I've got an issue where a thread simply hangs and never returns after calling the SQL OLE DB CCommand< Taccessor, TRowset >::Open() command using the Microsoft's Active Template Library.
Here's what the call looks like:
hr = CCommand< TAccessor, TRowset >::Open( DB::Instance()->GetSession(), CComBSTR(strCmd), pPropSet, pRowsAffected, DBGUID_DEFAULT, true, 0 );
The CCommand<>::Open() method is executing a stored procedure on a SQL Server across the network.
I managed to capture a stack trace from Process Explorer, and just looking for any clues or suggestions on a direction to help figure what's going on here.. I've included the stack trace below:
ntoskrnl.exe!KeWaitForMultipleObjects+0xc0a
ntoskrnl.exe!KeAcquireSpinLockAtDpcLevel+0x732
ntoskrnl.exe!KeWaitForMutexObject+0x19f
ntoskrnl.exe!NtWaitForSingleObject+0xde
ntoskrnl.exe!KeSynchronizeExecution+0x3a23
wow64cpu.dll!TurboDispatchJumpAddressEnd+0x6c0
wow64cpu.dll!TurboDispatchJumpAddressEnd+0x4a8
wow64.dll!Wow64SystemServiceEx+0x1ce
wow64.dll!Wow64LdrpInitialize+0x429
ntdll.dll!RtlIsDosDeviceName_U+0x24c87
ntdll.dll!LdrInitializeThunk+0xe
ntdll.dll!ZwWaitForSingleObject+0x15
ntdll.dll!RtlIntegerToUnicodeString+0x20b
MSDART.DLL!?ConvertExclusiveToShared#CReaderWriterLock3AR##QAEXXZ+0xb8
sqloledb.dll!DllUnregisterServer+0xa29b
sqloledb.dll!DllUnregisterServer+0xa05b
sqloledb.dll!DllUnregisterServer+0x9f70
sqloledb.dll+0x16e92
MyService.exe+0xea26a
This code had been working just fine for many years. This is a 32 bit C++ app, built with MS Visual Studio 2010. We started having issues after 2 changes happened and not sure if it's related or not, one the 32 bit built app is now running on a 64 bit Windows environment for the first time.. and two, the sql database is no longer local on the server, but is across the network.
This is a high volume server running hundreds or even thousands of transactions per minute, and every few days or longer, it's quite random, the code will just hang in the exact same spot, with the exact same stack trace as above..
Really would appreciate any suggestions as to how to figure out what's going on with sqloledb??
First question to start is why does the stack trace show that sqloledb is calling DllUnregisterServer?
From the stack trace it appears sql ole db is waiting for something with the WaitForMultipleObjects as the last call, but how can I figure out what it's waiting for?
Thank you.
Related
We're currently facing some issues trying to start a Service in Windows, which is an executable file and the output of a compiling process using .NET framework for C++ (Windows\Microsoft.NET\Framework\v2.0.50727).
We are able to compile, start and execute the exact same service in our DEV Environment, which consists of Windows 7 installed in Virtual Box with VisualStudio2005 (it's old software, I know...).
When we do it in our Test environment, we get a timeout error when trying to start the Service (1053: The Service Did Not Respond to the Start or Control Request in a Timely Fashion.). The server is running WindowsServer 2008 R2 Standard. We already tried to change the timeout time, without success. We also compiled the source code using the same Visual Studio 2005 SW and although we were able to compile it successfully we are still getting the same timeout message.
We are currently trying to understand what's objectively causing the different behaviour. The most obvious difference is the windows version, naturally, but since the compilation output appears identical and there are no errors during the compilation process in both environments and both output logs are identical as well we are running low on ideas to identify and validate objective differences. Our latest approach consists in trying to understand if by using Dependency Walker (dependencywalker.com) we are able to identify any issue regarding DLLs (we also checked if there is any corrupt DLL or system file in the environment and there isn't any, using the windows command for it). We're also checking some of the suggestion made on the following post: Error 1053 the service did not respond to the start or control request in a timely fashion.
Any one faced a similar issues? If so, can you suggest any kind of approach to identify the reason why the service isn't staring, other than the ones here mentioned?
Thanks in advance.
We ended up extending the timeout time regarding Service startup in Windows to 10 minutes followed by the necessary restart and we managed to start the service normally and almost immediately, which makes us think that the timeout time was never really an issue here. Although we haven't been able to pinpoint the exact cause we are still inclined to think that it was a Windows/Server related issue.
I have a .net Core web service which seems to slowly increase its cpu usage.
meaning at the first day it won't go past 10%, the second day it can go up to 20% and so on.
Using the TOP command in linux, all my webservices seems to sometime be shown there (probably when a request is made) and afterward disappear.
