SkyML: A MLaaS Federation Design for Multicloud-Based Multimedia Analytics

The advent of deep learning has precipitated a surge in public machine learning as a service (MLaaS) for multimedia analysis. However, reliance on a single MLaaS can result in product dependency and a loss of better performance offered by multiple MLaaSes. Consequently, many enterprises opt for an intercloud broker capable of managing jobs across various clouds. Though existing works explore the efficient utilization of inter-cloud computational resources and the enhancement of inter-cloud data transfer throughput, they disregard improving the overall accuracy of multiple MLaaSes. In response, we conduct a measurement study on object detection services, which are designed to identify and locate various objects within an image. We discover that combining predictions from multiple MLaaSes can improve analytical performance. However, more MLaaSes do not necessarily equate to better performance. Therefore, we propose SkyML, a user-side MLaaS federation broker that selects a subset of MLaaSes based on the characteristics of the request to achieve optimal multimedia analytical performance. Initially, we design a combinatorial reinforcement learning approach to select the sound MLaaS combination, thereby maximizing user experience. We also present an ingenious, automated taxonomy unification algorithm to minimize human efforts in merging MLaaS-specific labels into a user-preferred label space. Moreover, we devise an optimized ensemble strategy to aggregate predictions from the selected MLaaSes. Evaluations indicate that our similarity-based taxonomy unification approach can reduce annotation costs by 90%. Moreover, real-world trace-driven evaluations further prove that our MLaaS selection method can achieve similar levels of accuracy with a 67% reduction in inference fees.