International Journal of Electronics and Computer Science Engineering 1214 Available Online at www.ijecse.org ISSN- 2277-1956 Current Trends in Cloud Computing A Survey of Cloud Computing Systems Harjit Singh Assistant Professor: Department of Computer Science Punjabi University Akali Phoola Singh Neighbourhood Campus, Dehla Seehan (Sangrur), Punjab, India Email: hjit@live.com Abstract- Cloud computing that has become an increasingly important trend, is a virtualization technology that uses the internet and central remote servers to offer the sharing of resources that include infrastructures, software, applications and business processes to the market environment to fulfill the elastic demand. In today s competitive environment, the service vitality, elasticity, choices and flexibility offered by this scalable technology are too attractive that makes the cloud computing to increasingly becoming an integral part of the enterprise computing environment. This paper presents a survey of the current state of Cloud Computing. It includes a discussion of the evolution process of cloud computing, characteristics of Cloud, current technologies adopted in cloud computing, This paper also presents a comparative study of cloud computing platforms (Amazon, Google and Microsoft), and its challenges. Keywords Cloud computing, SAAS, PAAS, IAAS. I. INTRODUCTION A technology that has fastest growing segments in IT and shown its high growth rate in the last few years, is Cloud Computing. The technology uses the Internet and central remote servers to maintain data and applications. Cloud computing allows consumers and businesses to use applications without installation and access their personal files at any computer with internet access. This technology allows for much more efficient computing by centralizing storage, memory, processing and bandwidth. The technology is not revolutionary, but it is the outcome of the continuous advancement of the data management technology. The core idea of computing as a utility computing and grid computing developed in 1960 s. Around 1999, internet as the mechanism to provide Application as Service got developed. In 2005, the term cloud computing became popular and the sub classification of IaaS, PaaS & SaaS got formalized. The phrase Cloud originates from the cloud symbol used by flow charts and diagrams to symbolize the Internet. The term Cloud Computing refers to both the applications delivered as services over the Internet and the servers and system software in the data centers that provide those services. Cloud computing really is accessing resources and services needed to perform functions with dynamically changing needs. An application or service developer requests access from the cloud rather than a specific endpoint or named resource. What goes on in the cloud manages multiple infrastructures across multiple organizations and consists of one or more frameworks overlaid on top of the infrastructures tying them together. This paper describes the characteristics of cloud computing, cloud architecture, cloud deployment models, cloud service models and a comparative study of cloud computing systems. II. CLOUD COMPUTING CHARACTERISTICS A. On demand self services Computer services such as email, applications, network or server service can be provided without requiring human interaction with each service provider. Cloud service providers providing on demand self services include Amazon Web Services (AWS), Microsoft, Google, IBM and Salesforce.com. New York Times and NASDAQ are examples of companies using AWS. B. Resource Pooling The provider s computing resources are pooled together to serve multiple consumers using multiple-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. The resources include among others storage, processing, memory, network bandwidth, virtual machines and email services. The pooling together of the resource builds economies of scale.
