Significant time is spent by companies trying to reproduce and fix the bugs that occur for released code. To assist developers, we propose the BugNet architecture to continuously record information on production runs. The information collected before the crash of a program can be used by the developers working in their execution environment to deterministically replay the last several million instructions executed before the crash. BugNet is based on the insight that recording the register file contents at any point in time, and then recording the load values that occur after that point can enable deterministic replaying of a program’s execution. BugNet focuses on being able to replay the application’s execution and the libraries it uses, but not the operating system. But our approach provides the ability to replay an application’s execution across context switches and interrupts. Hence, BugNet obviates the need for tracking program I/O, interrupts and DMA transfers, which wo...