This specific process after running for a while just stays there constantly consuming cpu even when no request has been made.
the API still working fine, it seems like there are some threads that just keeps hanging and consuming cpu. last time I checked I had 5 threads that consumed 3-4% cpu and didn't die for some reason.
My guess is that in some specific scenario a thread just stays alive consuming cpu.
The app runs on ubuntu machine, my first step was trying to create a dump file with ProcDump so I can analyze those threads and maybe find where they are hanging.
ProcDump generates a huge 21gb file, which trying to analyze with lldb throws out of memory exception. even tried transferring it to a windows machine to debug with windbg , no help there as it couldn't open the file.
As there is no specific exception or anything I can't really share any piece of code as I have no idea where the issue is... just kind a hoping for some suggestion that might help me get to a solution or at least understand where the problem is.
Thanks a lot for reading, cheers
You could try using something like jetBrains’ DotMemory, they also have a fairly high level but helpful guide https://www.jetbrains.com/help/dotmemory/How_to_Find_a_Memory_Leak.html it also worth checking your startup file and double checking the services you’ve registered are used in the correct way ie not added as scoped when they should be transient or even a singleton etc
so iv'e been at it for a while.
Eventually found out that my problem was with HttpClient
Probably some bad mix of static class and creating new instances of HttpClient that causes the issue Iv'e explained above.
Solved it by utilizing HttpClientFactory as explained here -
https://learn.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-2.1
Lesson learned :)
A little late but Procdump for Linux just added .NET Core 3 support that generates much more managable sized core dumps. It automatically detects if the target process is .NET Core and does the right thing (i.e., no need to specify switches).
Specs: Windows 7 x64, Visual C++
Objective: I'm trying to get the remote PEB from a sample program (calc.exe e.g.). I've found the proc ID and I've opened a handle to the process with all the good rights. I've now moved on to writing a class to retrieve the location of the PEB from the process using PROCESS_BASIC_INFORMATION.
Problem: I've found several posts elsewhere that seem to indicate that the NtQueryInformationProcess turned to shit at MS. One post suggests a method of dynamic-runtime-linking NtQueryInformationProcess out of ntdll.dll. However, I think this would be unstable in the long-run (MS could remove NtQueryInformationProcess tomorrow) without extensive error handling.
This idea is realized later in this thread, and it is then suggested by Mike2343 that one should "use other methods."
Questions: What would be another method to locate the PEB of a remote process that doesn't involve NtQueryInformationProcess?
Thanks to anyone who spends any time looking at this.
Method I ended up using:
I stole pretty much all of this code and fixed it up for 64-bit. I spent a ton of time wrapping my head around various documents related to all of the different headers and structs. I also ran into an issue regarding the PE32+ format, where jcopenha was kind enough to enlighten me on a few problems I might be facing. After accounting for these problems I had a functioning program that is capable of obtaining a list of all the DLL's and their respective functions loaded in by an executable along with their relative addresses.
In retrospect, I don't think I had a good handle on what I was attempting to do. I think that I thought I was going to read in a process out of memory and find the PEB related structs or something (Later I found out that image headers and the like account for the information in the PEB). Albeit that may be possible, but what I have now is an offline example that reads in exe files and works for me.
I'm working on an application that uses multiple threads to process its data. The app is developped in C++ (Intel C++ comp. 9.1) and uses OpenMP. It is a 64 bit app running on Win7.
The problem is that when I run it during day, it runs correctly. But when I run it during night after the screen has been locked, it enters in a forever loop after a few processes.
To be more precise, the app is called many times for different files to process. The calls are done within a batch file (no problem there).
I found that it enters in the forever loop about 2 hours after the lock screen occurs.
I disabled all power saving settings. But nothing changed.
It is not very clear as description but the reason is that I don't have a clue about the source of the problem. I just hope someone among you could have had the same problem (and found a fix!). If you want more details, just let me know.
Any idea? Thanks in advance!
As my tests go on, I installed the same setup (but in release rather than debug version) on another computer. I ran into the same problem after 20 minutes (after the screen lock) with another set of data. I ran the same data on my own computer (which is not locked) and everything was fine.
I'm mystified!
Are you giving a thread priority that is taking control of the application?
Also, I would suggest taking running it through some kind of profiling, such as VTune as it can point out potential odd cases that could be causing an issue for you. (There is a free evaluation that you can try).
I am using an old version of a metastorm workflow designer.
We support this while we rewriting it in Microsoft Technologies.
After a few changes the "MAP" (*.epc) has become exceedingly slow to work with and "PUBLISH".
The publish writes the map and its binaries to the DB which then a service will pick up and execute.
However the publish "hangs" never completing and taking from a completion time of 15 min to in excess of 3 hours but still not completing.
I can see the CPU is being hammered but memory seems fine.
I ran process monitor but it does not show me much which leads me to believe the process is doing something either than the norm or the map has grown to a point which is leading it to destruction.
My question: How else can I profile this black box exe?