What does this IIS error log mean?

Question

I'm using Debug Diagnostic Tool, trying to understand why around 5% of the requests that are sent to my webservice just crash, without necessarily throw any error inside my application.

One of the errors this tool took is below. Can anyone here understand exactly what could be happening?

Thanks!

[6/17/2010 5:32:58 PM] First chance exception - 0xe0434f4d caused by thread with system id 1736
[6/17/2010 5:32:58 PM] Stack Trace
ChildEBP RetAddr  Args to Child              
WARNING: Stack unwind information not available. Following frames may be wrong.
1c5bec58 79ef2bbc e0434f4d 00000001 00000001 kernel32!RaiseException+0x3c
1c5becb8 79fccf80 0a6d4998 00000000 00000000 mscorwks!GetMetaDataInternalInterface+0x84a9
1c5bed7c 656cab0e 0a6d4788 1c5bed98 65221345 mscorwks!StrongNameErrorInfo+0x103dc
1c5bed88 65221345 0a6cefb0 1c5bedf8 1c5bee08 System_Data_ni+0x57ab0e
1c5bee0c 79e7e1f3 1c147158 1c147158 0a6d0710 System_Data_ni+0xd1345
1c5bee24 79f7c770 0a6d0710 1c147158 026f25a8 mscorwks!DllUnregisterServerInternal+0x21d7
1c5beee8 79e71b4c 0a6cd9b8 0a6cd994 026f409c mscorwks!CorExitProcess+0x28f9a
1c5bef00 79e821b9 1c5befd8 00000002 1c5befa0 mscorwks+0x1b4c
1c5bef80 79e96531 1c5befd8 00000002 1c5befa0 mscorwks!DllUnregisterServerInternal+0x619d
1c5bf0c8 79e96564 1c531688 1c5bf228 1c5bf120 mscorwks!CoUninitializeEE+0x2ead
1c5bf0e4 79e96582 1c531688 1c5bf228 1c5bf120 mscorwks!CoUninitializeEE+0x2ee0
1c5bf0fc 79f87a83 1c5bf120 1c5bf2e0 79fa6a6b mscorwks!CoUninitializeEE+0x2efe
1c5bf2ec 79f87be2 00629d50 0a6cdae8 0a6d0e04 mscorwks!CorExitProcess+0x342ad
1c5bf3ac 792d5348 00629d90 00000086 1c5bf3c8 mscorwks!CorExitProcess+0x3440c
1c5bf3fc 792d50f6 00629d90 00000086 066a1ae0 mscorlib_ni+0x215348
1c5bf434 792d4fde 00000000 00000000 0a6cd944 mscorlib_ni+0x2150f6
1c5bf488 65e1098e 0a6cd944 00000000 00000000 mscorlib_ni+0x214fde
1c5bf4cc 65e10665 66082f99 0a6ca144 00000000 System_Web_Services_ni+0x13098e
1c5bf4fc 65e10ff7 026c1054 0a6ca168 0a6ace9c System_Web_Services_ni+0x130665
1c5bf510 6dde7666 1c5bf54c 660adb16 6ddd2c34 System_Web_Services_ni+0x130ff7
1c5bf518 660adb16 6ddd2c34 0a6ace8c 0a6c883c System_Web_Extensions_ni+0x1c7666
1c5bf54c 6608132c 1c5bf578 0a6c883c 00000000 System_Web_ni+0x18db16
1c5bf588 6608c5c3 1c5bf5b0 0a6abecc 0a6c8b4c System_Web_ni+0x16132c
1c5bf5dc 660808ac 0a6c8218 0a6abecc 026c0d48 System_Web_ni+0x16c5c3
1c5bf5f0 66083e1c 0a6c883c 026c1054 0a6c883c System_Web_ni+0x1608ac
1c5bf62c 66083ac3 026bc67c 0a6c8400 1c5bf6b0 System_Web_ni+0x163e1c
1c5bf63c 66082c5c 8984fdc8 79e7a6b8 1c5bf858 System_Web_ni+0x163ac3
1c5bf6b0 79f9811e 00000002 01b93b00 026cf6e4 System_Web_ni+0x162c5c
1c5bf768 79f9822b 0017a0d0 1c5bf970 1c5bf9e8 mscorwks!CorExitProcess+0x44948
1c5bf7c4 79f98691 0017a0d0 1c5bf970 1c5bf9e8 mscorwks!CorExitProcess+0x44a55
1c5bf9d0 6a2aa19b 00000001 01b93b00 00000000 mscorwks!CorExitProcess+0x44ebb
1c5bf9f0 6a2aa19b 023ad3f0 01b93b00 00000002 webengine!BufferPoolReleaseBuffer+0x1bb
1c5bfa28 79e72032 79e821f6 e5934469 0017a0d0 webengine!BufferPoolReleaseBuffer+0x1bb
00000000 00000000 00000000 00000000 00000000 mscorwks+0x2032
[6/17/2010 5:33:00 PM] First chance exception - 0xe0434f4d caused by thread with system id 3252
[6/17/2010 5:33:00 PM] Stack Trace
ChildEBP RetAddr  Args to Child              
WARNING: Stack unwind information not available. Following frames may be wrong.
01d0ecd8 79ef2bbc e0434f4d 00000001 00000001 kernel32!RaiseException+0x3c
01d0ed38 79fccf80 02748edc 00000000 00000000 mscorwks!GetMetaDataInternalInterface+0x84a9
01d0edfc 656cab0e 02748ccc 01d0ee18 65221345 mscorwks!StrongNameErrorInfo+0x103dc
01d0ee08 65221345 027434d0 01d0ee78 01d0ee88 System_Data_ni+0x57ab0e
01d0ee8c 79e7e1f3 1c147158 1c147158 02744c30 System_Data_ni+0xd1345
01d0eea4 79f7c770 02744c30 1c147158 026f25a8 mscorwks!DllUnregisterServerInternal+0x21d7
01d0ef68 79e71b4c 02741ed8 02741eb4 026f409c mscorwks!CorExitProcess+0x28f9a
01d0ef80 79e821b9 01d0f058 00000002 01d0f020 mscorwks+0x1b4c
01d0f000 79e96531 01d0f058 00000002 01d0f020 mscorwks!DllUnregisterServerInternal+0x619d
01d0f148 79e96564 1c531688 01d0f2a8 01d0f1a0 mscorwks!CoUninitializeEE+0x2ead
01d0f164 79e96582 1c531688 01d0f2a8 01d0f1a0 mscorwks!CoUninitializeEE+0x2ee0
01d0f17c 79f87a83 01d0f1a0 01d0f360 79fa6a6b mscorwks!CoUninitializeEE+0x2efe
01d0f36c 79f87be2 00629d50 02742008 02745324 mscorwks!CorExitProcess+0x342ad
01d0f42c 792d5348 00629d90 00000086 01d0f448 mscorwks!CorExitProcess+0x3440c
01d0f47c 792d50f6 00629d90 00000086 066a1ae0 mscorlib_ni+0x215348
01d0f4b4 792d4fde 00000000 00000000 02741e64 mscorlib_ni+0x2150f6
01d0f508 65e1098e 02741e64 00000000 00000000 mscorlib_ni+0x214fde
01d0f54c 65e10665 66082f99 0273e664 00000000 System_Web_Services_ni+0x13098e
01d0f57c 65e10ff7 026c1054 0273e688 0a6ace9c System_Web_Services_ni+0x130665
01d0f590 6dde7666 01d0f5cc 660adb16 6ddd2c34 System_Web_Services_ni+0x130ff7
01d0f598 660adb16 6ddd2c34 0a6ace8c 0272cce4 System_Web_Extensions_ni+0x1c7666
01d0f5cc 6608132c 01d0f5f8 0272cce4 00000000 System_Web_ni+0x18db16
01d0f608 6608c5c3 01d0f630 0a6abecc 0272cff4 System_Web_ni+0x16132c
01d0f65c 660808ac 0272c6c0 0a6abecc 026c0d48 System_Web_ni+0x16c5c3
01d0f670 66083e1c 0272cce4 026c1054 0272cce4 System_Web_ni+0x1608ac
01d0f6ac 66083ac3 026bc67c 0272c8a8 01d0f730 System_Web_ni+0x163e1c
01d0f6bc 66082c5c 8984fdc8 79e7a6b8 01d0f8d8 System_Web_ni+0x163ac3
01d0f730 79f9811e 00000002 01b93b00 026cf6e4 System_Web_ni+0x162c5c
01d0f7e8 79f9822b 000dcea8 01d0f9f0 01d0fa68 mscorwks!CorExitProcess+0x44948
01d0f844 79f98691 000dcea8 01d0f9f0 01d0fa68 mscorwks!CorExitProcess+0x44a55
01d0fa50 6a2aa19b 00000001 01b93b00 00000000 mscorwks!CorExitProcess+0x44ebb
01d0fa70 6a2aa19b 023ad3f0 01b93b00 00000002 webengine!BufferPoolReleaseBuffer+0x1bb
01d0fac8 79e79cba 79e79ccd 0000000d 00000000 webengine!BufferPoolReleaseBuffer+0x1bb
01d0facc 79e79ccd 0000000d 00000000 79ec3f4b mscorwks+0x9cba
01d0fad8 79ec3f4b 79e7c82c 79ec3f53 f818458d mscorwks+0x9ccd
00000000 00000000 00000000 00000000 00000000 mscorwks!CreateAssemblyNameObject+0x22f40
[6/17/2010 5:33:37 PM] Thread exited. Exiting thread system id - 2144. Exit code - 0x00000000

