Citrix questions concerning 350 "simultaneous" users

[gman10]

Hello All-

Well the snow hits the eastern seaboard once again.. Should've moved to Florida!! Anyway, my project manager has thrown me into the pit of conundrums once again.. here goes guys!

- Thers is a school district (4 buildings total) that need a Citrix solution for publishing one application.

-The app will be used by approximately 350 concurrent yet "simultaneous" users from 4 physical locations..
-ThI plan to use the latest Citrix Metaframe XP software on Windows 2000 servers in which Active Directory isn't setup across all buildings so I thought that publishing this app with the latest "Nfuse" product would be best since users aren't authenticating to a directory tree structure.

PROBLEM TO SOLVE: How many servers would I need to tell the district to purchase based on 350 users in need of this app "simultaneously".. It's a "Attendance Program" that -from what I'm told will be utilized across the span of 350 concurrent and simultaneous users. I would imagine it would have to be 4 to 5 decent PIII or IV processor, 1/2 gig of RAM, and what about licenses for Citrix? costly I'm sure..

Anyone care to take a stab at it?

I'll do my research but am looking for people who have been there before, in this type of scenario.. yeah, no Active Directory - bummer!

Enjoy the weather gang!

Gman

 

[terrywilson]

Sorry, never done it without AD before....didn't realise you could...

I wouldn't gamble a guess for hardware requirements before at least trying out the app on a test server; you need to know a few things - RAM used per user (If its all one app, something like TSCALE could get you a bit of mileage here), CPU utilisation per process, space required for data, etc.

Unfortunately its one of those how long is a piece of
string questions...

Other important points to consider will be how much data does the app pull back and forth; will your nw infrastructure support the amount of traffic you are moving; One of the weakpoints of citrix is printing, so consider how you will be taking care of that as well (steer away from autocreated for this many users). Heaps of questions all of which will want answering before you throw around any figures.

As far as alternatives to citrix go (Yes it is expensive, at least in NZ). There are alternatives (apparently), have a look here

http://www.brianmadden.com/reviews/

and check out his article "Server Based Computing Software Roundup"

 

[DDILL]

If you are not using Active Directory how do you plan to have the user(s) authenticate? Will they be able to use anonymous login to this? If so you could have the user login as guest to nfuse and access the application anonymously. Of course this is only if the Nfuse (web interface) is internal only and the app does not need windows authentication.
For scaling number of users per server you may want to look at products like T-scale, or my favorite Armtech but my opinion is if you are publishing one application and it is not some single threaded process that consumes a full cpu when one instance is run the performance tools will not be money well spent. The best way to determine concurrency is to load test. Build a server (recommend dual CPU with 1 to 2 GB of RAM) and simulate a minimum of 5 users. You should be able to get performance stats from that load to do the calculation for servers needed. remember to add 10% for failover. If one server goes down you do not want your users to suffer.