Workflow scheduling algorithms in cloud environment: A review, taxonomy, and challenges

Cloud computing offers Information and Communication Technologies (ICT) user's new aspects of ease of services through the Internet. Cloud is a gradual evolution of distributed, cluster, grid and utility computing. Cloud environment attracts the myriads of service providers for development and deployment of their application because it provides ubiquitous and on-demand access to shared resources. The majority of cloud applications like scientific applications are represented as workflow. Workflow is related to the automation of a process that represented by task and data/control information is passed between dependent tasks based on defined set of principles, execution of these tasks require different resources with different Quality of Service parameters. Workflow scheduling is most important concerned in a cloud computing environment because it depends on optimization objectives (like makespan, cost, reliability, security, energy consumption and energy cost, load balancing etc.) of scientific applications. In this review paper, we describe various scientific applications, taxonomy and comprehensive survey of existing workflow scheduling algorithms. We also, classify these algorithms based on nature of the algorithm, optimization model used, optimization objectives and tool used.