Exclusive: AppSight gets the bugs out of your apps

Two of the most time-consuming aspects of debugging software are reproducing the problem and locating the cause of the bug. And as software becomes more complex -- with Web services integrating business processes and desktop environments moving to multithreaded software -- merely reproducing a bug can be a big project. If the developer cannot duplicate the event, though, resolving it is well-nigh impossible.

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What developers need is a detailed log that records all events in a program’s execution, so a record exists when an anomaly occurs. Unfortunately, logging mechanisms often end up as home-grown, in-house systems based on tracing operations that typically record insufficient information and often change the behavior of the programs they monitor.

AppSight 6.0, from BMC/Identify (BMC bought Identify, the original developer of AppSight), is an extraordinary product that elegantly addresses the problems of reproducing and tracking down bugs. It is a tool that almost every developer will want to have, but one that I fear few will be able to afford.

Black boxes for all

AppSight uses logging software called Black Boxes that run on the systems to be monitored. These preconfigured installations can record almost every event on the host system, including network operations, file accesses, DLL loads and component accesses, mouse clicks and movements, video capture, and a slew of performance metrics.

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On systems with accessible Microsoft .pdb files (generated at compilation), the Black Box maps events directly to individual lines of source code. A separate Black Box for J2EE systems performs similar logging; however, it drills down only to the class level.

Captured data is saved to a circular buffer -- that is, you pre-set the total amount of data you want to capture and the BlackBox will always capture exactly that much, overwriting older items when it runs out of room.

Beyond events, Black Boxes meticulously record system status. Virtually everything that is knowable about the hardware and software running at log time is captured by the Black Boxes, including version numbers of DLLs that can be crucial to isolating configuration issues.

Black Boxes are free -- you may use as many or as few as you wish. Preconfigured Black Boxes for various enterprise applications are available on the AppSight customer Web site. The boxes are coordinated by AppSight server software (included as part of the deployment), which acts as a repository for the logs and as a remote configuration tool for deployed boxes.

What you pay for are the consoles in which logged data is replayed. This is where all the magic occurs. And magic is the right word: When replaying a log, one console window shows exactly what the end-user saw, and the window below it displays the corresponding program events.