The Effect of Real Workloads and Synthetic Workloads on the Performance of Job Scheduling for Non-Contiguous Allocation in 2D Mesh Multicomputers

2015 ◽  
Vol 6 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Saad Bani-Mohammad
Keyword(s):  
System Performance ◽  
Job Scheduling ◽  
Allocation Strategy ◽  
Extensive Simulation ◽  
Scheduling Strategy ◽  
Need To Evaluate ◽  
Scheduling Strategies ◽  
Simulation Results ◽  
Allocation Algorithms ◽  
Workload Models

The performance of non-contiguous allocation has been traditionally carried out by means of simulations based on synthetic workloads, and also it can be significantly affected by the job scheduling strategy used for determining the order in which jobs are selected for execution. To validate the performance of the non-contiguous allocation algorithms, there has been a need to evaluate the algorithm's performance based on a real workload trace. In this paper, the performance of the well-known Greedy Available Busy List (GABL) non-contiguous allocation strategy for 2D mesh-connected multicomputers is revisited considering several important job scheduling strategies based on a real workload trace, and the results are compared to those obtained from using a synthetic workload. The scheduling strategies used are the First-Come-First-Served (FCFS), Out-of-Order (OO), and Window-Based job scheduling strategies. These strategies have been selected because they are common and they have been used in related works (Ababneh & Bani-Mohammad, 2011). Extensive simulation results based on synthetic and real workload models indicate that the Window-Based job scheduling strategy can improve both overall system performance and fairness (i.e., maximum job waiting delays) by adopting a large job scheduling window. Moreover, the relative performance merits of the scheduling strategies when a real workload trace is used are in general compatible with those obtained when a synthetic workload is used.

Submesh Allocation in 3D Mesh Multicomputers Using Free Lists

2015 ◽  
pp. 171-187
Author(s):  
Saad Bani-Mohammad ◽  
Ismail Ababneh ◽  
Motasem Al Smadi
Keyword(s):  
Job Scheduling ◽  
Substantial Effect ◽  
Allocation Strategy ◽  
3D Mesh ◽  
Extensive Simulation ◽  
System Utilization ◽  
Service Demand ◽  
Extensive Evaluation ◽  
Simulation Results ◽  
Allocation Strategies

This chapter presents an extensive evaluation of a new contiguous allocation strategy proposed for 3D mesh multicomputers. The strategy maintains a list of maximal free sub-meshes and gives priority to allocating corner and boundary free sub-meshes. This strategy, which we refer to as Turning Corner-Boundary Free List (TCBFL) strategy, is compared, using extensive simulation experiments, to several existing allocation strategies for 3D meshes. In addition to allocation strategies, two job scheduling schemes, First-Come-First-Served (FCFS) and Shortest-Service-Demand (SSD) are considered in comparing the performance of the allocation strategies. The simulation results show that TCBFL produces average turnaround times and mean system utilization values that are superior to those of the existing allocation strategies. The results also reveal that SSD scheduling is much better than FCFS scheduling. Thus, the scheduling and allocation strategies both have substantial effect on the performance of contiguous allocation strategies in 3D mesh-connected multicomputers.

Corner-Boundary Processor Allocation for 3D Mesh-Connected Multicomputers

2015 ◽  
Vol 5 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Ismail M. Ababneh ◽  
Saad Bani-Mohammad ◽  
Motasem Al Smadi
Keyword(s):  
System Performance ◽  
Allocation Strategy ◽  
Processor Allocation ◽  
Simulation Experiments ◽  
3D Mesh ◽  
Extensive Simulation ◽  
System Utilization ◽  
Free List ◽  
Simulation Results ◽  
Allocation Strategies

This research paper presents a new contiguous allocation strategy for 3D mesh-connected multicomputers. The proposed strategy maintains a list of maximal free sub-meshes and gives priority to allocating corner and boundary free sub-meshes. The goal of corner and boundary allocation is to decrease the number of leftover free sub-meshes and increase their sizes, which is expected to reduce processor fragmentation and improve overall system performance. The proposed strategy, which is referred to as Turning Corner-Boundary Free List (TCBFL) strategy, is compared, using extensive simulation experiments, to several existing allocation strategies for 3D meshes. These are the First-Fit (FF), Turning First-Fit Free List (TFFFL), and Turning Busy List (TBL) allocation strategies. The simulation results show that TCBFL produces average turnaround times and mean system utilization values that are superior to those of previous strategies.

An Efficient All Shapes Busy List Processor Allocation Algorithm for 3D Mesh Multicomputers

2017 ◽  
Vol 7 (2) ◽  
pp. 10-26 ◽  
Author(s):  
Saad Bani-Mohammad
Keyword(s):  
System Performance ◽  
Turnaround Time ◽  
Allocation Strategy ◽  
Processor Allocation ◽  
3D Mesh ◽  
System Utilization ◽  
Size And Shape ◽  
Shape Constraint ◽  
Scheduling Strategies ◽  
Allocation Strategies

Contiguous processor allocation is useful for security and accounting reasons. This is due to the allocated jobs are separated from one another, where each sub-mesh of processors is allocated to an exclusive job request, and the allocated sub-mesh has the same size and shape of the requested job. The size and shape constraint leads to high processor fragmentation. Most recent contiguous allocation strategies suggested for 3D mesh-connected multiconputers try all possible orientations of an allocation request when allocation fails for the requested orientation, which reduces processor fragmentation and hence improves system performance. However, none of them considers all shapes of the request in the process of allocation. To generalize this restricted rotation, we propose, in this paper, a new contiguous allocation strategy for 3D mesh-connected multicomputers, referred to as All Shapes Busy List (ASBL for short), which takes into consideration all possible contiguous request shapes when attempting allocation for a job request. ASBL depends on the list of allocated sub-meshes, in the method suggested in (Bani-Mohammad et al., 2006), for selecting an allocated sub-mesh. The performance of the proposed ASBL allocation strategy has been evaluated considering several important scheduling strategies under a variety of system loads based on different job size distributions. The simulation results have shown that the ASBL allocation strategy improves system performance in terms of parameters such as the average turnaround time of jobs and system utilization under all scheduling strategies considered.