Current Trends in Cloud Computing-A Survey of Cloud Computing Systems 1215 C. Rapid Elasticity Cloud services can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time. D. Mutitenacity It refers to the need for policy-driven enforcement, segmentation, isolation, governance, service levels, and chargeback/billing models for different consumer constituencies. Consumers might utilize a public cloud provider s service offerings or actually be from the same organization, such as different business units rather than distinct organizational entities, but would still share infrastructure. E. Measured Service Cloud computing resource usage can be measured, controlled, and reported providing transparency for both the provider and consumer of the utilized service. Cloud computing services use a metering capability which enables to control and optimize resource use. This implies that just like air time, electricity or municipality water IT services are charged per usage metrics pay per use. The more you utilize the higher the bill. Just as utility companies sell power to subscribers, and telephone companies sell voice and data services, IT services such as network security management, data center hosting or even departmental billing can now be easily delivered as a contractual service. III. CLOUD COMPUTING ARCHITECTURE Cloud computing Architectures are designs of software applications that use Internet accessible on-demand services (Figure 1). Applications built on Cloud Architectures are such that the underlying computing infrastructure is used only when it is needed, draw the necessary resources on- demand, perform a specific job, then relinquish the unneeded resources and often dispose themselves after the job is done. While in operation the application scales up or down elastically based on resource needs. Figure 1. Cloud Computing Architecture The rapid growth of cloud computing is largely based on the effective implementation of its architecture. In cloud computing, architecture is not just based on how the application will work with the intended users. Cloud computing requires an intricate interaction with the hardware which is very essential to ensure uptime of the application. Applications build on Cloud Architectures run in the cloud where the physical location of the infrastructure is determined by the provider. They take advantage of simple API s of Internet accessible services that scale ondemand, that are industrial strength, where the complex reliability and scalability logic of the underlying services remains implemented and hidden inside-the cloud. The usage of resources in Cloud Architecture is as needed, thereby providing the highest utilization with optimum cost. IV. CLOUD DEPLOYMENT MODELS A. Private Cloud The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise. B. Community Cloud The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise. Example: ebay.
IJECSE,Volume1,Number 3 Harjit Sing et al. C. Public Cloud Enterprises may use cloud functionality from others, respectively offer their own services to users outside of the company. Providing the user with the actual capability to exploit the cloud features for his / her own purposes also allows other enterprises to outsource their services to such cloud providers, thus reducing costs and effort to build up their own infrastructure. As noted in the context of cloud types, the scope of functionalities thereby may differ. Example: Amazon, Google Apps, Windows Azure. D. Hybrid Cloud A hybrid cloud is the private cloud which is linked to one or more public cloud services, which are centrally managed and provisioned as a unit. The hybrid cloud provides services as a mix of both public and private clouds as virtualized services. It is a cloud computing environment in which an organization provides and manages some resources in house and has others provided externally. This model is more prevalent for large enterprises which often already have substantial investments in the infrastructure required to provide resources in house. Hybrid Cloud provides applications and data in a secure manner so that many organizations prefer to keep sensitive data under their own control to ensure security. V. CLOUD SERVICE MODELS A. Software-as-a-Service This was the earliest cloud service and the first to enjoy widespread adoption. In a nutshell, SaaS is the online delivery of software functionality and capability without the need for locally running software. Rather, SaaS runs on a Web browser. Gmail and Salesforce are two popular SaaS products. Thousands of others exist delivering everything from graphics design to CRM to online security to basic word processing. Enterprise level SaaS providers deliver a wide variety of sophisticated applications such as product lifecycle management, supply chain management, and many other vertical applications. Direct benefits of SaaS include reduced hardware costs, reduced software licensing costs, and more flexible IT resources that can be dialed up or down quickly on demand. Secondary benefits include reduced or outsourced software support overhead and simpler licensing and product lifecycle management requirements. Equally important, SaaS applications allow users to access and manipulate their data anywhere they have a data connection from any device an important consideration in a world where nearly everyone has several compute platforms (mobile, laptop, tablet). Drawbacks include less ability to customize the application for specific business requirements, difficulty integrating SaaS with existing software based infrastructure, and budgeting uncertainties inherent in pay-as you-go pricing models. Increasingly, SaaS solutions are accepted by even the largest enterprises as viable replacements for traditional