2. Background of Cloud Computing
Content
Page 1
Chapter 2: Background of Cloud Computing
As the paradigm of cloud computing is relatively new, there are various open issues which need to be resolved before cloud computing is fully accepted by the broad community. Before proceeding to discussions on potential security issues of cloud computing and its future trend of development, a deeper explanation is needed of what cloud computing encompasses.
2.1 What is Cloud Computing? Cloud computing is commonly described as a range of services which are provided by an Internetbased cluster system. Such cluster system consist of a group of low-cost servers or Personal Computers (PCs), organizing the various resources of the computers according to a certain management strategy, and offering safe, reliable, fast, convenient and transparent services such as data storage, accessing and computing to clients. The NIST definition of cloud computing shall be used as our point of review on the background of cloud computing. To quote the definition: “Cloud computing is a model for enabling 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.” (NIST, 2009) The above definition is simply supported by FIVE key cloud characteristics, THREE delivery models and FOUR deployment models (NIST, 2009). These supporting properties are explained below, after which we will discuss various security issues and concerns related to cloud computing in the next chapter.
2.1.1
Key Characteristics of Cloud Computing
• On-demand self-service. Cloud computing resources can be procured and disposed of by the user without human interaction with each service provider. This automated process reduces the personnel overhead of the cloud provider, cutting costs and lowering the price at which the services can be offered. • Resource pooling. By using a technique called “virtualization”, the provider’s computing resources (e.g. storage, processing, memory, and network bandwidth) are pooled to serve multiple consumers using a multi-tenant model. This resource pool enables the sharing of virtual and physical resources by multiple consumers, “dynamically assigning and releasing resources according to consumer demand” (NIST 2009a). The consumer has no control or knowledge over the physical location of the resources being used, except when the consumer requests to limit the physical location of his data to meet legal requirements. • Broad network access. Cloud services are accessible over the network via standardized interfaces, enabling access to the service on heterogeneous client platforms such as mobile phones, tablets, laptops, and workstations. • Rapid elasticity. The available cloud computing resources are flexible and scalable to suit immediate business needs. By quickly increasing the cloud capabilities for a service if the demand rises; and quickly downsizing the capabilities when the demand drops. This automated process decreases the procurement time for new computing capabilities while preventing an abundance of unused computing power when the need has subsided.
Page 2 • Measured service. Cloud computing enables the measuring of used resources, as is the case in utility computing. The measurements can be used to provide information of resource efficiency to the cloud provider, and can be used to provide the consumer a payment model based on “pay-per-use.” For example, the consumer may be billed for the data transfer volumes or the volume of the data stored per month. 2.1.2 Cloud Delivery Models
The services offered by cloud computing vendors are available to customers on a pay-asyou-go basis, that is, services are provided on demand and customers are charged as these services are used. Also, users need not have prior knowledge about the administration of the resources involved and the physical infrastructures are not owned by customers, thus increasing the level of risk involved. These services are categorized into three main groups, namely Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). • Software as a Service (SaaS). This is a service delivery method in which the cloud vendors make software applications available to customers over a network, usually on a pay-as-you-go basis. These applications are accessed by users using a thin client via a web browser. SaaS is usually implemented to provide business software functionality to enterprise customers at a low cost. And at the same time allowing users to obtain the same benefits from commercially licensed, internally operated software without the associated complexity of installation, management, licensing, and steep up-front cost. (Kuyoro, Ibikunle, Awodele, 2011) The multi-tenant architecture of SaaS allows vendors to apply a single version of the application using a single hardware and network across a large pool of users thereby minimizing the cost. • Platform as a Service (PaaS). This service delivery method is one layer above IaaS. The cloud vendors provide developmental tools for building application to customers. It offers developers a complete software development life cycle management, from planning, designing, deployment, testing to maintenance without having to worry about maintenance issues of operating systems and server hardware. (Subashini, Kavitha, 2010) Clients using services offered on PaaS transfer even more costs from capital investment to operational expenses. However, one must acknowledge the fact that some constraints and possibly a certain degree of lock-in are posed by the additional functionality layers. • Infrastructure as a Service (IaaS). This is the foundation of all cloud services in which the cloud vendors provide the basic infrastructure that includes virtual platforms, raw storages, networking and so on. IaaS allows business organizations to focus more on areas of competence, which will in turn improve level of productivity. Since the burden of installation and management of infrastructure has been taken care of by cloud service providers, the hardware beneath could be completely abstracted and thereby allowing users to consume infrastructure as a service without the need to worry about the underlying management complexity.
