DebuggingDemos

Demos for .NET Debugging Presentations

If you came here looking for debugging info or labs, check out my blog https://www.tessferrandez.com

Preparations

1. Install DebugDiag
2. Install ProcDump
3. Install WinDbg
4. Download and compile Netling easy load tester
5. In WinDbg, Set the sympath to srv*c:\symcache*https://msdl.microsoft.com/download/symbols and save workspace

Use magnifier with bar to manify command in windbg

Capture demo dumps

1. Crash - Presidents demo - next on Obama
2. Crash - MyShop - Contact - Email=Test --- need to capture with a debug diag rule, dump on first chance stack overflow
3. Hang - MyShop - Products - Netling 8/10/1 (can take with taskmanager if you set up vdir in real IIS 64 bit)
4. Memory - MyShop - News - Netling 4/10/1 (take one baseline before and one leak after)

Script

Dump walkthrough

1. Open crash 1 in WinDbg

2. Add commands to scratchpad

3. Walk through commands and explain what we can find in a memory dump

      ~* kb
      .loadby sos clr
      !clrstack
      !dso
      !do <exception>
      !objsize <exception>
      !click <message>
      !gcroot <message>
      lm
      !eeheap -gc
      !dumpheap -stat
   

Crash 1

1. Repro crash in presidents - next on Obama
2. Procdump -ma ThePresidents.exe -e
3. in Windbg !clrstack and !dso
4. Open in Debug Diag

• exception on stack 0
• stack of T0
• previous exceptions
• discuss SOF/OOM/EE

5. Open in Visual Studio (managed)
6. Open event viewer

(*) debug diag rules

Hang 1

1. Browse to Products (MyShop)
2. Netling 8/10/1 + task manager (check CPU)
3. Netling again - dump with task manager (*) Windbg - show lots of same stacks
4. Debug Diag

• show wait
• http context report

5. Visual studio (Mixed??)

• Parallel stacks

Hang 2

1. Open presidents, show slowness on next
2. Analyze/Performance Profiler

• Performance wizard
• Instrumentation

3. Repro / Stop profiling
4. Summary - App.Run - move down path

Memory 1

1. Browse news
2. dump for comparison
3. Netling 4/10/1
4. Dump leak
5. Open in VS

• sort by size diff bytes
• newscontroller root down

6. Open in Debug Diag

• see cache

(*) open in Windbg and debug with !gcroot etc.

Slides available on my Slideshare