A QoS-Oriented External Scheduler



Quality of Service (QoS) related objectives are used in many current applications, like grid-based systems and e-commerce applications. Network managers, application servers and grid resource managers are examples of software that is often QoS-enabled. On the other hand, database servers usually provide a best-effort model, answering each query as fast as possible. Thus, they are not prepared to provide QoS differentiation for incoming queries. In this work, we present an external control system for QoS-oriented scheduling of database requests. Our external system prioritizes queries and automatically adjusts the number of queries that are concurrently executed (degree of multi-programming) in order to achieve user-specified Service Level Objectives (SLO). There are works on external schedulers, admission control systems and on the specification of the degree of multi-programming, but most focus on best-effort models and do not consider Service Level Objectives. Our experimental results show that our approach is effective and that using a specialized scheduler for achieving SLO is very important.


QoS, query scheduling, external database scheduler


QoS-oriented external scheduler


23rd Annual ACM Symposium on Applied Computing (ACM SAC 2008), March 2008

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