Workflow Scheduling in Cloud Computing: A Survey

Workflow systems have become a major vehiclefor easy and efficient development of scientific applications. This type of systems can benefit from the resource provisioningtechnology offered by the cloud computing. In fact, the latteroffers on-demand virtualized resources to its users. These virtualresources can be added and released dynamically. Also, usersare charged on a pay-per-use basis. How to make appropriatedecisions when allocating resources to the tasks and dispatchingthe computing tasks to resource pool has become the main issuein cloud computing. The amount of allocated resources affects theexecution time of the applications and the cost incurred by the user. In fact, resource under-provisioning will necessarily affectthe performance. In contrast, over-provisioning can result in idleinstances and cause additional costs. Then, efficient scheduling algorithms are required for selection of best suitable resources for task execution. This paper focuses on some of the important workflow scheduling strategies. It brings out an exhaustive survey of such strategies in cloud computing and includes a detailed classification of them. Then, it presents a comparative analysis of the studied approaches. Finally, it stands out a critical challenge for further research.