2.1.3
Cloud Deployment Models
Page 3 Regardless of which delivery model is utilized, cloud offerings can be deployed in four primary ways, each with their own key features. The features of the deployment models are; (i) who owns the infrastructure; (ii) who manages the infrastructure; (iii) where is the
infrastructure located; (iv) and who accesses the cloud services.
FIGURE 1. CLOUD COMPUTING DEPLOYMENT ARCHITECTURE.
Image retrieved from http://blog.thehigheredcio.com/2011/02/22/cloud-deployment-models/ • Public clouds. Public cloud computing is based on massive scale offerings to the general public. The infrastructure is located on the premises of the provider, who also owns and manages the cloud infrastructure. Public cloud users are considered to be untrusted, which means they are not tied to the organization as employees and that the user has no contractual agreements with the provider. • Private clouds. Private clouds run in service of a single organization, where resources are not shared by other entities. “The physical infrastructure may be owned by and/or physically located in the organization’s datacenters (on-premise) or that of a designated service provider (off-premise) with an extension of management and security control planes controlled by the organization or designated service provider respectively“ (Bardin, Callas, Chaput et al. 2009). Private cloud users are considered as trusted by the organization, in which they are either employees, or have contractual agreements with the organization. • Community clouds. Community clouds run in service of a community of organizations, having the same deployment characteristics as private clouds. Community users are also considered as trusted by the organizations that are part of the community. • Hybrid clouds. Hybrid clouds are a combination of public, private, and community clouds. Hybrid clouds leverage the capabilities of each cloud deployment model. Each part of a hybrid cloud is connected to the other by a gateway, controlling the applications and data that flow from each part to the other. Where private and community clouds are managed, owned, and located on either organization or third party provider side per characteristic, hybrid clouds have these characteristics on both
Page 4 organization and third party provider side. The users of hybrid clouds can be considered as trusted and untrusted. Untrusted users are prevented to access the resources of the private and community parts of the hybrid cloud.
2.2
Importance of Cloud Computing
According to the top ten strategic technology trends for 2012 (Cooney, 2011) commissioned by Gartner, a famous global analytical and consulting firm, cloud computing emerged as first. This means that cloud computing will have an increased impact on most organizations in the future to come. Business leaders also suggested that cloud computing freed up IT staff time to innovate and gave IT staff a greater role in contributing to business strategy. With such significance perceived benefits, it’s important to consider the rewards of cloud computing in the modern technology era. The benefits of cloud computing include the following: • Reduced Cost. Opting for cloud computing is deemed to be more cost-effective over installing the same services in house. In-house servers are generally much more costly to maintain and come with high up-front costs. With the advent of cloud computing, IT solutions can now be outsourced and performed by external vendors that specialize in niche technologies allowing them to provide cheaper solutions to their clients. In other words, it means that these vendors have the resources, servers as well as the complete infrastructure in place that are needed to provide specialized service to a particular organization. This significantly cuts the cost of purchasing computing equipment and additionally frees up IT staff time and money from having to pay for in-house maintenance, repairs and troubleshooting. • Efficient performance and support One thing attractive about cloud computing to enterprises is the fact that all the software and applications available on cloud are updated automatically. With regards to performance, the cloud service allows employees to work from whatever locations as long as they have reliable Internet connection. Users can make use of cloud drives without having to transfer files from one to another. These cloud drives have built in security, a file directory system that people are familiar with navigating, the capability to upload files from a computer to the cloud drive, the capability to download files from the cloud drive to another computer, and share files with others. This allows people to become more productive by improving their access to information. The access to information is going to play a key role in the workforce's ability to telecommute remotely for organizations to save on facility costs. • Flexible development model Cloud-based application and storage enhance the flexibility and scalability of every enterprise. As there is no physical equipment to maintain, cloud computing can easily be customized to the needs of an organization, either to increase or scale down its capacity.
