On Fri, 13 Oct 2000, Wojtek Zlobicki wrote:
> He seems to be talking about some kind of load balancing device like a Cisco
> Local Director or something from Foundry.
>
> What puzzles me is the next part
>
> > >Even "session" level stuff like cookies and whatnot can be handled by
> > >these switches, to make sure your session stays on the same server.
>
> I know this works partially with the Local Director. However, things like
> SSL do not work properly with such a scenario.
Actually it works quite nicely, foundry has some neat stuff. We use them
for wirecloset switches too. You can get 72 10/100 ports, redundant
power, dot1q, etc all for like $15k.......thats like 16GB backplane,
compared to 3Gb of a catalayst::
http://www.foundrynet.com/techdocs/SI/Foundry_ServerIron_url_switching.html
>
>
> ----- Original Message -----
> From: "Priscilla Oppenheimer" <[EMAIL PROTECTED]>
> To: "Brian" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> Sent: Friday, October 13, 2000 1:54 PM
> Subject: Re: High Availability. (Maybe OT)
>
>
> > Who makes Layer 4 switches such as what you're talking about, Brian? Sorry
> > if it's a dumb question.
> >
> > I'm helping a customer who has a setup similar to what you describe, I
> > think. The customer is reluctant (unable?) to give me all the details,
> even
> > though I'm helping him troubleshoot some problems that are probably
> > related. (Layer 8, politics, will get you every time!)
> >
> > Thank-you for your help.
> >
> > Priscilla
> >
> >
> > At 08:30 AM 10/13/00, Brian wrote:
> > >Using Server Load Balancing on switches. Then between the switches you
> > >run a hot standby protocol. For example:
> > >
> > >The ip the clients use for the server would really be a "virtual" ip
> > >address, which is actually bound to the layer4 switch. The layer 4
> switch
> > >receives requests for the application (lets say port 80) and then load
> > >balances accross a server farm using a hash table. If servers
> die......it
> > >can handle this, because it does health checks to the servers. If the
> > >switch dies, then hot standby kicks in and another switch is activated.
> > >
> > >Even "session" level stuff like cookies and whatnot can be handled by
> > >these switches, to make sure your session stays on the same server.
> > >
> > >Other applications like databases etc, have similar scenerios. Normally
> > >in the above scenerio, you backend all the servers off a single file
> > >server so that the data is the same on all servers (NFS). This file
> > >server would be a high reliable server such as a NetApp
> > >
> > > >
> > >
> > > >
> > > > Problem, maintaing the same layer 3 address accross both switches in
> > > > the advent that one link should fail, the server maintains
> > > > reachability.
> > >
> > >
> > >
> > > >
> > > > Giving that in this case I would be talking about a solaris system, I
> > > > have thought about using simple scripts to watch for the interface to
> > > > go down and reconfigure. I am curious if anyone knows of any
> > > > hardware/software solutions for doing this? I am guessing that I am
> > > > not the first person to ask for something like this.
> > >
> > >Brian
> > >
> > >
> > > >
> > > > -- Kevin
> > > >
> > >
> > >-----------------------------------------------
> > >Brian Feeny, CCNP, CCDP [EMAIL PROTECTED]
> > >Network Administrator
> > >ShreveNet Inc. (ASN 11881)
> > >
> > >_________________________________
> > >FAQ, list archives, and subscription info:
> > >http://www.groupstudy.com/list/cisco.html
> > >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
> >
> >
> > ________________________
> >
> > Priscilla Oppenheimer
> > http://www.priscilla.com
> >
> > _________________________________
> > FAQ, list archives, and subscription info:
> http://www.groupstudy.com/list/cisco.html
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
-----------------------------------------------
Brian Feeny, CCNP, CCDP [EMAIL PROTECTED]
Network Administrator
ShreveNet Inc. (ASN 11881)
_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
