[THIN] KB: CTX106970 - How to Enable User Mode Stack Trace Database for IMA Service to Detect Memory Leaks
- From: "Jim Kenzig Kenzig.com" <jkenzig@xxxxxxxxx>
- To: thin@xxxxxxxxxxxxx
- Date: Sat, 2 Jul 2005 08:03:03 -0700 (PDT)
CTX106970 - How to Enable User Mode Stack Trace Database for IMA Service to
Detect Memory Leaks
This document was published at:
http://support.citrix.com/kb/entry.jspa?externalID=CTX106970
Document ID: CTX106970, Created on: Jul 1, 2005, Updated: Jul 2, 2005
Products: Citrix MetaFrame XP 1.0 for Microsoft Windows 2000, Citrix MetaFrame
XP 1.0 for Microsoft Windows 2003, Citrix Presentation Server 4.0 for Microsoft
Windows 2000, Citrix Presentation Server 4.0 for Microsoft Windows 2003, Citrix
MetaFrame Presentation Server 3.0 for Microsoft Windows 2000, Citrix MetaFrame
Presentation Server 3.0 for Microsoft Windows 2003
Symptoms
Users may experience IMA service leaking memory and heap expansion: ImaSrv.exe
process consumes more than 100 MB. Sometimes it can be even 500 MB or 1.5 GB.
Cause
Heap expansion (memory leak) results from some components not freeing
dynamically allocated heap memory. Over time it results in process growth in
memory, slow operation, and eventually application hang or crash.
Resolution
To detect the components responsible for memory leaks, the user should enable
an additional runtime diagnostic called user mode stack trace database. If this
diagnostic is enabled, an application dump should be generated manually when
the IMA service process has an unusual size.
First, you will probably need to download and install Debugging Tools for
Windows from Microsoft to use the gflags.exe utility:
http://www.microsoft.com/whdc/ddk/debugging/default.mspx
Use the following syntax to enable diagnostic:
gflags /i ImaSrv.exe +ust +htd
The command should display:
Current Registry Settings for ImaSrv.exe executable are: 00009000
ust - Create user mode stack trace database
htd - Enable heap tagging by DLL
Once you have the dump, the diagnostic should be disabled to avoid performance
degradation.
To disable the diagnostic, use the following command:
gflags /i ImaSrv.exe -ust -htd
This command should have the output:
Current Registry Settings for ImaSrv.exe executable are: 00000000
Another way is to use the GUI interface by launching gflags.exe:
Note: You need to restart the IMA service after enabling or disabling the
diagnostic.
To verify that gflags.exe was used correctly, Citrix Technical Support
personnel can open the dump in WinDbg.exe and run the command:
0:000> !gflag
Current NtGlobalFlag contents: 0x00009000
ust - Create user mode stack trace database
htd - Enable heap tagging by DLL
More Information
If you need the diagnostics enabled for another application, replace ImaSrv.exe
with your application name
Other related posts:
