Classic asp (vb6) application crashes with 100% CPU usage

I'm having trouble with an old legacy app that recently started crashing. I'm trying to investigate the DebugDiag analysis, but don't have much luck. Either there is a sql query that locks and somehow the calling thread doesn't die away? Then again callstack points to oledb32!CImpIErrorInfo::GetHelpFile+a1.

Here's the info from DebugDiag which I think is relevant to this problem:

The following threads in w3wp.exe_MyApp_PID_7572_Date__10_21_2010__Time_08_43_22AM_720_Manual Dump.dmp are making a database operation using ADO.

The call to MSADO15!CERRORLOOKUP::GETHELPINFO originated from oledb32!CImpIErrorInfo::GetHelpFile+a1

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Thread 17 - System ID 4160 Entry point msvcrt!_endthreadex+2f Create time 21.10.2010 0:08:16 Time spent in user mode 0 Days 00:11:22.781 Time spent in kernel mode 0 Days 00:27:49.953

This thread is making a database operation using ADO.

The call to MSADO15!CERRORLOOKUP::GETHELPINFO originated from oledb32!CImpIErrorInfo::GetHelpFile+a1

Function Source ntdll!GetUILangID+31

ntdll!LdrpSearchResourceSection_U+186

ntdll!LdrFindResource_U+18

kernel32!FindResourceExW+65

user32!LoadStringOrError+31

user32!LoadStringW+18

msado15!FetchInfo+ba

msado15!CErrorLookup::GetHelpInfo+1e

oledb32!CImpIErrorInfo::GetHelpFile+a1

msvbvm60!ExecProj::SetModuleCount+a

msvbvm60!CEcProjTypeComp::Release+4

msvbvm60!RcmConstructModuleInstance+8f

oleaut32!DispCallFunc+16a

msvbvm60!VBStrToLong+cf

msvbvm60!FileOutString+bb

msvbvm60!_vbaPrintObj+51

MSWCRUN!DllUnregisterDesigner+8ad3

MSWCRUN!DllUnregisterDesigner+accb

MSWCRUN!DllUnregisterDesigner+af8c

MSWCRUN!DllUnregisterDesigner+a7de

MSWCRUN!DllUnregisterDesigner+7b51

MyApp!DllCanUnloadNow+212e

oleaut32!DispCallFunc+16a

msvbvm60!VBStrToLong+cf

msvbvm60!FileOutString+bb

msvbvm60!_vbaPrintObj+51

MSWCRUN!DllUnregisterDesigner+8ad3

MSWCRUN!DllUnregisterDesigner+7d13

MSWCRUN!DllUnregisterDesigner+6e64

MSWCRUN!DllUnregisterDesigner+9097

MSWCRUN!DllUnregisterDesigner+8fa6

vbscript!IDispatchInvoke2+b2

vbscript!IDispatchInvoke+59

vbscript!InvokeDispatch+13a

vbscript!InvokeByName+42

vbscript!CScriptRuntime::RunNoEH+234c

vbscript!CScriptRuntime::Run+62

vbscript!CScriptEntryPoint::Call+51

vbscript!CSession::Execute+c8

vbscript!COleScript::ExecutePendingScripts+144

vbscript!COleScript::SetScriptState+14d

asp!CActiveScriptEngine::TryCall+19

asp!CActiveScriptEngine::Call+31

asp!CallScriptFunctionOfEngine+5b

asp!ExecuteRequest+17e

asp!Execute+24c

asp!CHitObj::ViperAsyncCallback+3f0

asp!CViperAsyncRequest::OnCall+92

comsvcs!CSTAActivityWork::STAActivityWorkHelper+32

ole32!EnterForCallback+c4

ole32!SwitchForCallback+1a3

ole32!PerformCallback+54

ole32!CObjectContext::InternalContextCallback+159

ole32!CObjectContext::DoCallback+1c

comsvcs!CSTAActivityWork::DoWork+12d

comsvcs!CSTAThread::DoWork+18

comsvcs!CSTAThread::ProcessQueueWork+37

comsvcs!CSTAThread::WorkerLoop+190

msvcrt!_endthread开发者_JAVA技巧ex+a3

kernel32!BaseThreadStart+34

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Client connection from 194.241.111.228:26238 to 81.175.250.2:80

Host Header 81.175.250.2:80 GET request for /MyApp/netk.asp HTTP Version HTTP/1.1 SSL Request False Time alive 00:49:33 QueryString

Request mapped to

HTTP Request State HTR_READING_CLIENT_REQUEST Native Request State NREQ_STATE_PROCESS

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Hard to say, but I'd start with throwing ProcessMonitor/RegMon/FileMon/TcpViewer from live.sysinternals.com. Fiddler wouldn't be a bad idea either.

Then, if you still get no clues, I'd break out WinDBG, which is always my nuclear option, because the learning curve is so massive. But, assuming, you learn the commands, you could break on the crash, then walk the stack backwards and potentially figure out where the error is coming from.

And of course, you could just reinstall everything and that will probably solve all your problems.