Diagnosing issues in your ASP.NET
applications in production with Visual
Studio 2012
Brad Sullivan
brads@microsoft.com

Agenda
• Challenges in Production
• Visual Studio Tools
• Remote Debugger
• IntelliTrace
• Dump Debugger
• Profiler
• Sources and Symbols

Challenges in Production
• Can’t reproduce the issue in a development environment
• Can’t run Visual Studio on the production machine
• Possibly very limited developer access to production machines
• Want to minimize impact to the server
• Performance
• Availability
• Security

Remote Debugger: The Big Hammer
• Advantages
• Often the fastest way to resolve an issue
• Xcopy deployable (%ProgramFiles%Microsoft Visual Studio
11.0Common7IDERemote Debugger)
• Configurable Authentication
• Disadvantages
• Your service becomes unresponsive if you are stopped in the debugger
• Requires some firewall configuration

Remote Debugger
TCP/IP

Improvements in Visual Studio 2012
• Single Firewall Configuration (Remote Debugger Side)
• Can connect across different domains
• Symbols load from the Visual Studio side
• No need to copy symbol files to your production machine
• Faster
• No need to choose between x86 and x64

IntelliTrace
• A “Back-in-Time” debugger
• Configurable logging to trace the state of an application over time
• Integrated with the Visual Studio Debugger UI for analysis
• Can be run either locally or via command line

IntelliTrace in Production
• Download the IntelliTrace Collector
http://www.microsoft.com/en-us/download/details.aspx?id=30665
• Run it on your production machine
• Pick a collection plan
• Target the application
• Reproduce the issue
• Bring the IntelliTrace log back to your development machine
• Analyze in Visual Studio to find the bug

IntelliTrace Collection Plans
• 2 Default Levels
• Calls
• Events
• Custom?
• Requires Editing XML
• Can turn individual events on/off
• Can include/exclude modules
• Change max log file size

Impact on Server Performance
• Depends on a number of factors
• Number of events collected
• Number of modules included in application (startup jitting costs)
• Calls data collection
• IO

System Center
• IntelliTrace is integrated with System Center 2012 SP1 – Operations
Manager
• Application Performance Monitoring now available in an IntelliTrace
format
• IntelliTrace Profiling Management Pack allows you to collect
IntelliTrace logs directly from the Operations Manager console

Dump Files
• Snapshots of the application at a single point in time
• Two major types
• With Heap – allows full inspection of the state of the app at that point in time
• Without Heap – only allows for inspection of the callstacks across all threads
• Can be opened directly in VS and debugged just like a regular
application
• Except no stepping…

Creating Dump Files in Production
• Several tools available that can create dump files, including Visual
Studio
• ProcDump has many qualities that make it ideal for production use
• Command line
• Xcopy deployable
• Provides triggers for dump collection
• CPU usage
• Memory usage
• Exceptions (with filters)
• Low impact on system performance
• Available through Microsoft SysInternals:
http://technet.microsoft.com/en-us/sysinternals/dd996900.aspx

Performance Profiler Overview
• CPU Sampling
• Shows what parts applications are executing the most frequently
• Instrumentation
• Records how long functions take to execute and how many times they are
executed
• .NET Memory Allocation
• Tracks what objects are being allocated
• Resource Contention
• Tracks when threads are contending for the same resource causing slowdowns
• Tier Interaction Profiling
• Records database queries that go through ADO.NET

Profiling Use
• Can be run locally from the IDE
• Can be run in production on the command line
• Standalone installer included in the Visual Studio Install
• “VS_INSTALL_DIRECTORYTeam ToolsPerformance ToolsSetups”
• Tier Interaction Profiling
• Find performance bottlenecks caused by how your application uses your
database
• Is used simultaneously with another profiling method (e.g. instrumentation)

Symbols (PDBs)
• The debugger, profiler, and IntelliTrace all need symbols to function
properly
• Symbols provide a mapping between the binaries you are analyzing
and the source code that produced them
• Also provide information for determining the local variables for a function
• Symbol files must exactly match the build that you are diagnosing
• It is easy for your development environment to get out of sync with
what is in production

Source Indexing
• Embeds a command into the symbol file for each source file indexed
• Diagnostic tools execute this command to fetch the source file
Exact Match

Improved User Experience
Better configuration when
retrieving indexed sources
• Trust a whole symbol file
• Trust all symbol files

Using TFS Build
• Use TFS build
definitions to save
symbols and index
sources
• Builds that are
released to production
should be saved
indefinitely

More Info About Diagnostics
ALM Team Blog: http://blogs.msdn.com/b/visualstudioalm/

Request Features
Uservoice site: http://visualstudio.uservoice.com/