مقاله انگلیسی رایگان در مورد برنامه ریزی گردش کار در محاسبات ابری – الزویر 2016

Cloud computing is a technology that utilizes the internet and central remote servers to provide scalable services for its users (Kaur et al., 2011). It uses a great amount of heterogeneous distributed resources to deliver countless different services to its users with distinctive quality of service (QoS) requirements (Wu et al., 2013). Amazon EC2, GoGrid, Google App Engine, Microsoft Azure and Aneka are some of the prominent cloud computing platforms. Generally, clouds are classified as public clouds, private clouds, community clouds, hybrid clouds and cloud federation (Huang, 2014). A public cloud can be accessed by any subscriber (Huth and Cebula, 2011), but private clouds and their infrastructure are owned and accessed by some organizations (Huang, 2014). Also, community clouds are shared between several organizations and can be maintained by them or other service providers (Huang, 2014). Hybrid clouds deal with resources from both public and private clouds (Marcon et al., 2013). Also, due to the availability issue of the single clouds, a movement towards multi-clouds has emerged (AlZain et al., 2012) which focuses on the federation of different clouds (Jensen et al., 2011; Buyya et al., 2010). In addition, the services provided by cloud can be classified as software (SaaS), platform (PaaS), or infrastructure (IaaS) providers (Wang et al., 2014). SaaS provider leases enterprise software as a service to customers (Wu et al., 2011) and PaaS provider presents access to the required components over the internet to develop applications (Basishtha and Boruah). Also, IaaS clouds provide infrastructures resources such as processing, storage, networks, and soon (Dillon et al., 2010; Agarwal and Jain, 2014). Virtualization is one of the key enabling technologies of cloud computing which allows multiple Virtual Machines (VMs) to reside on a single physical machine (Pandey et al., 2010). A Virtual Machine (VM) emulates a particular computer system and executes the user issued tasks (Wang et al., 2010). By using the instantiation of the VMs, users can deploy their applications on resources with various performance and cost levels. In each physical machine or server, the VMs are managed by a software layer called hypervisor or the VM monitor which facilitates the VMs creation and isolated execution.