Memory Leak

[Peter]

I am using VS2008.

I have a Windows Service application which creates Crystal Reports. This is
a multi theaded application which can run several reports at one time.
My problem - there is a memory leak someplace. I can not detect the memory
leak by running several reports by hand, but when I run tha app as a
servrice and process few hundred reports there is significant memory leak.
The application can consume over 1GB of memory where it should not go over
200 mb. I have few other applications that use Crystal Reports and those
applications do not have memory leak, the big difference is those
applications are single threaded.

My question is are there any free tools I can use to find the memory leak?

I have tried http://www.softprodigy.com but I could not get it to work it
just locks up.

Thank You
Peter

[Cor Ligthert[MVP]]

Peter,

Always the first questions on Memory Leaks in the dotnet newsgroup

How do you know that there is a Memory Leak?

Cor

"Peter" <cz****@nospam. nospamschreef in bericht
news:OS******** ******@TK2MSFTN GP04.phx.gbl...

>I am using VS2008.

I have a Windows Service application which creates Crystal Reports. This
is a multi theaded application which can run several reports at one time.
My problem - there is a memory leak someplace. I can not detect the memory
leak by running several reports by hand, but when I run tha app as a
servrice and process few hundred reports there is significant memory leak.
The application can consume over 1GB of memory where it should not go over
200 mb. I have few other applications that use Crystal Reports and those
applications do not have memory leak, the big difference is those
applications are single threaded.

My question is are there any free tools I can use to find the memory leak?

I have tried http://www.softprodigy.com but I could not get it to work it
just locks up.

Thank You
Peter

[Jeffrey Tan[MSFT]]

Hi Peter ,

Regarding .Net memory leak issue, an important step is determing if it is a
managed leak or unmanaged memory leak.

Can you tell me what memory counter do you get "over 1G memory" result?
Windows has a lot of memory counters which may cause fake memory leak
conclusions. Basically, we should monitor "Process/Private Bytes"(or "VM
Size" column in task manager.) counter to determine memory leak. Note: we
should not use the "Mem Usage" column in task manager which is misleading.
I highly recommend you to download Process Explorer tool from the link
below since it is more powerful tool than task manager:
http://technet.microsoft.com/en-us/s.../bb896653.aspx

Once the "Private Bytes" is keeping increasing without decrease, it means
that the application is leaking memory. Now, you can monitor the ".Net CLR
Memory/# Bytes in all Heaps" counter. If the "Private Bytes" increases
while the ".Net CLR Memory" is stable, it indicates an unmanaged memory
leak. Otherwise, it basically means a managed memory leak. The article
below talks more information:
"I have a memory leak!!! What do i do? (defining the "where")"
http://blogs.msdn.com/tess/archive/2...leak-what-do-i
-do-defining-the-where.aspx

I will wait for your further feedback to determine if it is a managed or
unmanaged leak since they need totally different approach for
troubleshooting . Thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support

Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

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Engineer within 1 business day is acceptable. Please note that each follow
up response may take approximately 2 business days as the support
professional working with you may need further investigation to reach the
most efficient resolution. The offering is not appropriate for situations
that require urgent, real-time or phone-based interactions or complex
project analysis and dump analysis issues. Issues of this nature are best
handled working with a dedicated Microsoft Support Engineer by contacting
Microsoft Customer Support Services (CSS) at
http://msdn.microsoft.com/subscripti...t/default.aspx.
=============== =============== =============== =====
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[Peter]

"Cor Ligthert[MVP]" <no************ @planet.nlwrote in message
news:19******** *************** ***********@mic rosoft.com...

Peter,

Always the first questions on Memory Leaks in the dotnet newsgroup

How do you know that there is a Memory Leak?

Cor

"Peter" <cz****@nospam. nospamschreef in bericht
news:OS******** ******@TK2MSFTN GP04.phx.gbl...

>>I am using VS2008.

I have a Windows Service application which creates Crystal Reports. This
is a multi theaded application which can run several reports at one time.
My problem - there is a memory leak someplace. I can not detect the
memory leak by running several reports by hand, but when I run tha app as
a servrice and process few hundred reports there is significant memory
leak. The application can consume over 1GB of memory where it should not
go over 200 mb. I have few other applications that use Crystal Reports
and those applications do not have memory leak, the big difference is
those applications are single threaded.

My question is are there any free tools I can use to find the memory
leak?

I have tried http://www.softprodigy.com but I could not get it to work it
just locks up.

Thank You
Peter

I do not know if it's the memory leak - that's what I am trying to find out.

The reason I am starting with this assumption is because when I look at the
"Mem Usage" in the Windows Task Manager the memory keeps growing and never
ever goes down and eventually the system goes to a craw until I restart the
application. Plus my other simullar applications when they run the "Mem
Usage" goes up and down and eventually goes back to the almost original
starting number when the applications is not processing anything.

