Cloud computing and its transforming power

Transcription

1 Susana Sargento Instituto das Telecomunicações, Universidade de Aveiro. Cloud computing and its transforming power 153 The article describes the vision of cloud computing along with the stakeholders position in the ecosystem. Main features and business opportunities are presented, as well as remaining open-issues that need to be addressed, such as QoS, trust, security and privacy, and network interaction. Due to the specific nature of Clouds, additional aspects related to multi-tenancy and control over data location arise. Handling data in Clouds is still complicated, in particular, as data size and diversity grows, pure replication is no viable approach, leading to consistency and efficiency issues, as well as the lacking control over data location and missing provenance poses security and legal issues. Several of these issues still remain because no standards exist which obviously «blocks» interoperability. Aspects related to green IT also need to be evolved, as the Cloud can work in a green way by reducing unnecessary power consumption, if good scaling behavior and good economic models are employed. In a system where services quality is an essential requirement, an active network intervention is fundamental. The amount of applications ported to large Cloud platforms is increasing, including new applications such as online games and video processing. Cloud computing is changing the way IT services and network are provided, and more importantly, is changing the IT services and network themselves, with a complete restructuring on the business models to be provided. The plethora of new applications and challenges with the cloud environment will revolution the IT community.

2 154 Este artigo descreve a visão da computação em nuvem juntamente com a posição dos stakeholders no ecossistema. São apresentadas as principais caraterísticas e oportunidades de negócio, bem como todas as questões remanescentes que precisam de ser resolvidas, como a de qualidade de serviço, a confiança, a segurança e a privacidade, e a interação da rede. Devido à natureza específica das Nuvens, surgem aspetos adicionais relacionados com a multiguarda e o controlo sobre a localização dos dados. Lidar com dados em Nuvem continua a ser complicado, em especial dado que o tamanho e diversidade dos dados vai crescendo e a replicação pura não é uma abordagem viável, levando a questões de consistência e de eficiência; além disso, a falta de controlo sobre a localização dos dados e a ausência de uma proveniência colocam questões legais e de segurança. Várias destas questões mantêm-se porque não existem padrões que «bloqueiem» de forma óbvia a interoperabilidade. Aspetos ligados às IT verdes também precisam de ser desenvolvidos, uma vez que a Nuvem pode funcionar de forma verde reduzindo consumos desnecessários de energia, desde que sejam usados bons modelos económicos e comportamento de escala. Num sistema em que a qualidade dos serviços é uma exigência essencial, uma intervenção ativa na rede é uma exigência fundamental. A quantidade de aplicações portadas para grandes plataformas de Nuvem está a aumentar, incluindo novas aplicações como jogos online e processamento de vídeo. A computação em nuvem está a mudar a forma como os serviços e redes de TI são fornecidos e, mais importante ainda, traz uma completa reestruturação dos modelos de negócio a serem proporcionados. A miríade de novas aplicações e de desafios no ambiente de nuvem revolucionará a comunidade das TI.

3 Cloud computing overview Today, Internet clients are used to run applications and query data that are stored in their personal devices. A main advantage of this model lies on the fact of being possible, at least most of the times, to use applications and have access to data without being connected to a company network, university network, or generically, to the Internet. However, this offline access is limited to the sharing of information, access to new applications, services and content, and presents high costs in licenses of software and infrastructure with capacity to run and host the applications, services or content. The constant evolution of access technologies, whether wired, fiber optics, or wireless is making the access to Internet ubiquitous, faster and with higher quality. The proliferation of Internet access allows users to have the possibility to use services available directly through it, which translates in a change of the paradigm of using applications and in the way of communicating, Figure 1 The evolution of Cloud computing popularizing in this way the so-called Cloud Computing (CC) paradigm. The concept of CC has no standard or official definition. Several definitions can be found in the literature, being the National Institute of Standards and Technology s (NIST) definition the most mentioned one: «Cloud computing is a pay-per-use model for enabling available, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, services) that can be rapidly provisioned and released with minimal management effort or service provider interaction». Even without definition, there is a common understanding: CC is not a revolutionary concept but rather an evolutionary one, as it has grown from concepts and frameworks such as Grid Computing, Utility Computing and Software-asa-Service (SaaS) Figure 1. In this sense, CC cannot be seen as a technology but instead as a combination of technologies as it pulls together Grid Computing resource s sharing functionality, with Utility Computing s business model, along with the SaaS s subscription for services on-demand. 155 Cloud Computing s evolution Grid Computing Utility Computing Software - as-a-service Cloud Computing Solving large problems with parallel computing Offering computing as a metered service On-demand service subscription On-demand services using a pay-as-you-go model CC takes computational resources and applications to a level where they can be provisioned as a service, just like water and electricity. In a CC environment applications and data do not need to be necessarily installed or stored in the user s device, being available by the Cloud through dedicated service providers, also referred to as Cloud Providers (CP). The CP is responsible, for example, for guaranteeing the storage, maintenance and backup of the user s data, while the user limits itself to access the platform provided and paying only for what he needs a pay-asyou-go model. Technically, the term «Cloud» refers to a computational infrastructure or platform, capable of scaling dynamically according to the user s need, resilient, providing ubiquity and guarantees of on-demand delivery of the services to the user through the Internet. Clouds are of particular commercial interest not only with the growing

