Study of Service Models in Cloud Computing Manoj Kumar Dhruw

Transcription

1 International Journal of Researh (IJR) Available at Study of Servie Models in Cloud Computing Manoj Kumar Dhruw Student, Bahelor of Engineering in Computer Siene & Engineering Kirodimal Institute of Tehnology, Raigarh (C.G.), India Amarjit Ram Student, Bahelor of Engineering in Computer Siene & Engineering Kirodimal Institute of Tehnology, Raigarh (C.G.), India Rakesh Patel Leturer, Department of Information Tehnology Kirodimal Institute of Tehnology, Raigarh (C.G.), India Abstrat Cloud Computing is a tehnology whih is based on Network or Internet. We an aess the appliations as utilities over the internet through the loud omputing tehnology. Here in this paper we have disussed in three servie models in loud omputing. 1. What is loud? The term Cloud refers to a Network or Internet. In other words, we an say that Cloud is something, whih is present at remote loation. Cloud an provide servies over publi and private networks, i.e., WAN, LAN or VPN. Cloud omputing offers platform independeny, as the software is not required to be installed loally on the PC. Hene, the Cloud Computing is making our business appliations mobile and ollaborative. [1] 3. History of Cloud Computing: The onept of Cloud Computing ame into existene in the year 1950 with implementation of mainframe omputers, aessible via thin/stati lients. Sine then, loud omputing has been evolved from stati lients to dynami ones and from software to servies. The following diagram explains the evolution of loud omputing: [1] Appliations suh as , web onferening, ustomer relationship management (CRM) exeute on loud. [1] 2. What is loud omputing? Cloud Computing refers to manipulating, onfiguring, and aessing the hardware and software resoures remotely. It offers online data storage, infrastruture, and appliation. 4. Benefits: Fig. 2. History of Cloud Computing Cloud Computing has numerous advantages. Some of them are listed below Fig. 1. Cloud omputing One an aess appliations as utilities, over the Internet. Available online: P a g e 285

2 International Journal of Researh (IJR) Available at One an manipulate and onfigure the appliations online at any time. It does not require to install a software to aess or manipulate loud appliation. Cloud Computing offers online development and deployment tools, programming runtime environment through PaaS model. Cloud resoures are available over the network in a manner that provide platform independent aess to any type of lients. Cloud Computing offers on-demand selfservie. The resoures an be used without interation with loud servie provider. Cloud Computing is highly ost effetive beause it operates at high effiieny with optimum utilization. It just requires an Internet onnetion. Cloud Computing offers load balaning that makes it more reliable. [1] 5.1 INFRASTRUCTURE-AS A-SERVICE (IAAS): Infrastruture-as-a-Servie provides aess to fundamental resoures suh as physial mahines, virtual mahines, virtual storage, et. Apart from these resoures, the IaaS also offers: Virtual mahine disk storage Virtual loal area network (VLANs) Load balaners IP addresses Software bundles All of the above resoures are made available to end user via server virtualization. Moreover, these resoures are aessed by the ustomers as if they own them. [1] 5. Servie Models: Cloud omputing is based on servie models. These are ategorized into three basi servie models whih are Infrastruture-as a-servie (IaaS) Platform-as-a-Servie (PaaS) Software-as-a-Servie (SaaS) Benefits: IaaS allows the loud provider to freely loate the infrastruture over the Internet in a ost-effetive manner. Some of the key benefits of IaaS are listed below: Full ontrol of the omputing resoures through administrative aess to VMs. Flexible and effiient renting of omputer hardware. Portability, interoperability with legay appliations. [1] Available online: P a g e 286

3 International Journal of Researh (IJR) Available at Full ontrols over omputing resoure through administrative aess to virtual mahines: IaaS allows the ustomer to aess omputing resoures through administrative aess to virtual mahines in the following manner: Customer issues administrative ommand to loud provider to run the virtual mahine or to save data on loud server. Customer issues administrative ommand to virtual mahines they owned to start web server or to install new appliations. [1] Flexible and effiient renting of omputer hardware: IaaS resoures suh as virtual mahines, storage devies, bandwidth, IP addresses, monitoring servies, firewalls, et. are made available to the ustomers on rent. The payment is based upon the amount of time the ustomer retains a resoure. Also with administrative aess to virtual mahines, the ustomer an run any software, even a ustom operating system. [1] Portability, interoperability with legay appliations: It is possible to maintain legay between appliations and workloads between IaaS louds. For example, network appliations suh as web server or server that normally runs on ustomer-owned server hardware an also run from VMs in IaaS loud. [1] Charateristis: Here are the harateristis of IaaS servie model: Virtual mahines with pre-installed software. Virtual mahines with pre-installed operating systems suh as Windows, Linux, and Solaris. On-demand availability of resoures. Allows to store opies of partiular data at different loations. The omputing resoures an be easily saled up and down. [1] 5. 2 Platform as a Servie (PaaS): Platform as a Servie (PaaS) is a way to build appliations and have them hosted by the loud provider. It allows you to deploy appliations without having to spend the money to buy the servers on whih to house them. [2] Platform-as-a-Servie offers the runtime environment for appliations. It also offers development and deployment tools required to develop appliations. PaaS has a feature of pointandlik tools that enables non-developers to reate web appliations. [1] App Engine of Google and Fore.om are examples of PaaS offering vendors. Developer may log on to these websites and use the built-in API to reate web-based appliations. But the disadvantage of using PaaS is that, the developer loks-in with a partiular vendor. For example, an appliation written in Python against API of Google, and using App Engine of Google is likely to work only in that environment. The following diagram shows how PaaS offers an API and development tools to the developers and how it helps the end user to aess business appliations. [1] Benefits: Following are the benefits of PaaS model: Lower administrative overhead Customer need not bother about the administration beause it is the responsibility of loud provider. Available online: P a g e 287