[Peter]

I get "over 1G" on both "Mem Usage" and "VM Size", the VM Size is slightly
lower but it's consistant with "Mem Usage" so in this case "at least it
looks like Mem Usage is just as reliable"

I have also downlaoded the Process Exlprer and "Private Bytes" keep going up
and up, it does go down slightly at times but not as much as it goes up.
""Jeffrey Tan[MSFT]"" <je***@online.m icrosoft.comwro te in message
news:qL******** ******@TK2MSFTN GHUB02.phx.gbl. ..

Hi Peter ,

Regarding .Net memory leak issue, an important step is determing if it is
a
managed leak or unmanaged memory leak.

Can you tell me what memory counter do you get "over 1G memory" result?
Windows has a lot of memory counters which may cause fake memory leak
conclusions. Basically, we should monitor "Process/Private Bytes"(or "VM
Size" column in task manager.) counter to determine memory leak. Note: we
should not use the "Mem Usage" column in task manager which is misleading.
I highly recommend you to download Process Explorer tool from the link
below since it is more powerful tool than task manager:
http://technet.microsoft.com/en-us/s.../bb896653.aspx

Once the "Private Bytes" is keeping increasing without decrease, it means
that the application is leaking memory. Now, you can monitor the ".Net CLR
Memory/# Bytes in all Heaps" counter. If the "Private Bytes" increases
while the ".Net CLR Memory" is stable, it indicates an unmanaged memory
leak. Otherwise, it basically means a managed memory leak. The article
below talks more information:
"I have a memory leak!!! What do i do? (defining the "where")"
http://blogs.msdn.com/tess/archive/2...leak-what-do-i
-do-defining-the-where.aspx

I will wait for your further feedback to determine if it is a managed or
unmanaged leak since they need totally different approach for
troubleshooting . Thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support

Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

=============== =============== =============== =====
Get notification to my posts through email? Please refer to
http://msdn.microsoft.com/subscripti...ult.aspx#notif
ications.

Note: The MSDN Managed Newsgroup support offering is for non-urgent issues
where an initial response from the community or a Microsoft Support
Engineer within 1 business day is acceptable. Please note that each follow
up response may take approximately 2 business days as the support
professional working with you may need further investigation to reach the
most efficient resolution. The offering is not appropriate for situations
that require urgent, real-time or phone-based interactions or complex
project analysis and dump analysis issues. Issues of this nature are best
handled working with a dedicated Microsoft Support Engineer by contacting
Microsoft Customer Support Services (CSS) at
http://msdn.microsoft.com/subscripti...t/default.aspx.
=============== =============== =============== =====
This posting is provided "AS IS" with no warranties, and confers no
rights.

[Jeffrey Tan[MSFT]]

Hi Peter,

Thanks for your feedback.

This should mean a memory leak in your application. Then, have you checked
".Net CLR Memory/# Bytes in all Heaps" counter? It will help us to
distinguish between managed/unmanaged leak in the application.

The "Mem Usage" actually means the "Working Set Size" which is the physical
RAM that a process currently uses instead of virtual memory. In modern
Virtual Memory OS, the physical RAM usage normally makes no sense to
application developer since the kernel VMM manages this. The "Working Set"
increases/decreases based on the OS paging activities and the process
working set commit. For example, if you bring a GUI application to the
foreground, it "Mem Usage" will go up immediately while many other
background applications' "Mem Usage" may decrease. This has nothing to do
with the memory leak. Also, although one applicatin is leaking memory, if
it has reached the "Working Set" charge limit, you will find that "Mem
Usage" not change anymore, but the process is still leaking. So, "Mem
Usage" is basically a useless counter.

Thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== ===========
Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

This posting is provided "AS IS" with no warranties, and confers no rights.

[Peter]

The Private Bytes counter - Keeps increasing
The # Bytes in all Heaps - Keeps increasing
Gen 0 heap size - is stable (increases and decreases)
Gen 1 heap size - is stable (increases and decreases)
Gen 2 heap size - Keeps increasing

""Jeffrey Tan[MSFT]"" <je***@online.m icrosoft.comwro te in message
news:Sx******** ******@TK2MSFTN GHUB02.phx.gbl. ..

Hi Peter,

Thanks for your feedback.

This should mean a memory leak in your application. Then, have you checked
".Net CLR Memory/# Bytes in all Heaps" counter? It will help us to
distinguish between managed/unmanaged leak in the application.

