Service control with the preemptive parallel job scheduler Scojo-PECT

Abstract

User satisfaction and scheduling on grids makes predictability of response times and quality-of-service highly desirable. However, existing approaches for response-time prediction still show significant prediction errors, mostly due to problems in dynamic arrival of jobs with potentially higher priority and hard-to-anticipate packing and backfilling effects. The same problems imply that quality-of-service cannot be solved with standard approaches from communication systems. Thus, this paper presents a scheduling approach which provides a more suitable framework for service guarantees and predictability. The approach is based on coarse-grain preemption, combined with an innovative separation of job classes. Resource shares can be determined as necessary to meet target service levels. A further extension permits limited dynamic resource allocation to adapt to variations in machine load and job mixes. The feasibility of service control is demonstrated with various workloads.