[THIN] Re: What happens when you overload a Citrix server?

  • From: "James Scanlon" <James.Scanlon@xxxxxxxxxxxxxxxx>
  • To: <thin@xxxxxxxxxxxxx>
  • Date: Wed, 3 Nov 2010 16:47:07 -0000

Do you have ICA keep alives enabled - just to see if that prevents the


From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On
Behalf Of Landin, Mark
Sent: 03 November 2010 16:13
To: thin@xxxxxxxxxxxxx
Subject: [THIN] What happens when you overload a Citrix server?

Running CPS 4.5 on Windows 2003 Standard, 32-bit, SP2. 4 GB RAM.


Our primary application is Microsoft Dynamics GP as a published
application. This has a memory footprint of 150-200MB per user, and we
currently are seeing 20-25 users per box (i.e., 5GB+ of memory


Recently our users have begun experiencing session disconnects,
especially when coming back from being idle (walked away from their
desk, turned to take a phone call, etc). We have no timeouts set on the
ICA sessions and sometimes connection is lost even if they turn away for
less than 5 minutes.


One theory is that the processes are dying because the servers are under
memory stress (which they are), and that Windows is killing these
processes to relieve the pressure. It may be killing the dynamics.exe
process itself, or the ODBC connection between the application and the
SQL server is being lost, which apparently causes the Dynamics GP
application to wet itself and die.


So, my question(s) is/are:

-          When Windows is under severe memory pressure, will it just
terminate processes? If so, how does it determine which ones?

-          When it does so, will there be anything logged in Event
Viewer? If not, how can one confirm that in fact Windows is killing
processed in order to reduce memory footprint? 


If this is in fact the root cause, of course we have some options, like:

-          build more servers (scale out)

-          build bigger servers (scale up). We may be able to do 64-bit,
but that will break new ground for us and I don't know how long that
will take us to do. Would going to 2003 32-bit Enterprise Edition, and
providing 8 or 16GB of RAM, help? Again, we are theorizing that the
server is running out of RAM resources, not necessarily running out of
kernel memory resources, so would throwing more RAM by way of Enterprise
edition going to help?


Thanks for the assistance.


This message and any attachments may be a confidential attorney-client
communication or otherwise be privileged and confidential. If you are
not the intended recipient, any review, distribution or copying of this
transmittal is prohibited. If you have received this transmittal in
error, please reply by e-mail and delete this message and all


C. Hoare & Co. is authorised and regulated by the Financial Services Authority 
with registration no. 122093.  The FSA’s address is 25, The North Colonnade, 
Canary Wharf, London E14 5HS.
Registered in England no. 240822.  Registered office 37 Fleet St, London, EC4P 

Confidentiality Disclaimer:
This message and attachments are confidential and may be privileged, and are 
sent for the personal attention of the addressee(s).  If you are not the 
intended addressee, any use, disclosure or copying of this document is 
unauthorised. Information transmitted by email may be intercepted, lost, 
destroyed, corrupted or delayed and as a result, C. Hoare & Co. do not accept 
responsibility for any errors or omissions in the contents of this message. If 
you would like to confirm the contents of this email, please request a hard 
copy version.

If the contents of this message are of a personal nature, the email will have 
been sent in a personal capacity and not on behalf of C. Hoare & Co.

C. Hoare & Co. may monitor all incoming and outgoing emails in line with 
current legislation. Although emails are screened for viruses, C. Hoare & Co. 
cannot guarantee that any transmissions will be virus free.

Other related posts: