A lot of research works have been done in this filed of real-time database systems to seek for optimizing transaction scheduling. The findings of such studies examining the use of various algorithms of priority assignment policy have been discussed widely. One drawback of these approaches is presenting poor performance due to neglect repetitively missed real-time transactions. In this paper, an...

Priority scheduling for packets is a hot topic, as interactive (voice,video) services are being integrated in existing data networks. In this paper, we consider a discrete-time queueing system with nonpreemptive (or Head-Of-the-Line) priority scheduling and a general number of priority classes. Packets of variable length arrive in the queueing system. We derive expressions for the probability g...

We present an idling, dynamic priority scheduling policy for non-preemptive task sets with precedence, wait constraints, and deadline constraints. The policy operates on a well-formed task model where tasks are related through a hierarchical temporal constraint structure found in many real-world applications. In general, the problem of sequencing according to both upperbound and lowerbound temp...

This paper proposes an efficient priority assignment algorithm for fixed priority preemption threshold scheduling (PTS), which we named FAST-TRAVERSE. It is optimal in the sense that it always finds a feasible priority assignment if one exists. While there are existing optimal algorithms, they are inefficient to be used in practice. The key ideas of FAST-TRAVERSE are to prune sibling traverses ...

Dynamic Priority Time Petri Nets (dPTPN) represent a powerful formalism for the scheduling analysis of Real-Time Systems running on Multiprocessor architecture. The originality of the dPTPN semantics, compared to the existing research work, is the dynamic calculation of the priority of transitions in conflict. The present paper presents a new modeling strategy with dPTPN based on object modelin...

In this thesis we address the problem of fair and priority scheduling. We focus our attention on systems characterized by an infinite computation, a discrete decomposition of tasks into atomic operation and a known-a-priori set of precedence-constraints among the activities to be performed. We analyze two fairness and two priority specifications related to the frequency of occurrence of activit...

This study addresses a two-tier job scheduling problem for SaaS cloud service providers which rely on resources leased from IaaS cloud providers to achieve elasticity to computational power. In our model, a project represents a user request which consists of multiple jobs; the SaaS is obligated to complete projects using multiple resources leased from IaaS or PaaS providers. The goals are to re...

Priority scheduling for packets is a hot topic, as interactive (voice,video) services are being integrated in existing data networks. In this paper, we consider a discrete-time queueing system with a non-preemptive (or Head-Of-the-Line) priority scheduling discipline and a general number of priority classes. Packets of variable length arrive in the queueing system. We derive expressions for the...

In this paper, we consider a discrete-time queueing system with head-of-line (HOL) priority. First, we will give some general results on a GI-1-1 queue with priority scheduling. In particular, we will derive expressions for the Probability Generating Function of the system contents and the cell delay. Some performance measures (such as mean, variance and approximate tail distributions) of these...

Modern safety-critical systems, such as avionics, tend to be mixed-critical, because integration of different tasks with different assurance requirements can effectively reduce their costs. Scheduling is one of the main challenges of such systems. In this work we show that a generalization of the Time Triggered (TT) scheduling paradigm, Single Time Table per Mode (STTM) dominates other approach...