software which resides on an individual computer or is delivered over a local area network. B. Platform-as-a-Service Broadly speaking a Platform-as-a-Service (PaaS) is a cloud-based application development environment. Using a PaaS, companies can produce new applications more quickly and with a greater degree of flexibility than with older development platforms tied directly to hardware resources. Running application development on a PaaS has a number of key benefits. Programmers and development managers especially appreciate that the cloud provider handles all the care and maintenance of the underlying operating system(s), servers, storage, and application containers. PaaS environments can be extremely useful when development teams are widespread geographically or when partner companies or divisions share development efforts. Engineers can more easily share and back up a central repository of application data and implement tighter version control. Companies can build up and tear down PaaS environments on demand with no capital expenditures or long-term investment. Figure 2. Cloud Service Models
Current Trends in Cloud Computing-A Survey of Cloud Computing Systems 1217 A key drawback to many PaaS implementations, however, is the tie-in to one vendor s platform and infrastructure. Customers need to ensure that the platform allows for maximum portability of applications and data. Overall, companies can save considerable capital and operating expenses using a PaaS solution. However, companies running production applications in a PaaS environment need to perform detailed due diligence on the infrastructure underlying the PaaS itself. Many of PaaS platforms are built on top of other cloud platforms. If those underpinning infrastructure layers go offline or become unresponsive, then a PaaS might also become unavailable and with it the customer s production applications. This is precisely what happened when the popular and highly-regarded application development and runtime environment PaaS Heroku was taken down in April 2011 by a multi-day outage in Amazon Web Service s Elastic Compute Cloud. C. Infrastructure-as-a-Service The most foundational use of cloud computing is Infrastructure-as-a-Service (IaaS). This entails the rental of a complete computing resources for running applications, hosting data, or housing a company s entire computing environment. IaaS is the delivery model which provides computer Infrastructure as a service. It is a single tenant cloud computing layer where the dedicated resources of Cloud Computing vendors are shared only with the contract based clients at a pay-per-use fee. This greatly reduces the need for huge initial investments in computing hardware such as networking devices, computing servers, and processing unit. It is the base layer of the Cloud computing Virtualized stack. It serves as a base foundation for their execution, for the other two layers. Amazon EC2 is an example of an IaaS. The challenge with IaaS is that rack space and virtual server rentals reproduces and even magnifies many of the same IT management issues as outright server and network hardware ownership. Further downsides to IaaS include lack of control over your hardware and network infrastructure and exposure to unknown actors who may be running virtual machines on the same piece of hardware as your own organization s virtual machines. These other tenants in a multitenancy environment can suck up bandwidth, I/O and, in a worst-case scenario, present a significant security hazard by breaking out of their virtual machine to attack other tenants or the software kernel of the IaaS platform itself. VI. COMPARATIVE STUDY OF CLOUD COMPUTING SYSTEMS A comparative study of cloud computing systems is done which basically includes Amazon EC2, Google App Engine and Microsoft Azure based on the three parameters such as Technology benefits, business benefits and future trends (Figure 3). A. Amazon EC2 One or more instances of a virtual machine can be created for processing and for storage. Payment is made based on time the instances are running. Hourly charge vary from $0.020 (US East-Virginia) to $3.200 (South America-Sao Paulo) It is possible to have a reserve instance for an initial payment and discounted rate of usage. Data storage can be both relational and non-relational. Virtual machine can be of different capacity Standard(Small, Large, Extra Large), High- Memory(Double Extra Large, Quadruple Extra Large), High-CPU(Medium, Extra Large). Both Linux and Windows machine instances are supported. To persistent data storage, we can have one of the 3 alternatives Simple DB, Simple Storage Service (S3) or Relational Database Service (RDS). Simple DB and S3 storage mechanism is not RDBMS. RDS is an instance of MySQL so we can use it like a normal RDBMS. B. Google App Engine No need to instantiate any virtual machine. Application written in Python or Java can directly be deployed. We are charged on the actual normalized CPU cycles used. Storage is only non-relational. Charge is calculated on these parameters bandwidth, CPU, storage, emails send. Bandwidth usage charges are $0.12 per GB, CPU cycles usage charges are from $0.08 to $0.64 per hour depending upon the capacity, storage charges are $0.13 to $0.64 per GB per month. $0.0001 are charged per email. We have free quota for each of these parameters it may be enough for development, testing and small deployment. There are limits imposed for peak usage on many different parameters with daily limits & limits on usage in a burst. C. Microsoft Azure Offering has 3 main parts Windows Azure, SQL Azure and App Fabric. It uses Hyper-V for virtualization it works more like Amazon than like Google. There is an introductory offer where the service can be avail for free.
