PerfView tool for memory analysis

Steps to perform memory analysis:

PerfView is very usefull tool to from Microsoft to analyze, memory and performance issues. In this section we will see how to use PerfView tool to perform memory leak analysis.

1. Collect the full memory dump file for the exe to be investigated.
Use Task manager->Select the process -> Right click Create Dump File. to save the dump. Else use ProcDump.exe with "-ma" option (Available in SysInternals website) to create full memory dump.

2. Open the dump file using PerfView.exe

3. "Dump GC Heap" button shall walk through the heap and start dumping them into .GCHeap File. 

4. If we are debugging Live process then ForceGC, Freeze would options make sense. Anyway now we are checking already collected dump file.

5. Double click on "GCHeap" dump file to view the stack table.

6. Stack table contains various Filter options.

7. Options like Inc, IncCount shall help you to find which object occupies the heap. most of the Array or String used to be on Top of all the  memory allocated. 

8. We could use options like Fold, Drill Into, F10 to see who is really referring this objects.

9. As soon as we know the major reference holding live objects, we should be able to find the root cause.

10. Apart from great table view, PerfView also provide Diff option if we collected the heap snap shots on difference time interval of the same process to find the leaking objects and the root holding the objects.

Debugging using WinDBG, Root cause finding using WER.

Finding the root cause from WER:

From wer file info, I got 34a5.

6.1                                 7601 Service Pack 1                                 (0x7): Windows Server 2008 R2 Standard                                 ServerStandard                                 7601.17944.amd64fre.win7sp1_gdr.120830-0333                                 1130                                 Multiprocessor Free                                 X64                                 1033

               

                                640

                                C:\Windows\System32\services.exe

                                C:\Windows\system32\services.exe

               

               

                                CLR20r3

                                loggersvc.exe

                                1.0.4668.23049

                                5077f573

                                mscorlib

                                2.0.0.0

                                4ef6c131

                                34a5

                                b2

                                System.IO.IOException

               

               

                                6.1.7601.2.1.0.272.7

                                1033

               

               

                                62F68A02-4CCC-4EFA-B6D6-446950477748

                                Dell Inc.

                                PowerEdge T610

                                2.2.10

               

1.       !token2ee mscorlib_ni 060034a5 – bcoz “06xxxxxx” is standard. – mscorlib is the guy who failed.

O/P: !token2ee mscorlib 060034a5 0:012> !token2ee mscorlib_ni 060034a5 Module: 000007fef8e91000 (mscorlib.dll) Token: 0x00000000060034a5 MethodDesc: 000007fef8f0fd00 Name: System.IO.__Error.WinIOError(Int32, System.String) JITTED Code Address: 000007fef9163fa0

2.       !dumpil 000007fef8f0fd00 – Go to method and also go to b2 since this is the offset

