Quick Resource Box

• dynaTrace AJAX Edition
• patterns & practices: Performance Testing Guidance
• Performance Testing Guidance How-To's

In the post Andreas provides a list of reasons for “Why do Load Testing Projects fail?” and that is:

• Application is not ready for testing.
• No real life test use cases and test data.
• Problems with the Load Testing Infrastructure.
• Not enough data was captured during the load test.

I thought it’d be useful to compile quick checklist to help reduce the risk of being unprepared toward load testing effort. The checklist can be used by a PM [project manager] when estimating the efforts.

Application Readiness

• Key test scenarios identified. Key scenarios are:
• High usage rate. For example, search.
• Highly technical. For example, heterogeneous tech, complex algorithms.
• High visibility. For example, yearly revenue report for CEO.
• Key scenarios functional bugs free. You do not want to measure response time of HTTP 404 or HTTP 500.
• Application responds well for several users. Call it smoke test.
• Application functionally tested in the environment where perf testing is going to be performed.

Real Life Test Use Cases and Test data

• Test users created in your identity management store.
• Success criteria/objectives identified.

Load Testing Infrastructure Readiness

• There is enough licenses to perform load testing.
• Test automation technically capable to simulate use cases.
• Test hardware is not a perf bottleneck.

Captured Data is Representative

• Test metrics identified.

Related Books

• Ultra-Fast ASP.NET: Build Ultra-Fast and Ultra-Scalable web sites using ASP.NET and SQL Server

Quick Resource Box

• Fiddler PowerToy - Part 2: HTTP Performance
•  Fiddler
• ASP.NET Performance: Get Rid of HTTP 401 and HTTP 304
• Google adds site speed to search ranking

In the article Eric Lawrence, the author and the creator of the Fiddler tool, shares simple technique of adding custom rules that color outstanding request – be it improper caching or large payload.

Adding Custom Rules To Fiddler

I am using Fiddler v. 2.2.8.6. To add customer rules follow these steps:

• Click Rules in the menu.
• Click Customize Rules… or Ctrl+R.
• You should see CustomRules.js opened in Notepad.
• Scroll down to the line with the following function:

static function OnBeforeResponse(oSession: Session)

• Add the following lines to the function (taken from the article):

// Flag files over 25KB
   if (oSession.responseBodyBytes.length > 25000)
  {
      oSession["ui-color"] = "red";
      oSession["ui-bold"] = "true";
      oSession["ui-customcolumn"] = "Large file";
   }

// Mark files which do not have caching information
if (!oSession.oResponse.headers.Exists("Expires") &&
!oSession.oResponse.headers.Exists("Cache-Control"))
{
      oSession["ui-color"] = "purple";
      oSession["ui-bold"] = "true";
      oSession["ui-customcolumn"] = "Review Caching";
}

• Save the file by pressing Ctrl+S, and close the Notepad.

Testing Fiddler Custom Rules

To test the Fiddler custom rules just navigate to the site you want to inspect. Here is what I get after navigating the home page of my blog:

Highlighting potential performance problems helps quickly focus on it and start improving. Notice the request #3 colored in red – it exceeds 25 KB limit. Request #8 does not have caching header defined for it – colored in purple. Notice also the comments in Custom column. I could go further and and fine tune it, for example filter out 404, etc.

Conclusion and Recommendations

Recent announcement from Google that it incorporates performance into ranking algorithm makes the performance a serious  competitive advantage. I can easily imagine new breed Google performance consultants stealing a pie from SEO consultants. I guess it’d be a good move for any SEO consultant to get perf under their belt. Using Fiddler  makes it really easy.

Related Books

• Ultra-Fast ASP.NET: Build Ultra-Fast and Ultra-Scalable web sites using ASP.NET and SQL Server

Related Posts

• Free Web Performance Tools From Microsoft, Google, Yahoo, And IBM
• Improve Web Application Performance By Reducing Number Of Http Requests - Fiddler To The Rescue
• ASP.NET Performance Sin - Serving Images Dynamically (Or Another Reason To Love Fiddler)

Quick Resource Box

• patterns & practices summit – Israel 2010
• Slides from p&p summit Israel 2010
• Dissecting web app performance from browser through ASP.NET to IIS

Getting bigger servers does not always help achieving better performance. In fact, in many cases it even won't help at all. This session is prescriptive. It dissects canonical web application with performance scalpel revealing performance killers and boosters in browser, IIS, and .net code. You take away from this session performance principles, guidelines, samples, and tools that will help you plan, build and test your next mission-critical application.

The slides have been uploaded to skidrive. Enjoy.

Related Books

• Ultra-Fast ASP.NET: Build Ultra-Fast and Ultra-Scalable web sites using ASP.NET and SQL Server