Overload Protection of Cloud-IoT Applications by Feedback Control of Smart Devices.

One of the most common usage scenarios for Cloud-IoT applications is Sensing-as-a-Service, which focuses on the processing of sensor data in order to make it available for other applications. Auto-scaling is a popular runtime management technique for cloud applications to cope with a varying resource demand by provisioning resources in an autonomous manner. However, if an auto-scaling system cannot provide the required resources, e.g., due to cost constraints, the cloud application is overloaded, which impacts its performance and availability. We present a feedback control mechanism to mitigate and recover from overload situations by adapting the send rate of smart devices in consideration of the current processing rate of the cloud application. This mechanism supports a coupling with the widely used threshold-based auto-scaling systems. In a case study, we demonstrate the capability of the approach to cope with overload scenarios in a realistic environment. Overall, we consider this approach as a novel tool for runtime managing cloud applications.