dynaTrace Ajax Edition: tracing JS performance

September 30, 2009 11:27 pm | 4 Comments

DynaTrace has been around for several years focusing on the performance analysis of backend applications. They entered the frontend performance arena last week with the release of dynaTrace Ajax Edition. It’s a free tool that runs in IE as a browser helper object (BHO). I tried it out and was pleased. It’s important to have development tools that work in IE. I love Firefox and all its add-ons, but I also know how important it is to test on IE and more importantly to be able to debug on IE.

Once you’ve downloaded and installed DAE (my shorthand name for dynaTrace Ajax Edition), don’t be fooled if you don’t see an easy way to start it from within IE. You have to go under Programs in the Start Menu and find the dynaTrace program group. Entering a URL for the first test run is obvious. For subsequent runs, click on the “play” icon’s menu and pick “New Run Configuration…” and enter a different URL. One of the nice features of DAE is that it can run during a multi-page workflow. You can enter the starting URL, and then navigate to other pages or launch Ajax features while DAE monitors everything in the background. When you close IE you can dig into all the info DAE has gathered.

DAE gathers a ton of information on your web app. My main issue is that there’s so much information you really need to play with it for awhile to discover what it can do. This isn’t a bad thing – slightly challenging at the beginning, but once you know how to navigate through the UI you’ll find the answer for almost any performance or profiling question you have. I kept finding new windows that revealed different views of the information DAE had collected.

The main differentiator of DAE is all the JavaScript profiling it does. Time is broken out in various ways including by event triggers and by JavaScript API (libraries). It has an HTTP waterfall chart. A major feature is the ability to save the DAE analysis, so you can examine it later and share it with colleagues. There are other features that are more subtle, but pleasant to run into. For example, DAE automatically UNminifies JavaScript code, so you can look at a prettified version when debugging a live site.

When it comes to analyzing your JavaScript code to find what’s causing performance issues, dynaTrace Ajax Edition has the information to pinpoint the high-level area all the way down to the actual line of code that needs to be improved. I recommend you give it a test run and add it to your performance tool kit.