Fair and Efficient Online Adaptive Scheduling for Multiple Sets of Parallel Applications

Both fairness and efficiency are crucial measures for the performance of parallel applications on multiprocessor systems. In this paper, we study online adaptive scheduling for multiple sets of such applications, where each set may contain one or more jobs with time-varying parallelism profile. This scenario arises naturally when dealing with several applications submitted simultaneously by different users in a large parallel system, where both user-level fairness and system-wide efficiency are important concerns. To achieve fairness, we use the equipartitioning algorithm, which evenly splits the available processors among the active job sets at any time. For efficiency, we apply a feedback-driven adaptive scheduler, which periodically adjusts the processor allocations within each set by consciously exploiting the jobs' execution history. We show that our algorithm is competitive for the objective of minimizing the set response time. For sufficiently large jobs, this theoretical result improves upon an existing algorithm that provides only fairness but lacks efficiency. Furthermore, we conduct simulations to empirically evaluate our algorithm, and the results confirm its improved performance using malleable workloads consisting of a wide range of parallelism variation structures.