Shedding Light on Distributed System Executions

In a distributed system, the hosts execute concurrently, generating asynchronous logs that are challenging to comprehend. We present two tools: ShiVector to transparently add vector timestamps to distributed system logs, and ShiViz to help developers understand distributed system logs by visualizing them as space-time diagrams. ShiVector is the first tool to offer automated vector timestamp instrumentation without modifying source code. The vector-timestamped logs capture partial ordering information, useful for analysis and comprehension. ShiViz space-time diagrams are simple to understand and interactive - the user can explore the log through the visualization to understand complex system behavior. We applied ShiVector and ShiViz to two systems and found that they aid developers in understanding and debugging.