4 156 trend to outsource IT so as to reduce management overhead and to extend current, limited IT infrastructures «The global market for Cloud Computing technologies is going to grow by a robust Compound Annual Growth Rate (CAGR) of 23.4% over the next five years, with an aggregate of over $300 Billion over that period» as Figure 2 shows. CC reduces the entrance barrier (minimum infrastructure entry cost) and risks (reduced risk of wasting resources) for new service providers to launch their solutions. Costs for business customers are shifted from CAPital EXpenditure (CAPEX) to OPerational EXpenditure (OPEX). Its provisioning environment stands out from classical ones by its high scalability. However, there are concerns, especially regarding security if a business places its valuable knowledge, information and data on an external service. Most important IT players and beyond (network operators, device manufactures), such as Sun, Oracle, Google, EBay, and Microsoft, provide today various types of CC commercial platforms. E.g.: Google Docs and Microsoft Office 365 give users the ability to use traditional Office tools (e.g.: Word, Excel, Power- Point, and OneNote) through a browser with no need to have any additional program installed in the device. Figure 2 Cloud computing cumulative market 2010/2016 Allowing all relevant features in a Cloud-based architecture requires real-time access to the Internet, which is becoming increasingly available through broadband access, not only in the wired domain (e.g. fiber) but also in the wireless domain (e.g. WiMAX, Wi-Fi and LTE). CC s main features include: Unlimited computing capacity (theoretically; it gives the user the illusion of unlimited); Offloads a great amount of computing and storage from user devices; «Disconnects» the services from the user devices (device independency); On-demand self-service; Pay per use business model. In a user s perspective, by not storing user or service data on the device (there are of course exceptions, e.g. service address and access credentials), the user relates to the service that it affords rather than to the device. Mobile Cloud computing Mobile Cloud computing (MCC) comes from the «adaptation» of Cloud computing to the mobile environment. MCC refers to «anywhere anytime secure access to data and services». Mobile refers to smartphones, e-book readers, netbooks, in-car entertainment systems, navigation systems and similar devices. The limited processing power and storage capabilities of these devices are a stimulus for moving the core services of the devices «into the Cloud», where services are made available to the user through browser-based user interfaces and deploying local capabilities of the devices. The strong adoption of intelligent mobile devices will continue to drive users to Cloud-based services and applications. A key feature of MCC is its capability to enable and enrich software services by taking advantage of available information and intelligence from mobile networks and systems. MCC is forecasted to have great impact on the provisioning of mobile services, leading to new opportunities for its stakeholders, including Mobile Network Operators (MNOs). The Internet s core network has the means (bandwidth, robust security mechanisms and quality) to administer the demands of most CC services; however, MCC demands particular requirements that go beyond fixed-line CC service delivery, mainly due to significant mobile access bandwidth limitations. In this sense, MNOs will naturally have a fundamental role in deploying and provisioning an efficient MCC environment.

5 At the same time, it is obvious that MCC is not going to be the best solution for every need. It poses challenges due to the intrinsic nature and constraints of wireless networks and devices. This is especially true when it comes to richinternet and immersive mobile applications, e.g. online gaming and augmented reality that require high-processing capacity and minimum network latency. These will most probably continue to be partially processed locally on powerful smartphones and mobile tablets. Mobile broadband networks generally require longer execution times for a given application to run in the Cloud, and network latency issues may deem certain applications and services unfit for the mobile Cloud. As an example, it is a belief that CC will become a disruptive force in the mobile world not only due to the number of users the technology has the power to reach, but also due to how it will change the applications distribution. Today s mobile applications are tied to the device s market e.g. to have an Apple application the user needs to have an Apple device such as an iphone or ipad (the same happens with Blackberry applications and others). Android is the exception to this rule, and that is probably the main reason why it is gaining market in such a short period of time. MCC breaks this relationship, since, as CC, the only requirement to a mobile application is the access to the web. With the huge market supply and constant evolution of devices (e.g.: laptops, smartphones and tablets), users are constantly switching devices. This can turn out to be quite a headache for users: to change data from one device to another, reconfigure settings; incompatibility issues between devices and applications/services. With MCC, the user can switch devices without witnessing data loss and can also have multiple devices (at home and at work; in a laptop and a smartphone) able to support the same service without synchronization problems. In this way, the service is no longer tied to the device but to the user device independency. Cloud computing and networks As previously referred, the range of Cloud services can go from a simple storage or computing service to a video on-demand or gaming service. Such diversity brings with it requirements at two different levels: at the Cloud level, where computational resources must be able to guarantee the demand of such services; and at the access level, i.e., depending on the service being consumed different quality levels to the services are required in the network. The Cloud is known by its scalability and elasticity, which may suggest variation in the network requirements as the Cloud scales up or down. Moreover, the Cloud allows this to be done on-demand. However, the Cloud and network are two different entities, i.e., a user may request a Cloud service which inherently has certain access requirements that are not provisioned by the network. In some cases, when the typical best effort Internet model is not enough, it can be done the purchase of a network service that meets the Cloud service requirements, connecting the user and the Cloud hosting the service. Obviously, the network service is static and cannot follow the dynamicity of the Cloud (increase or decrease of quality requirements). Furthermore, the Cloud assumes the concept of «anywhere, anytime access», and even with static network service the user faces the drawback of mobility. Network services are not mobile, and thus, cannot follow the user. This is a major drawback which certainly will disrupt the leverage of Cloud services, mainly as more «heavy» services are not able to be attended in a best-effort way appear. CC today relies on the power of big data centers, which can in the future become a concern. Even though it was possible to provide network services able to connect the users and the Cloud effectively, at a certain point the network itself would not stand due to the centralized nature of today s data centers. In order to address the current limitations of CC related to the network, a new concept arouse, the concept of Cloud Networking (CN). Similar to CC, CN has no standard definition, but we can say that it goes beyond classical networks to redefine scalability, administration and management processes. Some key considerations of CN encompass scalability, guaranteed performance, self-healing and extensible management. We consider CN not only as the combination of network services with today s Cloud (big data centers), but also as an evolution of the Cloud, where its con- 157

