Why has the Citrix "Hotfix Rollup Pack 4" caused problems to the ICA clients ?

Hi and thanks for your post.

We haven't yet done this and wanted to try some other troubleshooting before we done this as I though that other users may have had the same problem

You may have a session graphics issue:
http://support.citrix.com/article/CTX114497

Rolling off HRP04 would be a good test as well but I would try to work through the problem first.  Make sure you have enough session memory and free system memory though.  

Hi and thanks also for your post,

We decided to remove the roll-up and this solved the problem for now.  Strangely when we upgraded some of the clients to v11 of the XenApp plugin this removed the issue but as there are over 70 users it wasn't possible to do this.

In terms of the memory on the Citrix server it has 64GB available to users and never uses anywhere near this amount.

I am talking about the amount of memory dedicated to each session, not the overall system memory, that was the last thing to check.  Just because you have 64GB available doesn't tell me anything about your kernel vs user memory, heap space, etc...Especially session graphics.  I would suggest reading my link, as a Citrix admin for the last 8 years I have not ever tuned the session graphics until calling an issue into Citrix support and it ended up fixing more than one problem I have had for years.  The default setting is not enough for all scenarios.  
Specifically, I am willing to bet a new feature was implemented in R04 and that is what you are experiencing.  Upgrading the local client makes the system happier but you may have a simple underconfiguration issue with the default setting.  This controls the memory allocated per user so the abundance of memory is all the more reason to look into what I am pointing out.  

Hi again,

I did see this when looking into an unrelated issue a while back and was slightly bamboozled by all the calculations etc.  I am fine with the Registry entries but don't want to make things worse.

The system is also 64-bit Windows so i'm not sure if that makes a difference.

Thanks again for your help

Well, 64 bit does free the system to manage memory much better.  Here is the calculation you can use to tune session graphics:

X: monitor width
Y: monitor height
Z: color depth (1 for 8-bit, 2 for 16-bit, 3 for 24-bit)
A: quantity of monitors

X*Y*Z*A*2=byes of RAM to allocate

for example, my screens run 1440x900 and I have 2 of them.  You want to allocate as much memory for a disconnected session as a connected one so that is where the extra 2 comes into play at the end.  

ex. 1440*900*3*2*2=15,552,000 (about 15MB)

for a scenario with 1024x768, 16 bit color on the session, 2 monitors:
1024*768*2*2*2=4,718,592 (about 5MB)

Here is the right article: http://support.citrix.com/article/CTX115637
The other one is ok as well but this one goes into more detail.  This is something you should have a test server to try out though, unless you are very comfortable with your server and its registry.  Like I said though, it was worth it for me.  I don't have RAM issues after doing this adjustment (so I am fairly confident I didn't hurt anything) and two different graphics issues went away.  
I was having a little block of chunky graphics sticking to my seamless sessions, this one is no longer happening.  I was also unable to drag seamless windows to my second screen.  One little registry tweak and life is better.  

On a side note, I am seeing more issues with client-server versioning then I have ever seen before.  Nearly all of my users running on XenApp5.0 systems need the 11.x client.  Some work fine for quite a bit but then we have been starting to see issues crop up.  I would not be suprised to hear you need the 11.x for users running on PS4.5HRP04.  PS4.5HRP03 is the same code base as XA5.0 RTM.  

Hi again,

Thanks very much for explaining this to me.  I'm at home just now but will give it a go in the morning and let you know how I get on.

Thanks again

Hi again,

I did the calculation to figure out how much memory we would require and this was:

1024 x 768 x 3 x 2 = 4,718,592 (which is obviously 4 MB)

I went into the registry to change the setting and it was already set at 8MB (I have attached this as a JPEG).  Should I be increasing this even further to try and resolve the issue we are having ?

Sorry for keeping on about this but I want to be 100% sure before I make the changes.

If you are already at 8MB you could bump it up just to see if it helps but it is less likely to be the problem.  Does the problem exist if your users run at a fixed window size instead of seamless?  

Hi,

It's is hard to say as I removed the roll up but the users are running with a 1024 x 768 without fault.  I think I will try to double this up to 16 MB and see if it makes a difference.

Thanks for all your help

No problem, you can always call Ctx support if you have $400 burning a hole in your pocket...

There is a hard coded limit of 8MB and you cannot go over that.  That is a Windows Server 2003 limit.  That will change with Server 2008 R2 and its support of up to 16 displays.  To allow for that, the session limit is going from 8MB to 4GB!!!

Server 2008's default is 32MB and can be expanded to 64MB.
Server 2003's default is 5MB and can be expanded to 8MB.

http://support.citrix.com/proddocs/index.jsp?topic=/xenapp/ps-install-migrate-mixed-graphics-memory.html

Hmm, a Citrix tech had me boost this up on a 2003 box, strange.  Thanks for the link.  

So will I ber able to go above the 8MB or will that have disastrous effects ?

I don't think you can go above the 8MB in x86.  You might be able to go higher in x64.  Try it and see what happens.

Ok thanks Carl,

I'll give it a try and let you know how I get on.

Thanks again for your help

http://support.citrix.com/article/ctx115637

Session Graphics Memory

When working with multi-monitor ICA sessions, it is very important to calculate the amount of ICA session graphics required. This is the memory allocated to each session for its graphics data and it is set to the default of 5120 bytes and limited to 8192 bytes in the Access Management Console.

We are experiencing a very similar issue with Hotfix Rollup 4.  Upgrading the workstation client to Xenapp 11.0, the problem goes away.  This is great for Windows XP and Vista however, we use several different brands of thin clients.  The CE versions do not have version 11 of the client yet.  Has anyone found a workaround yet?

A lot of people are removing HRP4 and rolling back to HRP3.