مقاله انگلیسی رایگان در مورد واسطه گری در محاسبات ابر محیطی مرتبط – الزویر 2018

Cloud computing provides computing platforms and facilitates to optimize utilization of infrastructure resources, reduces deployment time and increases flexibility. The popularity of cloud computing led to development of interconnected cloud computing environments(ICCE) such as hybrid cloud, inter-cloud, multicloud, and federated cloud, enabling the possibilities to share resources among individual clouds. However, individual proprietary technologies and access interfaces employed by cloud service providers made it difficult to share resources. Interoperability and portability are two of the major challenges to be addressee to ensure seamless access and sharing of resources and services. Many cloud service providers have similar service offerings but different access patterns. It is difficult and time consuming for a cloud user to select an appropriate cloud service as per the applications requirement. Cloud user has to gather information from various cloud service providers and analyze them. Cloud broker has been proposed to address the challenge of cloud users to get best out of cloud provider. Cloud broker is an entity which works as an independent third party between cloud users and cloud providers. Cloud broker negotiates with several cloud providers as per users requirements and tries to select the best services. Cloud broker coordinates the sharing of resources and provides interoperability and portability with other cloud providers. In this paper, a comprehensive survey of cloud brokering in interconnected cloud computing environments has been provided. The need and importance of cloud broker has been discussed. The existing architectures and frameworks of Cloud Brokering are reviewed. A comprehensive literature survey of various Cloud Brokering techniques is presented. A taxonomy of Cloud Brokering techniques has been presented and analyzed on the basis of their strengths and weaknesses/limitations. The taxonomy includes pricing, multi-criteria, quality of services, optimization and trust techniques. The techniques are analyzed on various performance metrics. Research challenges and open problems are identified from reviewed techniques. A model for cloud broker is proposed to address identified challenges. We hope that our work will enable researchers to launch and dive deep into Cloud Brokering challenges in interconnected cloud computing environments.

Introduction

Cloud Computing [1, 2, 3, 4] exploits Internet and Virtualization technologies in order to provide computing resources in virtualized from which are available on demand, reconfigurable, rapidly provisioned and ubiquitously accessible [5] through minimum or zero management efforts. Computing resources such as computer networks, applications & storage servers, various applications are delivered as different services such as Infrastructure as a Service(IaaS), Platform as a Service(PaaS), Software as a Service(SaaS). The on demand availability of computing resources empowers cloud users to avoid unnecessary infrastructure investment and subsequently up-gradation & maintenance cost. Service Oriented Architecture, Grid Computing [6], Cluster Computing [7] and Virtualization [8] technologies have preceded and enabled Cloud Computing. Container, a novel virtualization technique, provides improved utilization of cloud resources [9] by hiding low level hardware complexities. Docker packages applications and their dependencies in a single container [10]. Orchestration services are required to run multiple containers. Kubernetes [11], a container orchestrator, manages and deploys containers across cloud platforms and scales horizontally [9]. Cloud Computing can provide platform to run massively parallel applications using graphics processing unit(GPU) and tensor processing unit(TPU). It also provides storage as a service [12] using solid state drives(SSDs) for storing large databases. Various cloud providers such as Google, Azure and Amazon use TPUs, GPUs and SSDs for enhancing processing power for various applications such as machine learning. In spite of tremendous development of Cloud Computing, it still suffers from the lack of standardization [13]. In the lack of standards, every Cloud Service Provider(CSP) offers his services to Cloud Service Users (CSUs) through his own proprietary access interfaces and methods. Involvement of various technologies as listed above and different access patterns of cloud services have created a huge heterogeneous environment for Cloud Computing. Every CSU has to tailor his applications as per CSPs requirements in order to utilize their services. If a CSU later decides to change CSP then it has to again change his applications as per new CSP’s requirement. This becomes a time consuming and costly process which leads CSU to stuck with one CSP. It is called vendor lock-in [14] [15]. In order to provide computing facilities as utility, CSPs have to work in interconnect cloud computing environment (ICCE) [13]. Hybrid Cloud, InterCloud, Federated Cloud, and Multi Cloud are various Interconnected cloud computing environments. These interconnected cloud computing environments are considered as independent and different cloud environment.