Popis: |
Networked embedded software systems incorporate varying degrees of adaptation behavior to sustain their operations with acceptable quality of service (QoS), in the face of hostile external events (e.g., resource outages in a cloud, road slipperiness faced by cars). A highly agile cruise control system of a car, for e.g., may dynamically adjust its controller parameters to generate a higher-than-normal increase in torque when encountering a higher road elevation (relative to a basic controller). With the high complexity of such dynamic adaptive systems, their QoS capability depends on how well they respond to hostile external events in meeting QoS specs. We benchmark the QoS capability of a networked system by a stress-testing a simulation model of the system with artificially injected environment conditions (such as road elevation and message loss). As a case study, we describe the QoS assessment of a multi-vehicle adaptive cruise control system. |