Efficient online validation with delta execution

Software systems are constantly changing. Patches to fix bugs and patches to add features are all too common. Every change risks breaking a previously working system. Hence administrators loathe change, and are willing to delay even critical security patches until after fully validating their correctness. Compared to off-line validation, on-line validation has clear advantages since it tests against real life workloads. Yet unfortunately it imposes restrictive overheads as it requires running the old and new versions side-by-side. Moreover, due to spurious differences (e.g. event timing, random number generation, and thread interleavings), it is difficult to compare the two for validation. To allow more effective on-line patch validation, we propose a new mechanism, called delta execution, that is based on the observation that most patches are small. execution merges the two side-by-side executions for most of the time and splits only when necessary, such as when they access differen...

• Type: Conference
• Year: 2009
• Where: ASPLOS
• Authors: Joseph Tucek, Weiwei Xiong, Yuanyuan Zhou
• Keywords: ASPLOS 2009, On-line Patch Validation, On-line Validation, Programming Languages, Spurious Differences