The goal of the Ajax View project is to improve developer's visibility into and control over their web applications' behaviors on end-user's desktops.

The Ajax View approach is to insert a server-side proxy (or web server plugin) in-between the web server machines and the end-user's browser. This proxy captures the web application's JavaScript code as it is being sent to a browser and rewrites the code to insert extra instrumentation code. The injected instrumentation code runs with the rest of the web application inside the end-user's browser and can capture performance, call graph, application state and user interaction information, providing visibility directly into the last hop of the user's experience.

Because Ajax View is rewriting web application code dynamically each time a user visits the web site, it can:

1. serve different instrumentation code to different users. This allows us to distribute instrumentation code across many users, spreading the cost of gathering lots of information such that no single user pays a high performance penalty.
2. adapt an instrumentation policy and serve different instrumentation code over time. For example, we can drill-down into performance problems and gather extra context about bugs

Download the first release of our client-side prototype. The prototype requires Windows Vista, Windows 2003, or Windows XP SP2.

We've written up a short usage document, showing a simple walkthrough Ajax View's performance profiling.

Contact us by sending an email to emrek@microsoft.com and livshits@microsoft.com

• Emre Kıcıman
• Ben Livshits
• Himanshu Sharma (intern, summer 2006)

• AjaxScope: A Platform for Remotely Monitoring the Client-side Behavior of Web 2.0 Applications Emre Kıcıman and Ben Livshits. To appear in Proceedings of the 21st ACM Symposium on Operating Systems Principles (SOSP'07), Oct 2007, Stevenson, WA.  [PDF]
• Live Monitoring: Using Adaptive Instrumentation and Analysis to Debug and Maintain Web Applications, Emre Kıcıman and Helen Wang. In Proceedings of the 11th Workshop on Hot Topics in Operating Systems (HotOS XI), San Diego, CA, May 2007.  [PDF]