Cloud computing provides a flexible way to access data from anywhere. The efficiency of the cloud has been driven in part by virtualization and it allows two or more operating systems on one PC. Virtualization assists in effective resource utilization and builds an effective system. This technology enables the service providers to provide VM (Virtual Machine) for work other than physical server machines. VM provides mobility and flexibility over easy migration that enables VMs dynamic mapping to available resources. In a cloud environment, the scheduling task is a challenging task. This technique is used to allocate certain jobs to particular resources at a particular time. The main aim of this strategy is to reduce execution time and less response time.
For the purposes of scheduling the tasks, many algorithms were found to be used predominantly throughput the literature. Some of those algorithms were: GA – Genetic Algorithm, PSO – Particle Swarm Optimization, CS – Cuckoo Search Algorithm and ACO - Ant Colony Optimization.
To face more user’s task requests, the cloud data centres not only finished the designated large tasks but also it was able to satisfy service requirements of the users [1]. In order to divide the systems’ resources and proceed with scheduling, it was important to solve the problems in cloud computing. Quality of service was mainly related in allocating the goal of scheduling. By implementing price model in scheduling algorithm, it was possible to detect multiple targets and also the service cost optimization was found to be depended on PSO-Particle Swarm Optimization. PSO algorithm was found to use dynamic cloud environment that minimizes the task completion time, in turn reduces user’s task cost.
GA-Genetic Algorithm and PSO were combined by a novel hybrid meta-heuristic method [2] for the tasks presented in directed acyclic graph that were showing the communication each inter-tasks. This proposed meta-heuristic methodology was different from the earlier hybrid meta-heuristics concepts which stand apart by improving the PSO-GA solution. PSO was mainly used to for the sake of diversifying and GA was adapted for the sake of intensifying the process in this meta-heuristic methodology. The PSO-GA consisted two standard tasks in it for scheduling the problem of linear algebra with the Elimination of Gauss-Jordan and decomposition of LU. This PSO-GA was performance wise better than other compared methods. The scheduling operations were being carried out in cloud computing environments to provision the Dynamic on-demand resource [3]. Delegation of tasks for virtual machines (VM) were done by task scheduling with the help of a nondeterministic polynomial, which increases the performance and usability, thereby, decreasing the time of response and maintains the balance of the entire system. When introducing a method of static typed task scheduling depending upon the algorithm of PSO, the designated tasks will be independent. This work performance was majorly based on the technique of load maintenance. This devised methodology of scheduling the task was validated with the round robin type of scheduling the task, enhanced scheduling of task by PSO along with the instance of load balancing. The outcomes reveal that this PSO based scheduling of the task outperforms the compared existing algorithms. This work didn’t investigate the cost deduction and ability of their proposed method to withstand failure tolerance.
Digital array radar’s task scheduling issue defines the optimal execution order for subject of the tasks to restrict the resources by using entropy dependent PSO methodology. This work [4] aims to achieve better performance in many phases. For the tough problem of N-P, an algorithm of hybridized PSO along with the optimization by integer programming models found to establish a structure for the full radar operation, which created a complete function of objectives. An enhanced PSO was introduced for comprehensively exploring the better performance schemes. The chaotic sequences were deployed to enhance the initialized solution quality. The entropy of Shannon was involved to show the population variation and then, tune the concerned variables.
Then, HPSO-Hybrid PSO [5] was a method for resolving the TAP - Task Assignment Problem. This method was associated with the issue of np-hard. PSO was a technologically advanced population dependent technique of heuristic optimization. The procedure had been established for dynamical scheduling of heterogeneous tasks and heterogeneous processors in a setup that were distributed. Balancing of load was an important problem in scheduling of task which was also considered in this work. This work of HPSO gave good performance than the Normal PSO to the issues pertaining to the assignment of task. The HPSO and PSO results were also correlated with some techniques of heuristic optimization namely Genetic Algorithm.
In general, Computing in Cloud environments were having huge heterogeneous self-operational systems collection along with an architecture of flexible computation. Task scheduling was a main step contributing to the cloud computing effectiveness. This scheduling was most important to enhance the service provider’s profit and consumption of low power, thereby minimizing the time taken for processing. [6, 7] made use of TSPSO – Task Scheduling using a multi objected nested PSO and orthogonal PSO for improvising processing time and energy optimization specifically. This proposed method outcomes were given rise by simulation with Cloudsim. In the environment of cloud computing, PSO was playing an crucial role in solving the issues of scheduling the task followed by optimizing the work flow pertaining to the system [8]. But, this adopted procedure falls easily into the local optimality for scheduling the scheme cost and time of execution rather than other methods. For addressing this difficulty and enhancing this method of computation, the methodology of traditional adaptive inertia weight particle group task scheduling was used by [8]. This method was able to equalize the particle search capacity among both the local and global levels to eliminate many local particles. This method gave rise to promising outcomes in terms of weight of inertia and state of the particle. Finally, this work was able to enhance the overall accuracy in convergence.
