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Cloud Computing provides a promising platform for executing large scale workflow applications with enormous computational resources to offer on-demand services. Tasks in a workflow may need different type of computing resources such as storage, compute and memory type. However, inappropriate selection of these resources may lead to higher makespan and resource wastage. In this paper, we propose an effective two-phase algorithm for provisioning of cloud resources for workflow applications by using its structural features to minimize makespan and resource wastage. The proposed approach considers the nature of the tasks which may be compute intensive, memory intensive or storage intensive. We assume a realistic cloud model similar to Amazon EC2 that provides virtual machines for different types of workloads. Most importantly, the workflow model used in our approach is assumed to contain limited information about the task which is applicable for real situation. The performance of the proposed work is measured using five benchmark scientific workflows. The simulation results show that the proposed approach outperforms two existing algorithms for all these workflows. [ABSTRACT FROM AUTHOR]

Scheduling large workflows that are faced in many business as well as scientific domains such as economy, bioinformatics, astronomy and geophysics is an important area of research in the field of cloud computing. Many studies have been made to develop efficient algorithms for workflow scheduling that deal with multiple objectives. In the recent years, multi-criteria decision making (MCDM) methods have become popular for solving such multi-objective problems in various areas like risk management, climate change, renewable energy and so on. Particularly, the MCDM method called technique for order of preference by similarity to ideal solution (TOPSIS) has drawn extensive attention due to its easy understanding, fast and simple calculation. In this paper, we present a workflow scheduling algorithm in cloud environment based on TOPSIS that integrates entropy weight method (EWM). The proposed algorithm aims at minimizing makespan, cost, and energy consumption and maximizing the reliability. The algorithm is tested on various benchmark scientific workflows. The simulation results are compared with that of the related algorithms. The comparisons show that the proposed algorithm performs remarkably well in terms of cost and energy consumption while maintaining the other parameters within considerable limits. [ABSTRACT FROM AUTHOR]

Workflow scheduling is one of the burning topics that has drawn enormous attention recently in the research community of cloud computing due to its wide applications in astronomy, physics, bioinformatics, health care and so on. This is a well-known NP-complete problem. It presents an interesting aspect of achieving minimum processing time of all the tasks and maximum resource utilization in cloud resources. Therefore, many algorithms have been developed for workflow scheduling. However, most of them consider a static priority of the tasks which is non-realistic for heterogeneous cloud computing environment. In this paper, we propose a workflow scheduling algorithm which considers dynamic priority of the tasks. The algorithm undergoes a process of min-max normalization followed by the calculation of the dynamic threshold to dispatch the tasks into one of the virtual machines. The algorithm is extensively simulated using various benchmark, scientific and real-life workflows. All the simulated results are compared with other four existing workflow scheduling algorithms. The simulated results confirm that the proposed algorithm lags behind all the four existing algorithms in terms of makespan and average cloud resource utilization. The simulation results are also validated through analysis of variance statistical test. [ABSTRACT FROM AUTHOR]