O/P: ilAddr = 000007fef96dba58 IL_0000: ldarg.0 IL_0001: ldc.i4.s 123 IL_0003: beq.s IL_000f IL_0005: ldarg.0 IL_0006: ldc.i4 161 IL_000b: ceq IL_000d: br.s IL_0010 IL_000f: ldc.i4.1 IL_0010: stloc.0 IL_0011: ldarg.1 IL_0012: ldloc.0 IL_0013: call System.IO.__Error::GetDisplayablePath IL_0018: stloc.1 IL_0019: ldarg.0 IL_001a: stloc.2 IL_001b: ldloc.2 IL_001c: ldc.i4.s 80 IL_001e: bgt.s IL_005f IL_0020: ldloc.2 IL_0021: ldc.i4.s 15 IL_0023: bgt.s IL_004a IL_0025: ldloc.2 IL_0026: ldc.i4.2 IL_0027: sub IL_0028: switch (IL_009a, IL_00d9, IL_025b, IL_011a) IL_003d: ldloc.2 IL_003e: ldc.i4.s 15 IL_0040: beq IL_019c IL_0045: br IL_025b IL_004a: ldloc.2 IL_004b: ldc.i4.s 32 IL_004d: beq IL_01d8 IL_0052: ldloc.2 IL_0053: ldc.i4.s 80 IL_0055: beq IL_021d IL_005a: br IL_025b IL_005f: ldloc.2 IL_0060: ldc.i4 183 IL_0065: bgt.s IL_007f IL_0067: ldloc.2 IL_0068: ldc.i4.s 87 IL_006a: beq IL_01c5 IL_006f: ldloc.2 IL_0070: ldc.i4 183 IL_0075: beq IL_015b IL_007a: br IL_025b IL_007f: ldloc.2 IL_0080: ldc.i4 206 IL_0085: beq IL_018c IL_008a: ldloc.2 IL_008b: ldc.i4 995 IL_0090: beq IL_0255 IL_0095: br IL_025b IL_009a: ldloc.1 IL_009b: callvirt System.String::get_Length IL_00a0: brtrue.s IL_00b2 IL_00a2: ldstr "IO.FileNotFound" IL_00a7: call System.Environment::GetResourceString IL_00ac: newobj System.IO.FileNotFoundException::.ctor IL_00b1: throw IL_00b2: call System.Globalization.CultureInfo::get_CurrentCulture IL_00b7: ldstr "IO.FileNotFound_FileName" IL_00bc: call System.Environment::GetResourceString IL_00c1: ldc.i4.1 IL_00c2: newarr System.Object IL_00c7: stloc.3 IL_00c8: ldloc.3 IL_00c9: ldc.i4.0 IL_00ca: ldloc.1 IL_00cb: stelem.ref IL_00cc: ldloc.3 IL_00cd: call System.String::Format IL_00d2: ldloc.1 IL_00d3: newobj System.IO.FileNotFoundException::.ctor IL_00d8: throw IL_00d9: ldloc.1 IL_00da: callvirt System.String::get_Length IL_00df: brtrue.s IL_00f1 IL_00e1: ldstr "IO.PathNotFound_NoPathName" IL_00e6: call System.Environment::GetResourceString IL_00eb: newobj System.IO.DirectoryNotFoundException::.ctor IL_00f0: throw IL_00f1: call System.Globalization.CultureInfo::get_CurrentCulture IL_00f6: ldstr "IO.PathNotFound_Path" IL_00fb: call System.Environment::GetResourceString IL_0100: ldc.i4.1 IL_0101: newarr System.Object IL_0106: stloc.s VAR OR ARG 4 IL_0108: ldloc.s VAR OR ARG 4 IL_010a: ldc.i4.0 IL_010b: ldloc.1 IL_010c: stelem.ref IL_010d: ldloc.s VAR OR ARG 4 IL_010f: call System.String::Format IL_0114: newobj System.IO.DirectoryNotFoundException::.ctor IL_0119: throw IL_011a: ldloc.1 IL_011b: callvirt System.String::get_Length IL_0120: brtrue.s IL_0132 IL_0122: ldstr "UnauthorizedAccess_IODenied_NoPathName" IL_0127: call System.Environment::GetResourceString IL_012c: newobj System.UnauthorizedAccessException::.ctor IL_0131: throw IL_0132: call System.Globalization.CultureInfo::get_CurrentCulture IL_0137: ldstr "UnauthorizedAccess_IODenied_Path" IL_013c: call System.Environment::GetResourceString IL_0141: ldc.i4.1 IL_0142: newarr System.Object IL_0147: stloc.s VAR OR ARG 5 IL_0149: ldloc.s VAR OR ARG 5 IL_014b: ldc.i4.0 IL_014c: ldloc.1 IL_014d: stelem.ref IL_014e: ldloc.s VAR OR ARG 5 IL_0150: call System.String::Format IL_0155: newobj System.UnauthorizedAccessException::.ctor IL_015a: throw IL_015b: ldloc.1 IL_015c: callvirt System.String::get_Length IL_0161: brfalse IL_025b IL_0166: ldstr "IO.IO_AlreadyExists_Name" IL_016b: ldc.i4.1 IL_016c: newarr System.Object IL_0171: stloc.s VAR OR ARG 6 IL_0173: ldloc.s VAR OR ARG 6 IL_0175: ldc.i4.0 IL_0176: ldloc.1 IL_0177: stelem.ref IL_0178: ldloc.s VAR OR ARG 6 IL_017a: call System.Environment::GetResourceString IL_017f: ldarg.0 IL_0180: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_0185: ldarg.1 IL_0186: newobj System.IO.IOException::.ctor IL_018b: throw IL_018c: ldstr "IO.PathTooLong" IL_0191: call System.Environment::GetResourceString IL_0196: newobj System.IO.PathTooLongException::.ctor IL_019b: throw IL_019c: call System.Globalization.CultureInfo::get_CurrentCulture IL_01a1: ldstr "IO.DriveNotFound_Drive" IL_01a6: call System.Environment::GetResourceString IL_01ab: ldc.i4.1 IL_01ac: newarr System.Object IL_01b1: stloc.s VAR OR ARG 7 IL_01b3: ldloc.s VAR OR ARG 7 IL_01b5: ldc.i4.0 IL_01b6: ldloc.1 IL_01b7: stelem.ref IL_01b8: ldloc.s VAR OR ARG 7 IL_01ba: call System.String::Format IL_01bf: newobj System.IO.DriveNotFoundException::.ctor IL_01c4: throw IL_01c5: ldarg.0 IL_01c6: call Microsoft.Win32.Win32Native::GetMessage IL_01cb: ldarg.0 IL_01cc: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_01d1: ldarg.1 IL_01d2: newobj System.IO.IOException::.ctor IL_01d7: throw IL_01d8: ldloc.1 IL_01d9: callvirt System.String::get_Length IL_01de: brtrue.s IL_01f7 IL_01e0: ldstr "IO.IO_SharingViolation_NoFileName" IL_01e5: call System.Environment::GetResourceString IL_01ea: ldarg.0 IL_01eb: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_01f0: ldarg.1 IL_01f1: newobj System.IO.IOException::.ctor IL_01f6: throw IL_01f7: ldstr "IO.IO_SharingViolation_File" IL_01fc: ldc.i4.1 IL_01fd: newarr System.Object IL_0202: stloc.s VAR OR ARG 8 IL_0204: ldloc.s VAR OR ARG 8 IL_0206: ldc.i4.0 IL_0207: ldloc.1 IL_0208: stelem.ref IL_0209: ldloc.s VAR OR ARG 8 IL_020b: call System.Environment::GetResourceString IL_0210: ldarg.0 IL_0211: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_0216: ldarg.1 IL_0217: newobj System.IO.IOException::.ctor IL_021c: throw IL_021d: ldloc.1 IL_021e: callvirt System.String::get_Length IL_0223: brfalse.s IL_025b IL_0225: call System.Globalization.CultureInfo::get_CurrentCulture IL_022a: ldstr "IO.IO_FileExists_Name" IL_022f: call System.Environment::GetResourceString IL_0234: ldc.i4.1 IL_0235: newarr System.Object IL_023a: stloc.s VAR OR ARG 9 IL_023c: ldloc.s VAR OR ARG 9 IL_023e: ldc.i4.0 IL_023f: ldloc.1 IL_0240: stelem.ref IL_0241: ldloc.s VAR OR ARG 9 IL_0243: call System.String::Format IL_0248: ldarg.0 IL_0249: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_024e: ldarg.1 IL_024f: newobj System.IO.IOException::.ctor IL_0254: throw IL_0255: newobj System.OperationCanceledException::.ctor IL_025a: throw IL_025b: ldarg.0 IL_025c: call Microsoft.Win32.Win32Native::GetMessage IL_0261: ldarg.0 IL_0262: call Microsoft.Win32.Win32Native::MakeHRFromErrorCode IL_0267: ldarg.1 IL_0268: newobj System.IO.IOException::.ctor IL_026d: throw