The "Mem Usage" actually means the "Working Set Size" which is the
physical
RAM that a process currently uses instead of virtual memory. In modern
Virtual Memory OS, the physical RAM usage normally makes no sense to
application developer since the kernel VMM manages this. The "Working Set"
increases/decreases based on the OS paging activities and the process
working set commit. For example, if you bring a GUI application to the
foreground, it "Mem Usage" will go up immediately while many other
background applications' "Mem Usage" may decrease. This has nothing to do
with the memory leak. Also, although one applicatin is leaking memory, if
it has reached the "Working Set" charge limit, you will find that "Mem
Usage" not change anymore, but the process is still leaking. So, "Mem
Usage" is basically a useless counter.

Thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== ===========
Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

This posting is provided "AS IS" with no warranties, and confers no
rights.

[Jeffrey Tan[MSFT]]

Hi Peter,

Thanks for your feedback.

Ok, this sounds like a managed memory leak in .Net.

To troubleshoot the managed memory leak, we normally use windbg+SOS.dll
extension which understands the internal data structure of .Net objects.
The basic idea is: first dumping all the managed objects on the managed
heap sorted by size. Then we can understand what type of object costs the
most of memory(which is the possible culprit for leaking). Then, we can use
"!gcroot" command to traverse all the root graph to find the call graph
that is holding the reference to the leaking objects. The articles talk
about the detailed steps regarding how to perform these steps:
"Tracking down managed memory leaks (how to find a GC leak)"
http://blogs.msdn.com/ricom/archive/...10/279612.aspx
".NET Memory Leak Case Study: The Event Handlers That Made The Memory
Baloon"
http://blogs.msdn.com/tess/archive/2...case-study-the
-event-handlers-that-made-the-memory-baloon.aspx

Hope it helps.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== ===========
Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

This posting is provided "AS IS" with no warranties, and confers no rights.

[Peter]

I've downloaded vadump.exe from Microsoft but I am getting error
'FAILURE query working set 24' when I run it.
and
Where can I find these tools like !dumpheap and !eeheap

I have VS2008 Archtect addition installed on my machine, but I don't have
those programs.

""Jeffrey Tan[MSFT]"" <je***@online.m icrosoft.comwro te in message
news:Tg******** ******@TK2MSFTN GHUB02.phx.gbl. ..

Hi Peter,

Thanks for your feedback.

Ok, this sounds like a managed memory leak in .Net.

To troubleshoot the managed memory leak, we normally use windbg+SOS.dll
extension which understands the internal data structure of .Net objects.
The basic idea is: first dumping all the managed objects on the managed
heap sorted by size. Then we can understand what type of object costs the
most of memory(which is the possible culprit for leaking). Then, we can
use
"!gcroot" command to traverse all the root graph to find the call graph
that is holding the reference to the leaking objects. The articles talk
about the detailed steps regarding how to perform these steps:
"Tracking down managed memory leaks (how to find a GC leak)"
http://blogs.msdn.com/ricom/archive/...10/279612.aspx
".NET Memory Leak Case Study: The Event Handlers That Made The Memory
Baloon"
http://blogs.msdn.com/tess/archive/2...case-study-the
-event-handlers-that-made-the-memory-baloon.aspx

Hope it helps.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== ===========
Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

This posting is provided "AS IS" with no warranties, and confers no
rights.

[Jeffrey Tan[MSFT]]

Hi Peter,

Thanks for your feedback.

Actually, there is no need to run vadump.exe because we have used different
counters from Process Explorer to confirm the memory leak. So we may ignore
the first 3 steps in the link below and start from the step 4:
http://blogs.msdn.com/ricom/archive/...10/279612.aspx

!dumpheap and !eeheap are both the windbg extension commands exported by
SOS.dll which is written by the CLR team for internal debugging purpose.
So, we need to install windbg to debug this memory leak instead of using VS
debugger. Yes, we can use VS debugger with SOS.dll, but it is inconvenient.
The link below talks about how to use VS debugger+SOS.dl l for .Net
debugging:
".NET Finalizer Memory Leak: Debugging with sos.dll in Visual Studio"
http://blogs.msdn.com/tess/archive/2...mory-leak-debu
gging-with-sos-dll-in-visual-studio.aspx

I prefer windbg because it is more powerful and convenient for production
debugging than VS debugger and it is free. If you have never used windbg
before, you can follow the basic setup in the blog I written below:
"How to debug application crash/hang in production environment"
http://blogs.msdn.com/msdnts/archive...pplication-cra
sh-hang-in-production-environment.asp x

After completing the windbg installation and configuration, you can follow
to start from "Step 4: Attach Windbg and load SOS" in the first blog link
above.

If there is anything unclear, please feel free to tell me, thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== ===========
Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
ms****@microsof t.com.

This posting is provided "AS IS" with no warranties, and confers no rights.