TA1948

Reverse and Replay-Based Debugging

Identifying, understanding, and correcting bugs is a critical and
unavoidable aspect of all large software development projects.
Unfortunately, the debugging process is notoriously challenging, because
many bugs "hide" (i.e., they manifest in one run of a program but not
the next). Naturally, it's difficult to fix a bug that a developer
cannot even observe, so this class of bugs represent a
disproportionately large portion of development costs.
VMware, Inc. is experimenting with a new feature called Replay-Based
Debugging to address this challenge. Replay-Based Debugging uses
VMware's Record/Replay technology to record all activity within a
virtual machine. A recording can be replayed repeatedly with
identical behavior each time, and applications running in a recording
can be debugged (i.e., inspected and controlled) using Microsoft
Visual Studio. Replay-based debugging improves the debugging
experience in the following ways. i) Once recorded, the
manifestation of a bug can't hide. (ii) The debugging process does
not interfere with the subject program (e.g., change its timing
characteristics), because the recorded form of the program is
debugged. (iii) We've built an abstraction of "reverse execution"
allowing programmers to logically execute backward until a control or
data breakpoint is encountered.

Technical Overview Session

Networking; Storage / Backup; VMware Infrastructure; Virtualization Platform / Hypervisor

1 Hour

E Lewis( VMware,Inc. ), Rama Iyengar( VMware, Inc. )

Rama Iyengar is an MTS at VMware. Prior to this she worked on various aspects of browser security at GreenBorder Technologies, Inc., an enterprise security software company that is now a part of Google.
She completed her post-graduate work at Cal State East Bay (formerly Cal State Hayward).

E Lewis is Staff Engineer in the Advanced Development Group at VMware,
Inc., where he is exploring new technologies in the implementation and
application of virtual machines. Before joining VMware, Inc. in January 2007,
Dr. Lewis was Assistant Professor in the Department of Computer and
Information Science at the University of Pennsylvania in
Philadelphia.