I am getting a System.OutOfMemoryException from my vb.net application, it happened from one certain user. I am trying to figure out whether my application takes too much memory space or the PC has low memory. But she just upgraded her desktop as i3 Intel CPU and higher memory.
Is there any tool that I check memory consumption when code is executed as go through lines?
By the way, it is developed by vs2010 and It is a Windows application.
<--Edit-->
I found the problem from my application. I did not mention because I did not know what the problem was. I am using a Google map inside of vb.net application. It takes a memory whenever I search a map on web browser which is on a form . Even though I close the form, it is not disappeared from
memory. It is just going up. That goes away when I close MDI form. FYI..
The best tool we've worked so far is the JetBrains profiler (http://www.jetbrains.com/profiler/features/).
That's a common error. It normally happens when the application enters a loop that never ends... (infinite loop).
Is it a Console, WinForms, ASP, WPF?
Try to identify during which Event your application throws the exception and put a try catch to print out more details.
Just check out this cool WPF performance suite to check out if you have memory leaks:
Performance Toolkit
Or check out if you can use GC.Collect() to find the leak.
Also you can accecss in Process Explorer to any .Net memory data and peaks.
Regards
Related
I have an vb.net application I distribute to my analysts – We assign perhaps 100 200MB images at a time. The app sequentially opens the large jpg image using GDI+ and the image is placed in the LOH. I scan each pixel looking for data. - when done I dispose the image and use GC.collect. But this does not clear the LOH, and as a result the LOH keeps increasing until the app crashes. A work around is to chop the assignment into 25 instance chunks, but this is risky as our analysts often do this late at night – perhaps after a beer or 2.
The C# construct is
GCSettings.LargeObjectHeapCompactionMode = GCLargeObjectHeapCompactionMode.CompactOnce
but there is no GCSettings available in vb.net
My vb.net code is
loadedImage.Dispose()
MasterImage.Dispose()
GC.Collect()
Finalize()
But I cannot find a vb.net method to force the LOH compaction
When done
Can you help?
GCSettings.LargeObjectHeapCompactionMode was added in .NET 4.5.1. It exists in VB.NET as well as C#. You're probably targeting a lower version of the .NET runtime. If you want access to this feature you will need to compile against a framework version of 4.5.1 or higher.
This likely won't solve the underlying problem, however. Your leak may not even be where you think it is. Profiling your application with an allocation profiler is the best way to track down resource leaks. Without a Minimal, Complete, and Verifiable example, it is difficult to guess where your application may be going wrong.
I work on a Classic ASP web application that uses several old COM components written in VB6. All of the VB6 components are registered in a COM+ application that run in their own dllhost process. A large majority of the application has been converted to .Net, but there are still a lot of legacy pages and components. COM Interop is used in both directions, calling some .Net assemblies from classic ASP and VB6 as well as calling VB6 components from ASP.Net. The application is running on Windows Server 2008 R2 (IIS 7.5) in the classic pipeline mode.
For the most part the application works fine. The transition to .Net effort was ultimately abandoned, with a new product being developed instead. In the meantime, the old product must be maintained in it's heterogeneous state.
I am having trouble tracking down an intermittent problem where the web application hangs. Users just see a blank screen while their browser waits and the server never responds. The hang persists until I manually kill the dllhost process that's hosting the VB6 components, so I believe the problem is buried there. Probably a memory leak or runaway circular loop.
There are thousands of users on the system daily, but the problem only happens once or twice a week. Fortunately we have a web farm that automatically pulls a server out when it stops responding, so the customer impact is zero. Still, I would like to figure out what's going on.
I have recompiled all of the VB6 components to include debugging symbols and redeployed to production. When the problem happens, I use the 32-bit task manager (c:\windows\syswow64\taskmgr.exe) to take a crash dump of the dllhost process. I end up with a dllhost.dmp file, which I bring down to my development workstation and open in VS2010. I have the .pdb symbol files that VB6 created in my symbols path. When I start the debugging session in VS2010, I can go to the Modules screen and see that indeed all of the symbols for my components are loaded.
Where to go from here? The call stack doesn't show any of my own components. It looks like this:
The disassembly at the top of the call stack looks like this:
Not sure what else I can do. I examined all of the locals at every frame of the call stack and it's gibberish to me. I don't see any references to any of my own components.
Perhaps WinDbg would yield more information? Not sure where to start with it.
I'm pretty sure that if I could just find what VB6 class/method was being called when the hang occurred that I could get to the bottom of it. I've tried adding some logging, and the results are inconsistent.
