Our IT dept are about to deploy virtualized apps using Citrix XenApp.
One of these apps will be Dynamics AX 4.0 SP2, a ERP client (which I develop on).
They have supposedly reached a roadblock because an external 'Dynamics AX Consultant' has told our IT Dept that Dynamics 4 will not work optimally on Citrix and will run very slow because it is not optimized for Citrix. We have it running in a Test environment now and seems ok. They have been told that the only 'solution' is to upgrade to Dynamics AX 2009 where supposedly this problem as been fixed. (not a small task for my team!)
When I heard about this, I was quite surprised. From my brief knowledge of Citrix, I thought it would be application independent.
How does the citrix app virtualization work, in that a particular app would work better than others on citrix?
Would the speed of the virtualized app not just depend on the resources/network connection the citrix server has?
FYI, Dynamics AX is a 3-tier client/server system, so the client will be accessing a AOS application server, which then accesses the database.
Please enlighten me 🙂
Best Answer
There are still application vendors today that will not commit to saying that their application will work properly under Citrix, or VMware. In some cases, they even know that there are active problems. ERP apps can be tough nuts to crack, because in a lot of cases, you're getting all the install and support through a VAR, so you might not have access to a vendor KB or support forums.
It's possible that there are known problems though - if their application does stupid things like a ton of small disk writes, it can cause performance problems on a multi-concurrent-desktop-user system like Citrix or TS, especially if you don't have things like a write-cache on your storage system. Some software, and I've seen ERP software like this, assumes that only one user will have all the system resources available as needed.
So, push them for evidence of the problem - under what conditions is performance impacted, do they have sizing guidelines, etc. It's possible that your install won't fall prey to what he's claiming is a known problem.
However, if it's a real problem, and your testbed isn't generating the production load (real number of concurrent users pulling order reports or doing end-of-month activities, real stress-tests), then you can't do a good job of proving him wrong, either.
In general yes, but as I said above, it's not just CPU, RAM, and LAN bandwidth. There's also things like disk IO, and weird Windows things like Session Desktop Heap and GDI counters, that a single-user system very rarely has problems with.