Citrix Presentation Server - A little help?

[InfiniteNow]

Anyone here familiar with Citrix Presentation Server? Until this morning, I was not. I've spent much of today trying to learn as much as I can about it.

 

It has been proposed as a solution to an issue we have in training as pertains to training delivery in Asia and Europe. There is a concern that in our classroom sessions the bandwidth and network capacity for a few thousand of these users will be too low to successfully hit the server where the training is loaded. To complete the courses, however, the users must complete the exercises loaded on this server. (There are a few complexities and specifics that I cannot go into, but our options are pretty limited to resolve this network capacity issue).

 

So... one of our primary tech contacts suggested using Citrix Presentation Server. It seems this will reduce the need for bandwidth, and users in Asia and Europe would hit the Citrix server instead of the server where the training is loaded.

 

 

Can anyone help me understand:

 

1) Why the Citrix option would be advantageous,

 

2) What types of issues using Citrix might cause, and

 

3) How it manages to reduce the overall need for bandwidth (as opposed to just hitting the primary training server, where we anticipate bandwidth problems)?

 

 

I read that it has something to do with application virtualization, but I have no experience with that, and I need to know more about what is actually happening and why.

 

I've setup a meeting with our Citrix team next week, and I've been tasked with closing this issue and putting a solution in place before the holiday shutdown. I have learned a lot today on my own, but I really need know at a more detailed level how it works, what it's doing, and why it's going to help us (or not). Also, I need to know what types of questions to ask. I'll continue doing more research online, but you are a learned bunch, so I figured I'd ask you too.

 

 

Any comments, suggestions, or explanations of my uncertainties above are welcomed. Thanks.

[InfiniteNow]

I think part of my confusion was I was misrepresenting the problem.

 

The students will not need to hit the source server. The source server will publish a flash based simulation to a webpage, and the students will hit that webpage. The issue is getting the flash to load and run properly for the students due to the low network capaciity of some of our more rural sites. The suggestion was made that Citrix would help. Having done some more reading, it appears that Citrix strips much of the code and html and "hand shaking" stuff, and just sends the visual output (like screenshots) to the user.

 

Does this sound right?

 

 

I want to know my **** before I enter that meeting with the experts. I need to ask them the right questions before I come back to my team with a greenlight or a redlight on this proposed approach. My team is accountable for successful delivery, and we cannot let infrastructure issues stop us.

 

 

It's all about identifying the problem, surveying potential solutions, picking the best solution, then moving on to the next problem.

 

I just don't like it when I don't understand something, and I need to bring myself up to speed on Citrix before next week. Thx.

[LaurieAG]

Can anyone help me understand:

 

1) Why the Citrix option would be advantageous,

 

2) What types of issues using Citrix might cause, and

 

3) How it manages to reduce the overall need for bandwidth (as opposed to just hitting the primary training server, where we anticipate bandwidth problems)?

 

Hi Infi,

 

For 8 years I developed software for a company that used Citrix MetaFrame (DOS) and Citrix WinFrame on its servers.

 

Citrix is a THIN CLIENT as opposed to a THICK CLIENT.

 

A THICK CLIENT is just like how your normal network operates, the server just facilitates access to the components required by the software and sends all of the components, data and screens etc through the network to the workstation.

 

A THIN CLIENT is a system where the server does all of the processing for the applications running on it, and it only sends screen changes across the network instead of the whole lot (back and forth etc). Thin Client requires that you have enough memory on your server to support every user (i.e. win 98 required a minimum of 100MB per terminal) because the server is where the processing occurs, not the workstation. You can use Dumb Terminals for Thin Client access due to this.

 

While I'm not up on Citrix Presentation Server I would say that it's built as a part of their core Thin Client solutions on similar principles.

 

The main PRO is that network bandwidth is reduced massively (and application speed is increased) while the main CON is that your server needs quite a bit of memory to handle all the users.

 

Hope this helps.