6 158 cept is extended to smaller Cloud data center s (which we call Cloud sites) distributed through the network, in strategic places, where some are located in network edges closer to users. With a distributed Cloud it is possible to move content between sites with the purpose of providing the user with better Quality of Experience (QoE), while at the same time optimizing the occupancy of the network infrastructure. In order to clarify what we mean, we now provide a small example: imagine a user consuming a Cloud service from a data center located in the core of the network; suppose that the user has a network service able to provide the required quality for the service; at a certain point in time several users in the same geographical area also start consuming the service; this will increase the demand on the network. At this point, with a Cloud site nearer the geographical area of the users, it may be beneficial to move the service closer to the user along with the associated network service, thus optimizing the whole service. With this approach, it will be possible to manage demand for network resources instantaneously, to meet the changing service needs, enabling fast and efficient responses in a dynamic environment. can work in a green way by reducing unnecessary power consumption, if good scaling behavior and good economic models are employed. With computing centers among the biggest energy consumer, reducing energy consumption will significantly reduce ownership costs. Therefore, in such an environment autonomy becomes a key feature for the Cloud architecture. It has also been made clear that, in a system where services quality is an essential requirement, an active network intervention is fundamental. The amount of applications ported to large Cloud platforms is increasing, including new applications such as online games and video processing. These highly distributed applications raise new challenges. Being able to adjust rapidly and without human intervention to changes in the environment is highly important. It is clear that cloud computing is changing the way IT services and network are provided, and more importantly, is changing the IT services and network themselves, with a complete restructuring on the business models to be provided. The plethora of new applications and challenges with the cloud environment will revolution the IT community. Summary and conclusion This section described the vision of cloud computing along with the stakeholders position in the ecosystem. Main features and business opportunities were presented, as well as remaining openissues that need to be addressed, such as QoS, trust, security and privacy, and network interaction. These aspects have always posed issues in any internet provision service, but due to the specific nature of Clouds, additional aspects related to multi-tenancy and control over data location arise. Handling data in Clouds is still complicated in particular, as data size and diversity grows, pure replication is no viable approach, leading to consistency and efficiency issues. Also, the lacking control over data location and missing provenance poses security and legal issues. Several of these issues still remain because no standards exist which obviously «blocks» interoperability. Aspects related to green IT also need to be evolved, as the Cloud References [1] NIST Working Definition of Cloud Computing, Google groups, May Retrieved, January 2011, from: group/cloudforum/web/nist-working-definition-of-cloud-computing?pli=1. [2] P. Neves, J. Soares, et al. «Cloud Computing: Principais Conceitos e Tendências», Portugal Telecom Inovação, December [3] M. Armbrust, I. Stoica, M. Zaharia, et al. «A view of Cloud computing», Communications of the ACM, vol. 53, [4] J. Mathews, «The Future of Virtualization, Cloud Computing and Green IT Global Technologies & Markets Outlook ». Market Intel Group LLC, October [5] M.A. Vouk, «Cloud computing; Issues, research and implementations», ITI th International Conference on Information Technology Interfaces, Cavtat/Dubrovnik, Croatia, 2008.

7 [6] The Future of Cloud Computing: Opportunities for European Cloud Computing Beyond 2010, Expert Group Report, European Commission Information Society and Media. [7] Google Docs, [8] Microsoft office 365, [9] Opportunities and Challenges for Operator in the Mobile Cloud. D1: Mobile Cloud Technologies and Trends. Eurescom Study Report, October [10] Dusan Belic, ABI Research: One billion people will use mobile Cloud services by Intomobile, September Retrieved, November 2010, from: com/2009/09/09/abi-research-one-billion-people-will-use-mobile-cloud-services-by-2014/. [11] Jayshree Ullal, What is Cloud Networking? October Retrieved, January 2011, from: com/2008/10/10/jayshree-ullal-what-is-cloudnetworking-.aspx. 159