Distributed Logging System for ROS-Based Systems

The Robot Operating System (ROS) is a widely-used development and service platform for robot clusters and autonomous driving systems. ROS provides a data logging tool named ROSBAG to record and play back messages between processes into permanent storage devices. Despite of its excellent functionality for distributed communication, only a single logging node is allowed to gather data streams. Although such a single node logging is only appropriate for small systems, it does not have the capability to deal with big data distributed systems. In this paper, we present a distributed logging system for ROS-based systems. We wrapped ROSBAG tools with a Python-based parallel ssh tool - pssh to send commands to start and stop logging. We also supported a synchronous replay method to play back the data streams separately stored in several storage devices. Our mechanism can evenly distribute bandwidth consumption of storage and networks for collecting and storing data. It also disperses the logging data into the storage devices in several computers and improves the available logging duration previously restricted by storage capacity.