Page 5 This is particularly beneficial for companies that have heavy seasonal traffic, as well as those that expect very fast future growth. • Enhanced stability: Organizations need to protect their critical data to ensure that they can continue their daily operations to support their corporate missions. Most companies develop a disaster and recovery plan with a set of standard operating procedures (SOPs) put in place for imminent crisis. In the past without cloud technologies, companies usually have an alternative computing facility to save mission critical data at some remote location away from the corporate headquarters, in case of any crisis. Companies also routinely take full and incremental backups on a regular basis on physical storage devices. Now, companies can easily integrate cloud computing with their disaster recovery plan. Cloud vendors such as Google, Dropbox, actually provide the latest security protocols, continual data auditing, round-the-clock backup and networks that are stronger and more secure. Thus having a cloud storage solution helps to provide additional safeguard to ensure that corporate data is safe regardless of what happens to the in-house infrastructure.
Cloud computing is poised to continue its rapid pace growth. By reducing costs across the board, it enables businesses of all sizes to innovate and grow without requiring prohibitive amounts of upfront capital. Due to the extreme flexibility of cloud-based computing, many businesses are making the shift over to the cloud. There are very clear advantages in being able to reach core database information remotely, from any location, and by any authorized personnel. Business productivity can increase, along with the capacity for remote employment and easier data access. And not to mention cloud computing provides much more consistent uptime, as any issues are handled externally and proactively, as compared to in-house facility maintenance. Cloud computing will continue to stimulate new product and platform innovation. Cloud computing is positioned to be an important tool that companies can use to bundle with other services that can provide customers with new experiences. The number of possibilities that companies can combine with cloud computing is infinite. We are already seeing various innovations from companies such as Google, Dropbox and Microsoft. It is expected to see more synergies from different technologies and possibly more collaborations from cloud vendors in offering customers better solutions.
List of References:
1. M. Cooney. (2011, Oct) Gartner: The top 10 strategic technology trends for 2012. Retrieved from http://www.networkworld.com/news/2011/101811-gartner-technology-trends-252100.html 2. S.O. Kuyoro, F. Ibikunle, O. Awodele. “Cloud Computing Security Issues and Challenges”. International Journal of Computer Networks (IJCN), 3(5):2011 pp 247-255 3. S. Subashini, and V. Kavitha. (2010) “A survey on security issues in service delivery models of cloud computing.” J Network Comput Appl doi:10.1016/j.jnca.2010.07.006. Jul.,2010. 4. K. Hamlen, M. Kantarcioglu, L. Khan, B. Thuraisingham. “Security Issues for Cloud Computing” International Journal of Information Security and Privacy, 4(2), 39-51, April-June 2010 5. Dentel, D. (2013, July 15). Cloud computing benefits and importance on redesign your it infrastructure. Retrieved from http://cloudtweaks.com/2013/07/cloud-computing-benefits-andimportance-on-redesign-your-it-infrastructure/ 6. Smith, M. (2013, June 26). Importance and benefits of cloud computing in technology era. Retrieved from http://www.nittygrittycloud.com/blog/importance-and-benefits-of-cloudcomputing-in-technology-era/ 7. Singh, G. (2012). Why cloud computing is important. http://www.examiner.com/article/why-cloud-computing-is-important Retrieved from
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Chapter 2: Background of Cloud Computing
As the paradigm of cloud computing is relatively new, there are various open issues which need to be resolved before cloud computing is fully accepted by the broad community. Before proceeding to discussions on potential security issues of cloud computing and its future trend of development, a deeper explanation is needed of what cloud computing encompasses.
