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• 04-18-2008, 10:34 AM

  species5618 Joined on 11-14-2007, 12:01 AM UK Posts 14

  Desktop Heap and IIS Reply Contact Not so long ago I ran into the desktop heap problem with IIS 6 and unique user IDs for Worker process' http://support.microsoft.com/kb/831135 This was on a 32 bit machine with 4 G Ram, and it broke around 65 process's The KB article states "Note This issue occurs in both the 32-bit version of IIS and the 64-bit version of IIS." Can any one point me to a article or KB on: The relationship between "Desktop heap" , Physical Memory, Size of Desktop heap in 32 bit and 64 bit OS,  How does terminal service edition or citrix get around the desktop heap limitations I suppose what I am really asking is there anything I can do to get more unique process indeitities running without a shared desktop heap. Also does the desktop heap issue affect IIS7 Lee hampton-whitehead Http://siliconpizza.com | I’ll have a slice of that

  Tags: Desktop HeapIIS6

• 04-18-2008, 2:28 PM

  In reply to

  anilr Joined on 05-23-2006, 10:13 PM Redmond, WA Posts 1,090	Re: Desktop Heap and IIS Reply Contact This article talks about desktop heap (and linked articles at the end talk about changes in vista/ws08) Anil Ruia Senior Software Design Engineer IIS Core Server

• 04-21-2008, 8:38 AM

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  Rovastar Joined on 03-13-2008, 10:00 AM London, UK Posts 594

  Re: Desktop Heap and IIS Reply Contact Microsoft state a limit of about 60. Here explains more. http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/webapp/iis/appisoa.mspx " Number of Application Pools That Can Be Configured In the default configuration, using Network_Service as the application pool identity, you can create a large number of application pools without any difficulty. When you specify an identity for an application pool, it is given a set of resources, including a non-visible desktop. Interactive processes use desktops for dispatching events or messages, such as a mouse click, to Windows applications. In this context, only a few desktops are ever required by an application. For server applications, such as IIS, there is no interactive user; IIS and other COM applications running in a Single Threaded Apartment (STA) use the Windows message pump in a desktop to marshal data to COM components created within the process, and desktops are created even if the application uses no COM components. Microsoft tests show that when configuring more than 60 application pools with unique identities, a shared desktop should be used. This may be configured by setting the registry key HKLM\System\CurrentControlSet\Services\W3SVC\Parameters\UseSharedWPDesktop to 1. When this setting is enabled, application pools share a common desktop, thereby increasing scalability" And in related article read David Wang blog on this.  http://blogs.msdn.com/david.wang/archive/2006/01/25/Security_considerations_of_UseSharedWPDesktop_on_IIS6.aspx and here is some more techy details on the heaps including 32 and 64 bit sizes http://blogs.msdn.com/ntdebugging/archive/2007/07/05/desktop-heap-part-2.aspx  Most overused word in IT is 'should' as in 'That should work!?!'

• 04-21-2008, 12:38 PM

  In reply to

  anilr Joined on 05-23-2006, 10:13 PM Redmond, WA Posts 1,090	Re: Desktop Heap and IIS Reply Contact Note that using the UseSharedWPDesktop key is probably not necessary on x64 systems and on vista/ws08 x86 (or x64) systems due to the increase in address space available for session data and hence desktop heap. Anil Ruia Senior Software Design Engineer IIS Core Server