Abstract
In Real Time System, the achievement of deadline is the main target of every scheduling algorithm. Earliest Deadline First (EDF), Rate Monotonic (RM), and least Laxity First are some renowned algorithms that work well in their own context. As we know, there is a very common problem Domino's effect in EDF that is generated due to overloading condition (EDF is not working well in overloading situation). Similarly, performance of RM is degraded in underloading condition. We can say that both algorithms are complements of each other. Deadline missing in both events happens because of their utilization bounding strategy. Therefore, in this paper we are proposing a new scheduling algorithm that carries through the drawback of both existing algorithms. Joint EDF-RM scheduling algorithm is implemented in global scheduler that permits task migration mechanism in between processors in the system. In order to check the improved behavior of proposed algorithm we perform simulation. Results are achieved and evaluated in terms of Success Ratio (SR), Average CPU Utilization (ECU), Failure Ratio (FR), and Maximum Tardiness parameters. In the end, the results are compared with the existing (EDF, RM, and D_R_EDF) algorithms. It has been shown that the proposed algorithm performs better during overloading condition as well in underloading condition.
Highlights
Introduction and MotivationReal Time Distributed System is a distributed system with real time properties
After simulating thousands of tasks, we find that Earliest Deadline First (EDF), Rate Monotonic (RM) and D R EDF scheduling algorithms’ Success ratio can vary we sometimes find that our proposed algorithm has a higher Success Ratio than the existing algorithms (Figure 11)
Proposed scheduling algorithm is the combination of EDF and RM scheduling algorithms that rise above the overloading problem of any processor
Summary
Real Time Distributed System is a distributed system with real time properties. We can say that RTDS is a combination of RTS and distributed system (Figure 1). Based on the execution of real time task RTS falls into the following categories. EDF, RM, and Least Laxity First are some basic scheduling algorithms that execute real time tasks on the basis of their deadline, interarrival period, tardiness, and so forth. Task duplication method is given on the basis of computation to communication ratio (CCR) in between processors This technique is mostly applicable on dependent tasks (DAG) in order to balance the load as well as minimize the execution cost of complete DAG [14, 15]. Tasks in a distributed system are assigned to processors by using the following schedulers (Figure 2). (b) real time task execution on allotted processors of distributed system (including task migration).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
