RE: [load balancing] alteon session loss

From: Pérez Hernández, Angel Luis (
Date: Mon Nov 17 2003 - 12:56:21 EST

  • Next message: Alex Moore: "RE: [load balancing] alteon session loss"

    At least in our case, the connections come from test machines from our own network. No proxy, no hiding IP address ...

        Angel Luis Pérez Hernández
        Centro de Competencia Arquitectura Avanzadas



            De: Kenneth Thurman []
            Enviado el: lunes, 17 de noviembre de 2003 17:50
            Para: ''
            Asunto: RE: [load balancing] alteon session loss


               One possibility for this behavior is that the connections are coming from a Proxy server which is pipelining multiple client requests in one TCP session and is not cookie aware such as Microsoft's MS proxy version 2.0. The Alteon will only check the first GET or POST request in a TCP session after the initial handshake, so if another GET/POST comes in from a client on the same tcp session it will be sent to real server that the session was spliced to on the first GET/POST.

            If this is the case there is a workaround, you can change from cookie persistency to URL load balancing based on a cookie value, but you will have to setup the servers to supply a cookie with a unique static value that can be examined. The reason that this would work is that URL load balancing will examine all GET/PUTS and re-splice the connection in necessary.

            But this is only one thing that may be causing the problem you are seeing, examining a sniffer trace on the client side would go along way to finding out what is happening.


            Ken T.

            -----Original Message-----
            From: Alex Moore []
            Sent: Monday, November 17, 2003 6:22 AM
            Subject: RE: [load balancing] alteon session loss

            Thanks for the info Pete, this is how I understood it too.

            Although one key thing is that the client appears to be presenting the Alteon cookie, but being sent to the wrong, the server 3 logs the request showing it with the Alteon cookie for server 1...

            Alex - continuing the investigation... :)

            On Fri, 2003-11-14 at 16:42, Pete Tenereillo wrote:
    > Alex, There are a number of things that could cause that behavior.
    > Since you are using session (or as you say, "temporary") cookies (i.e.
    > you do not set an expires time), and the users start multiple windows
    > from the "Start" menu or icon instead of "File|New", the cookies will
    > not be sent on subsequent requests from that window. The reason - that
    > method of opening a new window causes the new browser instance to run
    > in a different memory space on the client so the cookies are not
    > shared (the fix is to use "permanent" cookies, i.e. set an expires
    > time, which forces the cookies to be stored on disk on the client and
    > shared between instances). Another possible issue - If you are using
    > domain name aliases (e.g. and the browser
    > will store the cookies independently for these. It's possible you hit
    > a bug too, though less likely. The list goes on. If you provide some
    > more details you may be able to get an answer here. A config and
    > traces would help.
    > Pete.

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