Symptoms
When a published application opens Internet Explorer internally and if you click on any link in the embedded Internet Explorer, then a new window is opened. This issue does not exist when the application is opened using a published desktop. This issue exists only with Internet Explorer 8 and does not exist when using any earlier versions of Internet Explorer.
Background
Internet Explorer 8 introduces a new feature LCIE or Loosely-Coupled Internet Explorer. This feature decentralizes the Internet Explorer tabs in a single Internet Explorer session and prevents an unresponsive Internet Explorer Web page from crashing the entire application.
This feature has a disadvantage of causing Internet Explorer to potentially launch multiple sessions when an application opens Internet Explorer.
Resolution
Caution! This fix requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.
Open the registry editor on the computer and open the following registry key:
HKCUSoftwareMicrosoftInternet ExplorerMain – TabProcGrowth (string or dword)
Tab Process Growth: This registry key sets the rate at which Internet Explorer creates New Tab processes. There are two algorithms used by Internet Explorer.
- Context-based algorithm: By default, the context-based algorithm is used and the curve is chosen based on the amount of physical memory on the machine. In addition, the TabProcGrowth string registry value might be manually forced to have any of the following options:
small: Maximum 5 tab processes in a logon session, requires 15 tabs to get the third tab process.
medium: Maximum 9 tab processes in a logon session, requires 17 tabs to get the fifth tab process.
large: Maximum 16 tab processes in a logon session, requires 21 tabs to get the ninth tab process. - The Max-Number algorithm: This specifies the maximum number of tab processes that might be executed for a single isolation session for a single frame process at a specific mandatory integrity level (MIC). The following are the Relative values:
TabProcGrowth = 0: Tabs and frames run within the same process; frames are not unified across MIC levels.
TabProcGrowth = 1: All tabs for a given frame process run in a single tab process for a given MIC level.
Note: On Terminal Server, the default value is the integer 1.
TabProcGrowth > 1: Multiple tab processes are used to execute the tabs at a given MIC level for a single frame process. In general, new processes are created until the TabProcGrowth number is met, and then tabs are load balanced across the tab processes. Note that the frame process is no longer allowed to execute at low MIC. If this is attempted, the process exits.
You might select the Max-Number algorithm by specifying the registry value as an integer. The registry value might be a string value containing an integer such as 5 or a DWORD value containing an integer such as 5.
In general, you have to restart Internet Explorer to use a different Tab Process Growth value.
More Information
Refer to any of the following URLs for more information:
- http://blogs.msdn.com/b/ie/archive/2008/03/11/ie8-and-loosely-coupled-ie-lcie.aspx
- http://blogs.msdn.com/b/askie/archive/2009/03/09/opening-a-new-tab-may-launch-a-new-process-with-internet-explorer-8-0.aspx