2.1 What is Cloud Computing? Cloud computing is commonly described as a range of services which are provided by an Internetbased cluster system. Such cluster system consist of a group of low-cost servers or Personal Computers (PCs), organizing the various resources of the computers according to a certain management strategy, and offering safe, reliable, fast, convenient and transparent services such as data storage, accessing and computing to clients. The NIST definition of cloud computing shall be used as our point of review on the background of cloud computing. To quote the definition: “Cloud computing is a model for enabling 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.” (NIST, 2009) The above definition is simply supported by FIVE key cloud characteristics, THREE delivery models and FOUR deployment models (NIST, 2009). These supporting properties are explained below, after which we will discuss various security issues and concerns related to cloud computing in the next chapter.
2.1.1
Key Characteristics of Cloud Computing
• On-demand self-service. Cloud computing resources can be procured and disposed of by the user without human interaction with each service provider. This automated process reduces the personnel overhead of the cloud provider, cutting costs and lowering the price at which the services can be offered. • Resource pooling. By using a technique called “virtualization”, the provider’s computing resources (e.g. storage, processing, memory, and network bandwidth) are pooled to serve multiple consumers using a multi-tenant model. This resource pool enables the sharing of virtual and physical resources by multiple consumers, “dynamically assigning and releasing resources according to consumer demand” (NIST 2009a). The consumer has no control or knowledge over the physical location of the resources being used, except when the consumer requests to limit the physical location of his data to meet legal requirements. • Broad network access. Cloud services are accessible over the network via standardized interfaces, enabling access to the service on heterogeneous client platforms such as mobile phones, tablets, laptops, and workstations. • Rapid elasticity. The available cloud computing resources are flexible and scalable to suit immediate business needs. By quickly increasing the cloud capabilities for a service if the demand rises; and quickly downsizing the capabilities when the demand drops. This automated process decreases the procurement time for new computing capabilities while preventing an abundance of unused computing power when the need has subsided.
Page 2 • Measured service. Cloud computing enables the measuring of used resources, as is the case in utility computing. The measurements can be used to provide information of resource efficiency to the cloud provider, and can be used to provide the consumer a payment model based on “pay-per-use.” For example, the consumer may be billed for the data transfer volumes or the volume of the data stored per month. 2.1.2 Cloud Delivery Models
The services offered by cloud computing vendors are available to customers on a pay-asyou-go basis, that is, services are provided on demand and customers are charged as these services are used. Also, users need not have prior knowledge about the administration of the resources involved and the physical infrastructures are not owned by customers, thus increasing the level of risk involved. These services are categorized into three main groups, namely Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). • Software as a Service (SaaS). This is a service delivery method in which the cloud vendors make software applications available to customers over a network, usually on a pay-as-you-go basis. These applications are accessed by users using a thin client via a web browser. SaaS is usually implemented to provide business software functionality to enterprise customers at a low cost. And at the same time allowing users to obtain the same benefits from commercially licensed, internally operated software without the associated complexity of installation, management, licensing, and steep up-front cost. (Kuyoro, Ibikunle, Awodele, 2011) The multi-tenant architecture of SaaS allows vendors to apply a single version of the application using a single hardware and network across a large pool of users thereby minimizing the cost. • Platform as a Service (PaaS). This service delivery method is one layer above IaaS. The cloud vendors provide developmental tools for building application to customers. It offers developers a complete software development life cycle management, from planning, designing, deployment, testing to maintenance without having to worry about maintenance issues of operating systems and server hardware. (Subashini, Kavitha, 2010) Clients using services offered on PaaS transfer even more costs from capital investment to operational expenses. However, one must acknowledge the fact that some constraints and possibly a certain degree of lock-in are posed by the additional functionality layers. • Infrastructure as a Service (IaaS). This is the foundation of all cloud services in which the cloud vendors provide the basic infrastructure that includes virtual platforms, raw storages, networking and so on. IaaS allows business organizations to focus more on areas of competence, which will in turn improve level of productivity. Since the burden of installation and management of infrastructure has been taken care of by cloud service providers, the hardware beneath could be completely abstracted and thereby allowing users to consume infrastructure as a service without the need to worry about the underlying management complexity.
