Advanced ASP .NET

1. Advanced ASP .NET Testing and Deployment David Grey, University of Hull

2. Introduction • Visual Studio has great support for building ASP .NET web applications • Real web application development involves more than just copying the files created in Visual Studio • In this session we look at the issue of deploying and testing ASP .NET applications

3. Demo • The sample application • Self-contained slice of large web application • Interacts with web services • Retrieves data from database • User authentication

4. Real-World Web Deployment Production Database Test Database Web Application Production Web Server Staging Web Server Developer’sWorkstation Web Application Web Application Web Application

5. Configuring Deployment • Different configurations are required for development, testing and production • Development • Local test web server, debugging, (local)test data, full source, editing support, local services • Testing • IIS, debugging?, source?, shared test data, distributed services • Production • No debugging, fully optimised, production data stores, enhanced security

6. Web Deployment Projects • Add-on for Visual Studio which offers • Pre-compilation of ASP .NET sites • Flexible options for generating compiled assemblies from a Web project • Control over assembly naming, versioning and signing • Ability to exclude, add, and transform files and directories during builds • Modification of settings in the Web.config file • Generation of MSI installer setup • Tied to configuration settings of Web project • Really useful in building real-world web applications

7. Output Options • Source files pre-compiled into assemblies • One assembly per page • Single assembly for all pages • Compiled site can be • Updateable • Page markup shipped with site • Useful for intra-organisation sites which may need modification after deployment • Non-updateable • Page markup compiled into assembly(s) • Useful for ‘boxed’ applications where end-user should not be able to modify site

8. Creating Deployment Configurations • Arbitrary sections of Web.config file can be modified for each build configuration • External file contains specific replacement for each build • WDP options specify which configuration sections should be replaced • Useful for • Changing connections strings (e.g. database) • Disabling debugging for production release

9. Demo • Creating a Web Deployment Project • Setting build options • Output format • Assembly naming, versioning and signing • Modifying configuration settings • Creating an installer

10. Deployment Wrinkles • Replacement config files show up in deployed application • Combine WDP with custom MS-Build tasks (http://waynebrantley.com/blogs/aspnetbytes/archive/2006/02/08/5.aspx#11) • Compiling sites to a single assembly and making them non-updateable can cause problems when • Minor (markup) layout errors need fixed • App must be recompiled and redeployed • Obfuscation used to protect IPR • Metadata removal/type renaming by obfuscator can cause problems in locating types when ASPX pages are removed • Using updateable pages requires code-behind types to maintain their names

11. Web Deployment Projects • Pros • No source or markup deployed to site allows for protection of intellectual property • Secure – site can be made non-updateable • Performance – precompilation avoids compilation overhead on initial page load • Cons • Must deploy all at once; can’t upgrade part of the application • Can’t compile applications with sub-virtual directories • Can interfere with continuous service as large sites are deployed (due to assembly swapping)

12. Testing • Testing is key to • Verifying web application functionality • Web unit tests • Verifying that non-functional requirements (e.g. performance, scalability) have been met • Load tests (makes use of web unit tests) • Automated testing is required • Visual Studio supports both kinds of testing against arbitrary web sites • Can be performed automatically as part of daily build cycle

13. Web Unit Testing • Black-box approach • Verifies expected page behaviour (i.e. output) when supplied with known input • Web Test Recorder • Create web test by interacting with web site in Internet Explorer • Recorder captures interactions to create test • Can capture timing information (think times) • Gives more accurate simulation of user behaviour • Can configure test parameters to be retrieved from a database

14. Demo • Recording Web tests • Executing Web tests • Using parameterised tests

15. Load Testing • Goal of load testing is to exercise application under conditions that are as close as possible to those the application will experience in real use before it goes live • Volume of users, traffic patterns and user behaviour, mix of browsers, network characteristics • Stress-testing of application by simulating multiple users accessing site • Thousands of simultaneous users • Users performing different actions • Load testing enables • worst case performance evaluations • investigation of application performance under different conditions • comparative evaluation of design alternatives to allow optimisation

16. How Load Testing Works Test Scripts TestAgent TestAgent TestAgent Application under test Test Controller

17. Defining the test mix • Users do a variety of things with a web application at the same time • Load testing can simulate this by using multiple web tests • Create web tests for each of the user activities • Select web tests to include in the load test scenario • Alter the mix (ratio) of tests to produce an activity mix similar to the real usage scenario

18. Simulating browser types • Users access your site from a range of browsers; load tests can simulate this • Out-of-box emulation support • IE 5.5, IE 6, Netscape, Pocket IE • Custom browser types can be added • Create additional browser config file in C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\Templates\LoadTest\Browsers • Obtain browser settings by opening http://www.ranks.nl/tools/envtest.html in browser you wish to emulate. Copy settings to config file

19. Simulating connection characteristics • Users access application from a variety of different networks • LAN, Broadband, Dial-up, etc • Load testing can simulate the effect of the different network bandwidths • Allows evaluation of performance experienced by client on particular types of network

20. Simulating traffic patterns • VS can simulate • Fixed user load accessing the site • Not representative of real traffic but useful for worst case analysis • Load varying over time • Ramp up from initial load to a maximum load • Think times recorded in web tests can be used to make timing of simulated web requests as close as possible to real traffic

21. Performance Counters • Monitoring of Windows performance counters is key to understanding the performance of your application • Performance counters exist for • OS (CPU/memory/IO,etc),.NET CLR, ASP .NET, IIS, SQL Server, VS testing framework • Test framework counters are monitored by default • Counters can be monitored across local and remote machines

22. Test Results • Show performance counters over time in graphical or tabular form

23. Demo • Creating a test results repository • Creating a load test • Executing the tests • Viewing live performance data • Post-test analysis

24. Web Testing with AJAX • Web Test Recorder works well with standard ASP .NET applications • Cannot properly record interactions with applications that use AJAX => test failures • Download and use Fiddler2 to record tests for AJAX applications • Add the tests created by Fiddler to the test project • Run web/load tests as normal

25. Summary • In this session we have seen how features of Visual Studio can be used to build real world web applications • Web Deployment Projects • used to control the building of web applications for testing and production • Web and load testing • used to verify the functionality and performance of Web applications

26. Links and References • Web Deployment Projects add-in http://msdn2.microsoft.com/en-us/asp.net/aa336619.aspx • Using Web Deployment Projects with Visual Studio 2005 http://msdn2.microsoft.com/en-us/library/aa479568.aspx • Web Deployment Project Enhancement http://waynebrantley.com/blogs/aspnetbytes/archive/2006/02/08/5.aspx#11 • Fiddler, http://www.fiddler2.com/fiddler2/ • The Science of Web Site Load Testing http://www.cmgitalia.it/download/seminario_marzo_2004/scienze_web_site_load_testing_savoia.pdf • Web Test Authoring and Debugging Techniques http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvs05/html/WTAuthDebug.asp • Extending Load Testing Browser Supporthttp://blog.accentient.com/PermaLink,guid,af0c2904-bc81-49f0-8156-832c09e99527.aspx