The cloud computing gave rise to many newer ways for application building, thereby giving many services to the users via the web virtualization. In cloud computing, task scheduling was the important element for using payable resources depending on the time. Thus, the load allocation was easily feasible among the resources of system by enhancing the usability and minimizing the executing time taken for executing the task. Hence, this research [9] made use of DAPSO – Dynamic Adaptive Particle Swarm Optimization for attaining the better performance and reducing the task set makespan along with the effective utilization of resources. This algorithm was a combination of CS and DAPSO methodologies known as MDAPSO methodology. Finally, they were able to observe that their hybridized methodologies surpassed the conventional PSO through the results.
As we already know, Cloud computing carried out client’s resource sharing and some services on-demand. For task scheduling, a new algorithm of hybridized GA-PSO methodology [10] was used. The goals of this methodology was also to provide minimum cost and then, balancing the load of designated task. Its performance was better than the methodologies of PSO, GA, WSGA-Work Scheduling with GA, HSGA-Hybrid heuristic scheduling with GA and MTCT. The proposed algorithm was quicker and much effective than the remainder algorithms.
Scheduling of appropriate resources to the workloads of cloud was a tough task, based on the requirements of Quality of Service in the applications of cloud. But still difficulties arising in dispersion, uncertainty and heterogeneity. So, [11] made a comprehensive preview of resource maintenance with scheduling of the task in the cloud environments. Their preview commented on how the researchers should choose appropriate methodologies for determining the workload schedule.
Since, the Cloud computing was the important method for enabling the connection capability of the VMs by TM-eFCFS – Task Migration based Scheduling methodology [12] using the enhanced-FCFS. This work make use of Non-live operation/task migration method for transmitting the tasks which were executed partially to another virtual machines for quick operations. The validation of this devised methodology was subjected to simulation using the cloudSim. Main factors like resource deployment and Makespan were investigated to validate the effectiveness of the TM-eFCFS.
A conventional yet and popular methodology of CMEFCFS – Cloudlet Migration based scheduling algorithm using Enhanced-First Come First Serve was used by [13]. This suggested work was subjected to simulation with the package of Cloudsim in order to validate its effectiveness. The validation was carried out to enhance parameters like execution time, completion time, and cost.
In distributed and parallel computing, task scheduling was an important task [14]. For the better task scheduling, UMR – Uniform Multi-Round was preferred to be used. Hence a novel methodology was suggested based on a modified form of UMR methodology, regarded as MSUMR – Master Service Uniform Multi-Round [14] was suggested. This algorithm increased the efficiencies of computing and scheduling irrespective of the bandwidth availability. Finally, on comparing with the existing works like UMR, extended multi-instalment and Multi-Instalment, this method outperformed by reducing the count of computer nodes that were unutilized.
[15] Divisible utilizations were used for the load partitioning which gave rise to few tiny fractions. This research contributes by portioning the whole divisible utilizations based on the load applications, available resources capacities and solutions. Its main objective was to reduce the time taken for the task completion by the intended application.
The dynamic nature of cloud computing provides ‘model of pay as per service pricing’ [16]. But cloud computing also had some problems like allocation of resources and scheduling the tasks to VMs. Thus, [16] founded the minimized time for completing the desired tasks with the aid of methodologies like BATS-Bandwidth Aware Divisible Scheduling, IDEA, ARIMA, and queuing vacation energy optimization. This research proved that the BATS would give rise to better completion time than the considered model of Berger source Data.
A novel meta-heuristic methodology comprising the integrated Genetic cum Firefly [17] was used to schedule the task in the cloud computing. It blends the mathematically formulated optimization by Firefly methodology along with the methodology of GA to contribute to the robust metaheuristic exploration. This methodology devised was analysed to cross verify its effectiveness against the existing methods of First In First Out and GA.
Cloud computing could process large amount of data by distributed services and its complex computational ability [18].This work [18] was objected to analyse many factors of PSO methodology in terms of its limitations, effectiveness and robustness. This work also made an investigation by examining the parameter suitability and cloud architecture virtualization in the platform with cloud computing as base.
A heuristic approach by [19] combined MAHP – Modified Analytic Hierarchy Process, LEPT – Longest Expected Processing Time pre-emption along with BATS. The resources were designated with the integration of BAR and BATS optimizing algorithms. The technique of dividing and conquering found to enhance the utilized IDEA – Improved Differential Evolutional Algorithm.
Cloud computing was the important technology in the services that were on demand [20]. The earlier method of scheduling tasks on the basis of requirements of resources for all the tasks processing without any reference to the storage, bandwidth, and memory. By introducing task scheduling method that primarily meets the requirements of users were able to yield better bandwidth, storage and memory within affordable costs.
TOPSIS – Technique of Order Precedence with Similarity to Ideal Solution [21] were majorly used for scheduling the task in the cloud environment. They divided this work into 2 phases where in TOPSIS was done in the initializing phase of task getting scheduled for concerned VMs and PSO was implemented in the next and final phase to schedule the predefined hierarchy. This integrated methodology of scheduling the tasks had better performance than the correlated existing methods such as ACO, multiple ACO and FUGE.
1.1 The major objective of this work is:
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To schedule the task efficiently
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To eliminate the faults in scheduling the tasks to the VMs.
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To reduce the overlapping of the tasks to the VM’s in the hosts and to balance the load, we can use MLRHE for the management of load.
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Finally, to validate the outcomes by comparing with the existing method