2.1.3
Cloud Deployment Models
Page 3 Regardless of which delivery model is utilized, cloud offerings can be deployed in four primary ways, each with their own key features. The features of the deployment models are; (i) who owns the infrastructure; (ii) who manages the infrastructure; (iii) where is the
infrastructure located; (iv) and who accesses the cloud services.
FIGURE 1. CLOUD COMPUTING DEPLOYMENT ARCHITECTURE.
Image retrieved from http://blog.thehigheredcio.com/2011/02/22/cloud-deployment-models/ • Public clouds. Public cloud computing is based on massive scale offerings to the general public. The infrastructure is located on the premises of the provider, who also owns and manages the cloud infrastructure. Public cloud users are considered to be untrusted, which means they are not tied to the organization as employees and that the user has no contractual agreements with the provider. • Private clouds. Private clouds run in service of a single organization, where resources are not shared by other entities. “The physical infrastructure may be owned by and/or physically located in the organization’s datacenters (on-premise) or that of a designated service provider (off-premise) with an extension of management and security control planes controlled by the organization or designated service provider respectively“ (Bardin, Callas, Chaput et al. 2009). Private cloud users are considered as trusted by the organization, in which they are either employees, or have contractual agreements with the organization. • Community clouds. Community clouds run in service of a community of organizations, having the same deployment characteristics as private clouds. Community users are also considered as trusted by the organizations that are part of the community. • Hybrid clouds. Hybrid clouds are a combination of public, private, and community clouds. Hybrid clouds leverage the capabilities of each cloud deployment model. Each part of a hybrid cloud is connected to the other by a gateway, controlling the applications and data that flow from each part to the other. Where private and community clouds are managed, owned, and located on either organization or third party provider side per characteristic, hybrid clouds have these characteristics on both
Page 4 organization and third party provider side. The users of hybrid clouds can be considered as trusted and untrusted. Untrusted users are prevented to access the resources of the private and community parts of the hybrid cloud.
2.2
Importance of Cloud Computing
According to the top ten strategic technology trends for 2012 (Cooney, 2011) commissioned by Gartner, a famous global analytical and consulting firm, cloud computing emerged as first. This means that cloud computing will have an increased impact on most organizations in the future to come. Business leaders also suggested that cloud computing freed up IT staff time to innovate and gave IT staff a greater role in contributing to business strategy. With such significance perceived benefits, it’s important to consider the rewards of cloud computing in the modern technology era. The benefits of cloud computing include the following: • Reduced Cost. Opting for cloud computing is deemed to be more cost-effective over installing the same services in house. In-house servers are generally much more costly to maintain and come with high up-front costs. With the advent of cloud computing, IT solutions can now be outsourced and performed by external vendors that specialize in niche technologies allowing them to provide cheaper solutions to their clients. In other words, it means that these vendors have the resources, servers as well as the complete infrastructure in place that are needed to provide specialized service to a particular organization. This significantly cuts the cost of purchasing computing equipment and additionally frees up IT staff time and money from having to pay for in-house maintenance, repairs and troubleshooting. • Efficient performance and support One thing attractive about cloud computing to enterprises is the fact that all the software and applications available on cloud are updated automatically. With regards to performance, the cloud service allows employees to work from whatever locations as long as they have reliable Internet connection. Users can make use of cloud drives without having to transfer files from one to another. These cloud drives have built in security, a file directory system that people are familiar with navigating, the capability to upload files from a computer to the cloud drive, the capability to download files from the cloud drive to another computer, and share files with others. This allows people to become more productive by improving their access to information. The access to information is going to play a key role in the workforce's ability to telecommute remotely for organizations to save on facility costs. • Flexible development model Cloud-based application and storage enhance the flexibility and scalability of every enterprise. As there is no physical equipment to maintain, cloud computing can easily be customized to the needs of an organization, either to increase or scale down its capacity.