scholarly journals Hybrid Chirp Signal Design for Improved Long-Range (LoRa) Communications

Signals ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 1-10
Author(s):  
Md. Noor-A-Rahim ◽  
M. Omar Khyam ◽  
Apel Mahmud ◽  
Xinde Li ◽  
Dirk Pesch ◽  
...  
Keyword(s):  
Long Range ◽  
Bit Error Rate ◽  
Modulation Scheme ◽  
Signal Design ◽  
Chirp Signal ◽  
Performance Gain ◽  
Extensive Simulation ◽  
Noise Interference ◽  
Chirp Signals ◽  
Simulation Results

Long-range (LoRa) communication has attracted much attention recently due to its utility for many Internet of Things applications. However, one of the key problems of LoRa technology is that it is vulnerable to noise/interference due to the use of only up-chirp signals during modulation. In this paper, to solve this problem, unlike the conventional LoRa modulation scheme, we propose a modulation scheme for LoRa communication based on joint up- and down-chirps. A fast Fourier transform (FFT)-based demodulation scheme is devised to detect modulated symbols. To further improve the demodulation performance, a hybrid demodulation scheme, comprised of FFT- and correlation-based demodulation, is also proposed. The performance of the proposed scheme is evaluated through extensive simulation results. Compared to the conventional LoRa modulation scheme, we show that the proposed scheme exhibits over 3 dB performance gain at a bit error rate of 10−4.

scholarly journals Game-based cache allocation strategy for ICN slicing

2021 ◽  
Vol 336 ◽  
pp. 05030
Author(s):  
Liping Ge ◽  
Jinhe Zhou
Keyword(s):  
Equilibrium Solution ◽  
Base Station ◽  
Virtual Network ◽  
Game Model ◽  
Allocation Strategy ◽  
Newton Iterative Method ◽  
Content Acquisition ◽  
Simulation Results ◽  
Cache Allocation ◽  
Cooperative Game Model

To reduce the delay of content acquisition, this paper proposes a game-based cache allocation strategy in the Information-Centric Network (ICN) slice. The cache resource allocation of different mobile virtual network operators (MVNOs) is modeled as a non-cooperative game model. The Newton iterative method is used to solve this problem, and the cache space allocated by the base station for each MVNO is obtained. Finally, the Nash equilibrium solution is obtained. Simulation results show that the proposed algorithm can reduce the delay.

Fuzzy Logic Controller for Force Feedback Control of Quadcopter via Tether

2020 ◽  
Author(s):  
Bennett Breese ◽  
Drew Scott ◽  
Shraddha Barawkar ◽  
Manish Kumar
Keyword(s):  
Fuzzy Logic ◽  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Force Feedback ◽  
Power Transmission ◽  
Extensive Simulation ◽  
Control Scheme ◽  
Area Surveillance ◽  
Simulation Results ◽  
Long Endurance

Abstract Tethered drone systems can be used to perform long-endurance tasks such as area surveillance and relay stations for wireless communication. However, all the existing systems use tethers only for data and power transmission from a stationary point on the ground. This work presents a control strategy that enables a quadcopter to follow a moving tether anchor. A force feedback controller is implemented using Fuzzy Logic. Using force-based strategy provides effective compliance between the tether’s anchor and the drone. The drone can thus be controlled by mere physical movement/manipulation of tether. This enhances the safety of current tethered drone systems and simplifies the flying of drones. Fuzzy Logic provides an intuitive edge to the control of such systems and allows handling noise in force sensors. Extensive simulation results are presented in this paper showing the effectiveness of the proposed control scheme.

scholarly journals Dynamic Job Scheduling Strategy Using Jobs Characteristics in Cloud Computing

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1638 ◽  
Author(s):  
Mohammed A. Alsaih ◽  
Rohaya Latip ◽  
Azizol Abdullah ◽  
Shamala K. Subramaniam ◽  
Kamal Ali Alezabi
Keyword(s):  
Execution Time ◽  
Job Scheduling ◽  
Scheduling Algorithm ◽  
Job Characteristics ◽  
Available Bandwidth ◽  
Scheduling Strategy ◽  
Cloud Users ◽  
Performance Variations ◽  
Available Resources

A crucial performance concern in distributed decentralized environments, like clouds, is how to guarantee that jobs complete their execution within the estimated completion times using the available resources’ bandwidth fairly and efficiently while considering the resource performance variations. Formerly, several models including reservation, migration, and replication heuristics have been implemented to solve this concern under a variety of scheduling techniques; however, they have some undetermined obstacles. This paper proposes a dynamic job scheduling model (DTSCA) that uses job characteristics to map them to resources with minimum execution time taking into account utilizing the available resources bandwidth fairly to satisfy the cloud users quality of service (QoS) requirements and utilize the providers’ resources efficiently. The scheduling algorithm makes use of job characteristics (length, expected execution time, expected bandwidth) with regards to available symmetrical and non-symmetrical resources characteristics (CPU, memory, and available bandwidth). This scheduling strategy is based on generating an expectation value for each job that is proportional to how these job’s characteristics are related to all other jobs in total. That should make their virtual machine choice closer to their expectation, thus fairer. It also builds a feedback method which deals with reallocation of failed jobs that do not meet the mapping criteria.

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