Cost-based Compute Cluster Formation in Edge Computing

Edge Computing (EC) is a promising computing paradigm that can foster a wide spectrum of delay-sensitive and/or data-intensive applications. As opposed to cloud computing, which relies on remote cloud servers, EC brings the computing service closer to the end-users, which can significantly reduce the delay. The concept of EC has recently expanded to include harvesting the computation resources of the Extreme Edge Devices (EEDs), such as smartphones, autonomous vehicles, tablets, etc. However, the cost of recruiting EEDs for resource allocation in such EC environments is mostly overlooked. In this paper, we propose the Price-based Compute Clusters Recruitment (PCCR) scheme. In PCCR, we minimize the cost of recruiting the EEDs required to perform a given set of tasks, where each task is satisfied by the collaborative effort of a group of EEDs forming a compute cluster. PCCR strives to minimize the total recruitment cost while keeping the delay below a certain threshold by forming the optimal set of compute clusters from a pool of heterogeneous EEDs available in a given geographical area. We formulate the optimization problem as a Mixed Integer Quadratically Constrained Quadratic Program (MIQCQP). We then derive an analytical solution using the KKT conditions and Lagrangian analysis. Extensive simulations show that PCCR significantly outperforms a prominent baseline approach in terms of recruitment cost.