[LaurieAG]

Having done some more reading, it appears that Citrix strips much of the code and html and "hand shaking" stuff, and just sends the visual output (like screenshots) to the user.

 

Does this sound right?

 

Hi Infi,

 

Yes.

 

Citrix WinFrame also blanks out any moving images like the one on the MSIE screen. The Citrix Presentation Server probably fixes this problem.

[InfiniteNow]

Citrix is a THIN CLIENT as opposed to a THICK CLIENT.

Thank you for putting it in such straight forward terms. I had learned so much new terminology yesterday on this (while concurrently doing all of my *normal* work stuff), that by last night... with tired eyes, I really didn't know my *** from my elbow anymore.

 

Thin client... Makes good sense.

 

 

...while the main CON is that your server needs quite a bit of memory to handle all the users.

I have a high degree of confidence that this particular issue will not be a problem. However, I thank you for bringing it up, as I can validate with our internal citrix group when I meet with them next week.

 

 

Thanks again! Simple terms help, but the tech pieces matter too. You managed to include both in your posts. ;)

 

 

:hyper:

 

 

 

Just to clarify, it might not even be the Presentation Server. They just said, "Citrix might help." :hyper:

[LaurieAG]

Just to clarify, it might not even be the Presentation Server. They just said, "Citrix might help." :rolleyes:

 

Hi InfinityNow,

 

I think there's a Citrix client included in XP.

 

The only other piece of advice for developing on a Citrix platform is that you must log all of the present users out via the management console when you want to update a multi user exe (or you will find it very frustrating, no matter how many times you copy the exe). The Citrix server holds most of the main (unchanging) program files in common memory for all the users accessing the files, to conserve memory.

[InfiniteNow]

Hi Laurie -

 

Thanks for the follow-up. I met with the team yesterday, and we will be using Citrix to support our training simulations in the regions where network capacity is *rough* to say the least. We'll put the application and client stuff on the Citrix server, and specific links will be programmed to each user (who will be assigned a login based on their authentication profiles).

 

I had an account setup for myself this morning, published a link which led to a simulation, and tested it. It worked fine, and precisely as we need.

 

I've now inquired if our team can create accounts for 5-10K users, and how many concurrent users the server can handle. It looks like it may be in the 250-500 user range, but I'll have to wait and see.

 

 

 

Looking back at the OP, I've learned a LOT about this concept and technology in less than a week. It was a good call, and a good meeting. Thank you for your help steering my searches in the right direction.

 

 

One problem down, approaching infinity to go. :rolleyes:

[LaurieAG]

I've now inquired if our team can create accounts for 5-10K users, and how many concurrent users the server can handle. It looks like it may be in the 250-500 user range, but I'll have to wait and see.

...

One problem down, approaching infinity to go. :rolleyes:

 

Hi InfinityNow,

 

When I started on the project (1997) my client had a dual Pentium II 200 server and later on moved up to a dual Pentium III 400 server. Normal load was about 13% (of one processor) for 16 network (100MB NIC) users and a couple of dial up users. While the dial up was a bit slower than direct network access, broadband access was very close to a local network users speed.

 

Dual or Quad processors will up the internal throughput quite a bit but the total number of users will have the most impact on the servers performance, particularly at the network I/O bottleneck.

 

With modern processors, heaps of memory and GB (or better) network interface cards you should be able to serve quite a few users (at a reasonable cost, hopefully).

 

Please tell me how many you eventually get when you finish testing.

[InfiniteNow]

Well, I sent the question last night and I had an answer this morning. The current server farm can easily handle more than 200 concurrent users, but if we go too far above 300, then I may need to seek budget to add a few more servers. Per adding up to 10K people to access it with a profile, no worries.

 

 

Bear in mind, I don't do the buying nor the implementation. I tell them, "Here's what we need you to do, and here's the date by which it needs to be done." They come back and say, "It will cost you THIS much." I go get approvals and say, "Here's your funds. Make it happen, and let me know when it's ready."

 

 

 

Just another brick in... the wall. :)