:
#       xHTTP           0
#       AddHeader "X-Forwarded-Proto: http"

        Service
                BackEnd
                        Address 10.0.0.2
                        Port    80
                End
                BackEnd
                        Address 10.0.0.4
                        Port    80
                End
                Session
                        Type IP
                        TTL 300
                End
        End
End

ListenHTTPS
        Address 205.207.162.162
        Port 443

        Cert "/usr/local/ssl/crt/public.pem"
        VerifyList "/usr/local/ssl/crt/intermediate.crt"

        AddHeader "X-Forwarded-Proto: https"

        Service
                BackEnd
                        Address 10.0.0.2
                        Port 80
                End
                BackEnd
                        Address 10.0.0.4
                        Port 80
                End
                Session
                        Type IP
                        TTL 300
                End
        End
End

#
#temporary setup for load balance testing
#
ListenHTTP
        Address 205.207.162.162
        Port    2080

        ## allow PUT and DELETE also (by default only GET, POST and HEAD)?:
#       xHTTP           0
#       Cert "/usr/local/ssl/crt/public.pem"
#       AddHeader "X-Forwarded-Proto: https"

        Service
                BackEnd
                        Address 10.0.0.2
                        Port    80
                End
                BackEnd
                        Address 10.0.0.4
                        Port    80
                End
        End
End

On Wed, Oct 1, 2008 at 11:48 AM, Robert Segall <roseg@apsis.ch> wrote:

On Tue, 2008-09-30 at 16:06 -0400, Cam Roberts wrote:
> Hi,
> I've configured pound with two BackEnds and Session Type IP, TTL 300.
>
> However all the load goes to one of the back end servers, I never see an
> apache connection on the other until the "primary" goes down. I'm not using
> Emergency, and if I comment out the Session block the load is balanced
> evenly between the two servers.
>
>
> Relevant portion of my pound.cfg:
>
> Service
> BackEnd
> Address 10.0.0.2
> Port 80
> End
> Session
> Type IP
> TTL 300
> End
> End
> Service
> BackEnd
> Address 10.0.0.4
> Port 80
> End
> Session
> Type IP
> TTL 300
> End
> End
>
>
> Originally I had:
>
> Service
> Session
> Type IP
> TTL 300
> End
> BackEnd
> Address 10.0.0.2
> Port 80
> End
> BackEnd
> Address 10.0.0.4
> Port 80
> End
> End
>
> The behaviour seems to be identical with both of the above configurations,
> it doesn't do any load balancing when Session is declared.
>
> >From my understanding of the manpage load should still be balanced when
> session handling is used, individual users will be bound to a single server
> but it should alternate with each new connection. Am I misunderstanding
> session handling?

Your current configuration is guaranteed not to work - you have defined
a "catch-all" service, so all the traffic goes there.

Your original configuration (assuming this is all you have in the file)
should work. Did you by any chance test it from a single client? Does it
work without session?

Finally, if one of the back-ends is not available, Pound will send all
the traffic to the other one. Check your logs and/or use poundctl.
--
Robert Segall
Apsis GmbH
Postfach, Uetikon am See, CH-8707
Tel: +41-44-920 4904

--
To unsubscribe send an email with subject unsubscribe to pound@apsis.ch.
Please contact roseg@apsis.ch for questions.

--
Thanks,
--Cameron Roberts