Shaik Mohammed Salman's PhD Defense

2024/10/23

Shaik Mohammed Salman, ARRAY++ Phd student will defend his PhD thesis on 5th November at 13:15 in Västerås Campus

Title: Scheduling and Dispatching Strategies for Real-Time Applications in Multi-Server Systems

Date and time: November 5th, 2024, 13:15

Room: Kappa (Västerås Campus)

Opponent: Marko Bertogna, Professor, University of Modena and Reggio Emilia, Italy.

Committee:

Johan Eker, Professor, Lund University, Sweden

Risat Pathan, Associalte Professor, Chalmers University of Technology, Sweden

Dakshina Dasari, PhD, Robert Bosch GmbH, Germany

Professor Mats Björkman, Professor, Mälardalen University, Sweden (reserve)

Advisors:

Thomas Nolte, Professor, MDU

Alessandro Papadopoulos, MDU

Saad Mubeen, MDU

Abstract:

Real-time systems are central components in, e.g., industrial robots and automated guided vehicles, which integrate a wide range of algorithms with varying levels of timing requirements to achieve their functional behavior. Historically, in certain systems, these algorithms were deployed on dedicated single core hardware platforms that exchanged information over a real-time network, while more recent designs have adapted an integrated architecture where these algorithms are executed on an embedded multi-core hardware platform. Meanwhile, the advantages provided by cloud and fog architectures for non-real time applications have prompted discussions about the possibility of achieving similar benefits for systems such as industrial robot controllers. This thesis addresses a subset of challenges related to scheduling to facilitate this transition, and presents three main contributions aimed at improving online scheduling approaches in multi-server systems for applications with real-time requirements. First, an approach based on minimum parallelism reservations is proposed for scheduling sequential tasks in hierarchical multi-server systems with clairvoyant inputs, ensuring adherence to hard real-time requirements. Second, a framework is introduced that utilizes estimated processing times to enhance average throughput in distributed multi-queue multi-server systems while managing tasks with stochastic inputs and firm real-time requirements, thereby improving resource utilization. Finally, competitive algorithms are proposed that leverage estimated processing times to minimize average (modified) tardiness in centralized single-queue multi-server systems, addressing the scheduling of sequential tasks with arbitrary arrivals and soft real-time requirements. Collectively, these contributions establish a robust foundation for improving the performance of real-time systems operating in increasingly complex environments characterized by dynamic workloads and varying resource availability.