Beyond Breakpoints David Truxall, Ph.D. Debugging and Troubleshooting Principal Consultant

Production application with a problem

Finding bugs is difficult and costly

Tools and Techniques Find and Prevent Bugs

Prevent bugs with good process

Recognize the source of bugs

What is a bug? Crashes Freezes/Hangs Poor Performance Incorrect Results Security Holes Inconsistent UI

How do you debug? Reproduce the bug Document the bug Investigate Use tools Fix it Test the fix Document the fix

Reproduce the bug

Document the bug

Investigate

Use tools

Fix it

Test the fix

Document the fix

Know the tools

Testing

Unit tests Under your control!

Under your control!

Regression tests Check fixes today Keep bugs away tomorrow

Check fixes today

Keep bugs away tomorrow

Continuous Integration

Tools make the process work Profilers Load Testing Platform-specific tools

Profilers

Load Testing

Platform-specific tools

Profiling

Load Testing Scalability Leaks Interaction

Scalability

Leaks

Interaction

Platform-specific tools Web Fiddler LogParser WebLog Expert YSlow Firebug IEDeveloper Toolbar See Scott Hanselmans’s tools list

Web

Fiddler

LogParser

WebLog Expert

YSlow

Firebug

IEDeveloper Toolbar

Prevent bugs while coding Learn the tools Write good code Check your work

Learn the tools

Write good code

Check your work

Learn the features

Breakpoints

Watches

Code Practices Assertions Tracing and Logging Symbols

Assertions

Tracing and Logging

Symbols

Assertions Debug.Assert(predicate) Trace.Assert(predicate)

Tracing and Logging Finding errors when you can’t debug

Finding errors when you can’t debug

Symbols

Code Examination

FxCop

Poor performance == Obvious File System Access Encryption

Use WinDBG to find the hard bugs

Set up and configure

SOS.dll

Symbols

ADPlus

Demo: WinDBG Application Hang Memory Leak

Application Hang

Memory Leak

Find the Bugs!

Thank You! [email_address] http://dotnetjunkies.com/WebLog/davetrux/ This presentation: http://www.slideshare.net/davetrux/slideshows

[email_address]

http://dotnetjunkies.com/WebLog/davetrux/

This presentation: http://www.slideshare.net/davetrux/slideshows