Replay Debugging: The Future of Software Development

Possibly one of the coolest, and most relevant to the future of my field (software development) features that I had the opportunity to see at VMworld was Replay Debugging.  The feature is new and included as part of the just released VMware Workstation 6.5.  The feature is considered “experimental” and currently has its limits, but I personally feel that this is just the beginning of the next generation of software development.

So, what exactly is Replay Debugging?  It is a new feature that allows developers to debug recordings of programs that run inside virtual machines.  It can be extremely valuable in finding, diagnosing, and fixing bugs that would otherwise not easily be reproduced.  No need to “recreate” a bug, once it’s recorded, it can be replayed instruction by instruction how it happened when the error occurred.  This is ideal for non-deterministic bugs which only occur in very specific concurence of scenarios (threads, memory addresses, user behavior, etc.).  Consider “random” debug asserts, race conditions, and crashes that only happen once — and only on the QA person’s machine.

Want to know more?  Check out the ultimate resource at: replaydebugging.com.  The blog is created by E Lewis a software engineer at VMware working on the project.

Also, check out VMware’s community forum on the topic.

And finally…  VMware Workstation 6.5.