Page 5 This is particularly beneficial for companies that have heavy seasonal traffic, as well as those that expect very fast future growth. • Enhanced stability: Organizations need to protect their critical data to ensure that they can continue their daily operations to support their corporate missions. Most companies develop a disaster and recovery plan with a set of standard operating procedures (SOPs) put in place for imminent crisis. In the past without cloud technologies, companies usually have an alternative computing facility to save mission critical data at some remote location away from the corporate headquarters, in case of any crisis. Companies also routinely take full and incremental backups on a regular basis on physical storage devices. Now, companies can easily integrate cloud computing with their disaster recovery plan. Cloud vendors such as Google, Dropbox, actually provide the latest security protocols, continual data auditing, round-the-clock backup and networks that are stronger and more secure. Thus having a cloud storage solution helps to provide additional safeguard to ensure that corporate data is safe regardless of what happens to the in-house infrastructure.
Cloud computing is poised to continue its rapid pace growth. By reducing costs across the board, it enables businesses of all sizes to innovate and grow without requiring prohibitive amounts of upfront capital. Due to the extreme flexibility of cloud-based computing, many businesses are making the shift over to the cloud. There are very clear advantages in being able to reach core database information remotely, from any location, and by any authorized personnel. Business productivity can increase, along with the capacity for remote employment and easier data access. And not to mention cloud computing provides much more consistent uptime, as any issues are handled externally and proactively, as compared to in-house facility maintenance. Cloud computing will continue to stimulate new product and platform innovation. Cloud computing is positioned to be an important tool that companies can use to bundle with other services that can provide customers with new experiences. The number of possibilities that companies can combine with cloud computing is infinite. We are already seeing various innovations from companies such as Google, Dropbox and Microsoft. It is expected to see more synergies from different technologies and possibly more collaborations from cloud vendors in offering customers better solutions.
List of References:
1. M. Cooney. (2011, Oct) Gartner: The top 10 strategic technology trends for 2012. Retrieved from http://www.networkworld.com/news/2011/101811-gartner-technology-trends-252100.html 2. S.O. Kuyoro, F. Ibikunle, O. Awodele. “Cloud Computing Security Issues and Challenges”. International Journal of Computer Networks (IJCN), 3(5):2011 pp 247-255 3. S. Subashini, and V. Kavitha. (2010) “A survey on security issues in service delivery models of cloud computing.” J Network Comput Appl doi:10.1016/j.jnca.2010.07.006. Jul.,2010. 4. K. Hamlen, M. Kantarcioglu, L. Khan, B. Thuraisingham. “Security Issues for Cloud Computing” International Journal of Information Security and Privacy, 4(2), 39-51, April-June 2010 5. Dentel, D. (2013, July 15). Cloud computing benefits and importance on redesign your it infrastructure. Retrieved from http://cloudtweaks.com/2013/07/cloud-computing-benefits-andimportance-on-redesign-your-it-infrastructure/ 6. Smith, M. (2013, June 26). Importance and benefits of cloud computing in technology era. Retrieved from http://www.nittygrittycloud.com/blog/importance-and-benefits-of-cloudcomputing-in-technology-era/ 7. Singh, G. (2012). Why cloud computing is important. http://www.examiner.com/article/why-cloud-computing-is-important Retrieved from
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