Win with What You Have: QoS-Consistent Edge Services with Unreliable and Dynamic Resources

Mobile and energy harvesting devices increasingly provide resources for edge environments. These devices' mobility and limited energy budgets may cause failures and poor performance. The reliability and efficiency of edge services can be improved with equivalent microservices that satisfy application requirements by different means: execute equivalent microservices in the predefined patterns of fail-over to minimize execution costs or speculative parallelism to reduce latency. However, given the vast dissimilarities in resource availability and capability across edge environments, being limited to these predefined patterns when implementing edge services causes inconsistent QoS. To address this problem, we provide QoS-consistent edge services by customizing the execution of equivalent microservices. Our system estimates the environment-specific QoS of equivalent microservices and dynamically generates execution strategies that best satisfy given QoS requirements. We evaluate the effectiveness and performance of our system via simulations and benchmarks with realistic edge deployments. Our approach consistently out-performs the predefined execution patterns in satisfying the QoS requirements in unreliable and dynamic edge environments.