4 International Journal of Researh (IJR) Available at Lower total ost of ownership Customer need not purhase expensive hardware, servers, power, and data storage. Salable solutions It is very easy to sale the resoures up or down automatially, based on their demand. More urrent system software It is the responsibility of the loud provider to maintain software versions and path installations. [1] Issues: Like SaaS, PaaS also plaes signifiant burdens on ustomer's browsers to maintain reliable and seure onnetions to the provider s systems. Therefore, PaaS shares many of the issues of SaaS. However, there are some speifi issues assoiated with PaaS as shown in the following diagram: [1] Sine PaaS appliations are dependent on network, they must expliitly use ryptography and manage seurity exposures. [1] Charateristis: Here are the harateristis of PaaS servie model: PaaS offers browser based development environment. It allows the developer to reate database and edit the appliation ode either via Appliation Programming Interfae or point-and-lik tools. PaaS provides built-in seurity, salability, and web servie interfaes. PaaS provides built-in tools for defining workflow, approval proesses, and business rules. It is easy to integrate PaaS with other appliations on the same platform. PaaS also provides web servies interfaes that allow us to onnet the appliations outside the platform. [1] 5.3 Software-as-a-Servie (SaaS): Lak of portability between PaaS louds: Although standard languages are used, yet the implementations of platform servies may vary. For example, file, queue, or hash table interfaes of one platform may differ from another, making it diffiult to transfer the workloads from one platform to another. [1] Event based proessor sheduling: The PaaS appliations are event-oriented whih poses resoure onstraints on appliations, i.e., they have to answer a request in a given interval of time. [1] Seurity engineering of PaaS appliations: The SaaS model provides software servies that are omplete appliations that are ready to use. The loud user simply onnets to the appliation, whih is running at a remote loation; the user might not know where. The loud servie provider is responsible for managing the loud infrastruture, the platform on whih the appliation is running, and the appliation itself. This approah eliminates the need for the users to install and run the appliation on their own omputers, thereby signifiantly reduing the need for maintenane and support. SaaS is sometimes referred to as appliations as a servie beause SaaS essentially provides appliations as a servie, rather than simply software in general. SaaS also inludes ontent servies (for example, video on demand) and higher value network servies (for example VoIP) as typially enountered in ommuniation servie provider senarios. Examples of ommerial implementations of SaaS environments inlude IBM Payment Systems, IBM Smart Cloud for Soial Business, PeopleSoft HR, Google Apps for Business. [3] There are several SaaS appliations listed below: Available online: P a g e 288

5 International Journal of Researh (IJR) Available at Billing and invoiing system Customer Relationship Management (CRM) appliations Help desk appliations Human Resoure (HR) solutions Some of the SaaS appliations are not ustomizable suh as Mirosoft Offie Suite. But SaaS provides us Appliation Programming Interfae (API), whih allows the developer to develop a ustomized appliation. [1] Benefits: Using SaaS has proved to be benefiial in terms of salability, effiieny and performane. Some of the benefits are listed below: Modest software tools Effiient use of software lienses Centralized management and data Platform responsibilities managed by provider Multitenant solutions. [1] Charateristis: Here are the harateristis of SaaS servie model: SaaS makes the software available over the Internet. The software appliations are maintained by the vendor. The liense to the software may be subsription based or usage based and it is billed on reurring basis. SaaS appliations are ost-effetive sine they do not require any maintenane at end user side. They are available on demand. They an be saled up or down on demand. They are automatially upgraded and updated. SaaS offers shared data model. Therefore, multiple users an share single instane of infrastruture. It is not required to hard ode the funtionality for individual users. All users run the same version of the software. [1] Modest Software Tools: The SaaS appliation deployment requires a little or no lient side software installation, whih results in the following benefits: No requirement for omplex software pakages at lient side. Little or no risk of onfiguration at lient side. Low distribution ost. [1] Issues: There are several issues assoiated with SaaS, some of them are listed below: Browser based risks: If the ustomer visits maliious website and browser s infeted, the subsequent aess to SaaS appliation might ompromise the ustomer's data. To avoid suh risks, the ustomer an use multiple browsers and dediate a speifi browser to aess SaaS appliations or an use virtual desktop while aessing the SaaS appliations. [1] Network dependene: The SaaS appliation an be delivered only when network is ontinuously available. Also network should be reliable but the network reliability annot be guaranteed either by loud provider or by the ustomer. [1] Lak of portability between SaaS louds: Transferring workloads from one SaaS loud to another is not so easy beause work flow, business logis, user interfaes, support sripts an be provider speifi. [1] Conlusion The study of servie models in loud omputing we an know that whih servie models provides whih kind of servies, benefits, harateristis, and limitation of servie models. We an also analyze whih kinds of seurity are neessary for servie models. Available online: P a g e 289

6 International Journal of Researh (IJR) Available at Referenes: [1] ng/loud_omputing_overview [2] Anthony T.Velte, Toby J.Velte, Robert Elsenpeter, Cloud Computing a Pratial Approah, TATA MGraw-Hill Edition [3] IBM Private, Publi, and Hybrid Cloud Storage Solutions by Larry Coyne, Shivaramakrishnan Gopalakrishnan, John Sing, seond edition (July 2014) Available online: P a g e 290