Scalability differences between iNotes 8.5.2 in IE8 and IE6 on Citrix XenApp

Why can't I get the same scalability with iNotes 8.5.2 Internet Explorer 8 on XenApp 5.0 as I did with Internet Explorer 6 in XenApp 5.0

Through exhaustive testing we have found that when Lotus iNotes in XenApp 5.0 is accessed with Internet Explorer 8 for an extended period of time without closing the browser there is a significant build up in memory usage. This is especially important for enterprise customers who enable users to access iNotes through Citrix virtualization technology.

For example:
Citrix iNotes version 8.5.2 implemented on a 4GB Windows Server 2003 machine can scale to a maximum of 27 concurrent users for a 5-day work week before the server's memory is exhausted. Users must be logged off and their browsers restarted to reclaim available memory resources.


Whereas by using Internet Explorer 6 the same configuration can cope with 38 users before the server memory becomes depleted by the end of the work week.


What can be done?
Microsoft has advised there are a number of settings that can be changed to help with memory usage while using Internet Explorer 8.

1. Restrict spawning of new processes:
In the registry navigate to...
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
Create a DWORD TabProcGrowth and value is 0
This change can also be made using Group Policy Objects.

2. Turn off all add-ons and third-party extensions

3. Follow the advice contained in this Microsoft Knowledge base article:

"A memory leak occurs when the InnerHTML property of an element is updated repeatedly in Internet Explorer 8" (Article ID: 975623)

4. Advise users to ensure they close down their Internet Explorer Citrix session at the end of the day.

If after these actions you are still experiencing memory issues you may wish to consider downgrading the browser to Internet Explorer 6, with which the memory usage is considerably reduced.