Perhaps there's nothing wrong with my VB6 components at all, but I'm hitting on some bug within Windows or IIS?
Any advice would be appreciated, but throwing away VB6 is not an option at this point. Thanks.
Not a complete answer, but CoRegisterSurrogateEx is documented to block as long as the surrogate process is running:
The CoRegisterSurrogateEx function is a blocking function. It does not
return until COM+ has determined that the process will be shut down.
Before calling this function, initialize COM on this thread as a
multi-threaded apartment (MTA).
So I don't think the error is on this call-stack. (You can see it was still blocking on a WaitForSingleObject call, most likely the mechanism it uses to block until the process is to be shut down).
I have an XNA application that communicates with another process (on the same computer) using WCF.
On each Update cycle, the XNA will get data from the other process.
The XNA runs fine when in a window (over 60fps),
but if I try to run it fullscreen, I'm getting less than 1fps.
This does not happen if I turn off the WCF.
Why would fullscreen affect it like that ?
Any ideas ?
Thanks.
This seems like a long shot, providing that there's not much details, but it looks to me you have some thread starvation issues, possibly caused by page flip / buffer swap waiting for something? (What OS are you using, how many cores)
You should try using the profiler and analyzing the code to see where is the critical secion.
For a quick fix, try using Thread.Sleep(1), or switching to Async calls for your WCF service.
I am getting Out of Memory errors in classic ASP, probably where attempting to access data. For example:
Microsoft VBScript compilation error '800a03e9'
Out of memory
(some file) Line 0
These errors only happen once in a while and they keep happening for a few minutes and then the webserver must be restarting the app pool because all sessions are lost.
What is a good tool for finding/diagnosing memory leaks in a classic ASP application that makes heavy use of ADO for data access and a couple of other off the shelf COM objects.
Presumably any memory leaks would be from the COM object rather than the script, so a general Windows debugger or leak finder might be what I need. Any advice on what would be appropriate?
Or any other thoughts on what might cause these errors?
Unfortunately, tracking down memory leaks is not an easy task :-(
Here's a good summary of things to watch out for here:
http://www.leinadium.com/code/classic-asp-memory-leaks-in-iis/
Be sure to read the link inside that post as well for a list of tools.
Good luck!
Microsoft has a good utility umdh.exe that may be good for finding leaks in this situation. It allows you to take a "snapshot" at one point, exercise the application (e.g., IIS) then take another snapshot and compare the memory usage differences.
if
you try to get one row data with EOF OR BOF
or
the database connection is close or readony you try to wirte!
you should get the ERROR.
I've used the CF Remote Performance Monitor, however this seems to only track memory initialised in the managed world as opposed to the unmanaged world. Well, I can only presume this as the numbers listed in the profiler are way short of the maximum allowed (32mb on CE 5). Profiling a particular app with the RPM showed me that the total usage of all the caches only manages to get to about 12mb and then slowly shrinks as (I assume) something unmanaged starts to claim more memory.
The memory slider in System also shows that the device is very short on memory. If I kill the process the slider shows all the memory coming back. So it must (?) be this managed process that is swallowing the memory.
Is there any simple(ish?) fashion how one can track unmanaged memory usage in some way that might enable me to match it up with the corresponding P/Invoke calls?
EDIT: To all you re-taggers it isn't .NET, tagging the question like this confuses things. It's .NETCF / Compact Framework. I know they appear to be similar but they're different because .NET rocks whereas CF is basically just a wrapper around NotImplementedException.
Try enabling Interop logging.
Also, if you have access to the code of the native dll you are using, check this out: http://msdn.microsoft.com/en-us/netframework/bb630228.aspx
I've definitely been fighting with unmanaged issues in a C# managed app for a while -- it's not easy.
What I've found to be most helpful is to have a regular output to a text log file. For example you can print the output of GlobalMemoryStatus every couple of minutes along with logging every time you load a new form. From there you can at least see that either memory gradually erodes, or a huge chunks of memory disappeared at specific times of the day.
For us, we found a gradual memory loss all day as long as the device was being used. From there we eventually found that the barcode scanning device was being initialized for no particular reason in our Form base class (I blame the previous developer! :-)
Setting up this logging may be a small hassle, but for us it paid huge dividends in the long run especially with the device in live use we can get real data, instrumentation, stack traces from exceptions, etc.
Ok, I'm using C++ on CE, not C# so this may not be helpful, but...
I use a package called Entrk toolbox which monitors memory and resource usage, leaks, and exceptions under Windows CE. Pretty much like a lightweight CE version of boundschecker. Does the trick most times.