I used the below links to find this out.

1.       http://stackoverflow.com/questions/3218649/how-to-analyse-werinternalmetadata-xml-file-generated-by-windows-crash-reporter           (*)

2.       http://blogs.msdn.com/b/oanapl/archive/2009/01/30/windows-error-reporting-wer-and-clr-integration.aspx - actual link which helped me

3.       http://blogs.msdn.com/b/oanapl/archive/2009/01/28/windows-error-reporting-wer-for-developers.aspx

4.       http://www.codeilove.com/2012/09/debugging-using-windows-error-reporting.html

5.       http://stackoverflow.com/questions/522522/how-can-i-view-the-local-variables-on-the-evaluation-stack-when-debugging-a-net

Debugging .Net applications crash using WinDbg

Commands:

1. .loadby sos clr

This command needed to load the SOS.dll and show you the CLR types and .net call stacks during debugging.

2. !threads

Displays all the threads information.

3. ~ s

Sets the particular thread.

4. !clrstack

Displays the .net callstack.

5.!dumpstack

Displays both native and .net call stack together.

6. ~* e !clrstack

Displays all threads call stack.

7. !pe

prints the exception if any present in the current threads

!pe -nested shall display nested exceptions if present.

8. !dumpheap -stat

Displays the heap status.

9. !dso 

Dumps the stack objects for current threads.

10. !dumpheap -type [Data Type you want to investigate]

Dumps the specified data type from the heap.

Setup for Programming cloud using Google App Engine

How to setup the machine for Cloud programming using Google app engine.

In this section we will see how to setup the machine programming Google app engine for windows using Python 2.7.

1. You need down load and install Python 2.7 version.
Google app engine works with Python2.7 version not Python2.5 version.
You can down the Python from Python.org. Direct download for Win7/8 from python-2.7.6.amd64.msi

2. You need log-in to google devwlopers site and  https://developers.google.com/appengine/downloads.
Down load the MSI and install.

Now you are ready to create the application locally in your machine.