IJECSE,Volume1,Number 3 Harjit Sing et al. Payment is made for the resources used. One instance of Virtual Machine usage charges vary from $15.00 per month (Extra Small Instance) to $720.00 per month (Extra Large Instance). Data storage charges are $4.995 per month up to 100MB and $9.99 per month for greater than 100MB up to 1GB. Additional charges are applicable for additional usage more than 1GB. Bandwidth usage charges are $0.12 per GB for North America and Europe regions and $0.19 per GB for Asia Pacific Region. The development environment is Visual Studio through an SDK. VII. FINDINGS Amazon has been one of the first service providers that provide sharing of resources (storage space and computing) to create a very scalable and flexible platform and resizable compute capacity in the cloud. Amazon EC2 changes the economics of computing by allowing paying only for capacity that is actually used. The survey findings articulate that Amazon bested Google and Microsoft, and Amazon is recognized as the leader of the cloud computing, twice as many as Google and much more than Microsoft (Figure 3). Figure 3. Comparison of Cloud Systems VIII. CONCLUSION Cloud Computing provides computing services in today s competitive environment in a highly scalable way, the environments provided by the cloud strives to be reliable, customizable, dynamic, elastic and robust with a guaranteed Quality of Service. This proposed survey will provide an idea on the current trends in the cloud systems and comparison of Amazon EC2, Google App Engine and Microsoft Azure is made based on technology benefits, business benefits and future trends. In this paper the hype and challenges which are currently faced in the cloud computing industry are highlighted, and summarized the dominance of the Cloud Computing. REFERENCES [1] Michael Armbrust, Armando Fox, Rean Griffith, Anthony D. Joseph, Randy Katz, Above the Clouds: A Berkeley View of Cloud Computing, University of California Electrical Engineering & Computer Science, February 10th, 2009. [2] Boss G, Malladi P, Quan D, Legregni L, Hall H. Cloud omputing. IBM White Paper (2007). http://download.boulder.ibm.com/ibmdl/pub/software/dw/wes/hipods/cloud_computing_wp_final_8oct.pdf [3] Vouk, M.A. Cloud Computing - Issues, research and implementations, IEEE Information Technology Interfaces 30 th International Conference, page(s): 31~40 (2008). [4] Klems, M, Lenk, A, Nimis, J, Sandholm T and Tai S, What s Inside the Cloud? An Architectural Map of the Cloud Landscape, IEEE Xplore, pp 23-31, viewed 21 (2009). [5] L. Wang et al., Scientific Cloud 1. Computing: Early Definition and Experience, Proc. 10 th Int l Conf. High-Performance Computing and Communications (HPCC 08), IEEE CS Press, pp. 825-830 (2008). [6] CHEN Kang, ZHENG Wei-Min.,Cloud Computing: System Instances and Current Research. Journal of Software, 20(5): pp.1337 (2009). [7] D. Dikaiakos, D. Katsaros, P. Mehra, A. Vakali, Cloud Computing Distributed Internet Computing for IT and Scientific Research, IEEE Xplore, pp 23-31, viewed 22 (2009). [8] S. Singh, Different Cloud Com- 4. Putting Standards a Huge Challenge, The Economic Times, 4 June 2009; http://economictimes.india times.com/infotech/different -cloud-computing-standards/articleshow/ 4614446.cms. [9] Amazon. Amazon elastic compute cloud (Amazon EC2). (2009). http://aws.amazon.com/ec2/ [10] Jinesh Varia. Cloud architectures- Amazon web services [EB/OL]. ACM Monthly Tech Talk, http://acmbangalore.org/events/monthlytalk/ may-2008 cloudarchitectures amazon-web-services.html,(2008)
Current Trends in Cloud Computing-A Survey of Cloud Computing Systems 1219 [11] Udayan Banerjee, The Evolution of Cloud Computing, 8 March 2011, http://cloudcomputing.sys-con.com/node/1744132 Kevin Hartig, What is Cloud Computing?, 13 December 2009, http://cloudcomputing.sys-con.com/node/579826