Product Reviews

Locating the Weakest Link

AppSight 4.0 maintains watch over events that may be making your application crumble.

• By Mike Gunderloy
• 11/20/2002

Installing the software was trivial; basically just a matter of putting in the CDs and accepting all the defaults. This left me with the underlying "Black Box" technology for watching applications, the Black Box Manager to control the Black Boxes, and an integrated set of consoles (rich GUI applications) for analyzing the results. Then comes the process of watching a failing application. Basically, identify what you want to watch, run it, look at the results in the consoles.

And wow, what a lot of results you can get. Object creation and destruction, strings of data sent between components, database accesses, library loads, memory allocations...damned near anything. There are some pretty amazing things they can do here. For example, deploy black boxes on all three tiers of an application that uses a web browser to access a database via an IIS server. Run the browser and look at the details of the capture in the console. Spot a problem, click a few times...and be looking at what happened on the IIS server. Click a few more...and you're right over on the database server looking at what it was doing.

After seeing some of the canned examples, I deployed the technology to a Web server where I was having a mystery problem. This server wasn't on my domain, but no problem - you can deploy a Black Box with a simple Web or disk-based install, and capture its results to a log file for later analysis (and the log files are amazingly small, even when they're capturing everything the user does on the screen for later playback). A few minutes later I was looking at the trace in the console, and quickly found the web page that was causing the problem and the Windows library where things were blowing up.

One more example of what the software can do: you identify a set of PerfMon counters that you'd like to track. Run the application. Then look at the counter values in a graph, like the one that PerfMon displays...only you can scroll back and forth over the entire lifetime of the application, rather than having a circular buffer overwrite itself. And as you scroll, the list of application events stays synchronized. Locating the code that was running when memory leaked becomes trivial with this model.

Yes, it's high-priced, but this is darned good software. If I were running a dev group producing a serious commercial product, or distributed apps for a decent-sized corporation, I'd certainly be fighting to buy a copy.