EDIT: This is what I get from the client side:

http://stackoverflow.com/questions/3302587/invalidoperationexception-when-getting-into-the-alternative-flows-of-a-ws-call

EDIT 2: The error had been resolved by its own :S Great, because I had no clue on how resolving this..

Answer 1

What you have posted is the unmanaged stack. You need to use something like sos.dll to convert this stack to the managed code. 1) Open the .dmp in WinDbg.

2) Load sos.dll

3) Run CLRStack and DumpStack on the thread that had the exception.

This will produce the managed stack and should tell you what file and line is having the issue.

DebugDiags/WinDbg/SOS is the best way that I have found to track down these types of issues so this is a great debugging technique to get good at. As mentioned earlier, Tess' blog has a lot of information related to using SOS in various situations. There is also a lot of information on the SOS.dll page.

Answer 2

OK, This is purely just a guess but I bet something like this is going on, it looks like some process is exiting from this function ...

CorExitProcess

Since this is IIS, maybe an Application Pool is recycling or shutting down.

Next it seems to be calling DllUnregisterServer which is called by CoUnitializeEx, so this sounds like somewhere you have a COM object, my gut tell me the COM object is implemented in .net from the call to StrongNameErrorInfo since strong names of more like a .net era thing than a COM era term.

Again this is all speculation, Do you have any objects that fit this bill, alternatively, do you have any .net dlls that you are using that haven't been Gac'd correctly? Or maybe were added to the gac and are no longer present on the machine or the strong name key was changed for some reason?

Hope this helps and doesn't hinder :)

What seems strange to me about this is that you are getting strong name issues on unitialize rather than initialize, hmm, intruiging