Cloud computing

Information systems enable the transmission of information within and beyond the organisation. These systems rely on networks to transmit information between devices. Network architectures and infrastructures should, therefore, be designed to make this operational.

Architecture: layout or blueprint for how devices are supposed to work together.

Infrastructure: actual hardware [Ethernet cables, routers], software, and networking components [switches, bridges] that support the processing and transfer of information.

One of the most popular architectures is Cloud computing.

Cloud computing

Computing is being transformed into a model consisting of services that are commoditized and delivered in a manner similar to utilities such as water, electricity, gas, and telephony. In such a model, users access services based on their requirements regardless of where the services are hosted. Several computing paradigms, such as grid computing, have promised to deliver this utility computing vision. Cloud computing is the most recent emerging paradigm promising to turn the vision of ‘computing utilities’ into a reality

The term 'cloud' appears to have its origins in network diagrams that represented the internet, or various parts of it, as schematic clouds. Hence 'Cloud computing' was coined for what happens when applications and services are accessed through the internet 'cloud.' The internet plays a fundamental role in cloud computing since it represents either the medium or the platform through which many cloud computing services are delivered and made accessible. Note: Medium refers to IT Infrastructure (networks) that should be in place to ensure services are delivered. 

Hence, cloud computing can best be described as a model for enabling ubiquitous, convenient, on-demand network access to a pool of configurable computing resources (e.g networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. As you can see from the components of IS in week 1, the cloud computing models require all IS components in order to be functional.

Characteristics

Shared Infrastructure — Uses a virtualized software model, enabling the sharing of physical services, storage, and networking capabilities. The cloud infrastructure, regardless of the deployment model, seeks to make the most of the available infrastructure across several users.

Dynamic Provisioning — Allows for the provision of services based on current demand requirements. This is done automatically using software automation, enabling the expansion and contraction of service capability, as needed. This dynamic scaling needs to be done while maintaining high levels of reliability and security.

Network Access — Needs to be accessed across the internet from a broad range of devices such as PCs, laptops, and mobile devices, using standards-based APIs (for example, ones based on HTTP). Deployments of services in the cloud include everything from using business applications to the latest application on the newest smartphones.

Managed Metering — Uses metering for managing and optimizing the service and to provide reporting and billing information. In this way, consumers are billed for services according to how much they have used during the billing period.

In short, cloud computing allows for the sharing and scalable deployment of services, as needed, from almost any location, and for which the customer can be billed based on actual usage. Below is an additional video, from BlackBoard, describing characteristics of Cloud Computing.

Service models

Once a cloud is established, how its cloud computing services are deployed in terms of business models can differ depending on requirements. The primary service models being offered are commonly known as:

Software as a Service (SaaS): Software as a service is a method for delivering software applications over the Internet, on demand and typically on a subscription basis. With SaaS, cloud providers host and manage the software application and underlying infrastructure and handle any maintenance, like software upgrades and security patching. Users connect to the application over the Internet, usually with a web browser on their phone, tablet or PC. Companies such as Microsoft have made a significant investment in this area. As part of the cloud computing option for Microsoft® Office 365 (this is a service provided to UCT students – see details on ICTS website), its Office suite is available as a subscription through its cloud-based Online Services.

Platform as a Service (PaaS): Platform as a service refers to cloud computing services that supply an on-demand environment for developing, testing, delivering and managing software applications. PaaS is designed to make it easier for developers to quickly create web or mobile apps, without worrying about setting up or managing the underlying infrastructure of servers, storage, network and databases needed for development. Examples include Amazon Web Services (AWS), Rackspace and Microsoft Azure. UCT's ICTS offers some cloud services  for students to use when working on projects that require them to build and deploy web and/or mobile applications.

Infrastructure as a Service (IaaS): The most basic category of cloud computing services. With IaaS, you rent IT infrastructure—servers and virtual machines (VMs), storage, networks, operating systems—from a cloud provider on a pay-as-you-go basis. Examples of service providers in this space include IBM, Amazon EC2 and Rackspace. This option is preferred  by organisations that want full control of their infrastructure and IT services.

Deployment models

Deploying cloud computing can differ depending on requirements, and the following three deployment models have been identified, each with specific characteristics that support the needs of the services and users of the clouds in particular ways.

Private Cloud — The cloud infrastructure has been deployed, and is maintained and operated for a specific organization. A private cloud can be physically located on the company’s on-site datacenter. Some companies also pay third-party service providers to host their private cloud. A private cloud is one in which the services and infrastructure are maintained on a private network.

Public Cloud — Public clouds are owned and operated by a third-party cloud service providers, which deliver their computing resources like servers and storage over the Internet. Microsoft Azure is an example of a public cloud. With a public cloud, all hardware, software and other supporting infrastructure are owned and managed by the cloud provider. You access these services and manage your account using a web browser. This enables a consumer to develop and deploy a service in the cloud with very little financial outlay compared to the capital expenditure requirements normally associated with other deployment options.

Hybrid Cloud — Hybrid clouds combine public and private clouds, bound together by technology that allows data and applications to be shared between them. By allowing data and applications to move between private and public clouds, a hybrid cloud gives your business greater flexibility, more deployment options and helps optimize your existing infrastructure, security and compliance.

Advantages

Cost Savings — Organisations can reduce their capital expenditures and use operational expenditures for increasing their computing capabilities. This is a lower barrier to entry and also requires fewer in-house IT resources to provide system support.

Scalability/Flexibility — Organisations can start with a small deployment and grow to a large deployment fairly rapidly, and then scale back if necessary. Also, the flexibility of cloud computing allows companies to use extra resources at peak times, enabling them to satisfy consumer demands.

Reliability — Services using multiple redundant sites can support business continuity and disaster recovery.

Maintenance — Cloud service providers do the system maintenance, and access is often through the web which does not require application installations onto PCs, thus further reducing maintenance requirements.

Accessibility — Mobile workers have increased productivity due to systems accessible in infrastructure available from anywhere (internet)

Disadvantages

The following are some of the notable challenges associated with cloud computing. Its important to note that the extent of these challenges of depends on the specific service as well as deployment model being utilized.

Security and Privacy — Perhaps two of the more “hot button” issues surrounding cloud computing relate to storing and securing data, and monitoring the use of the cloud by the service providers. These issues are generally attributed to slowing the deployment of cloud services. These challenges can be addressed, for example, by storing the information internal to the organization but allowing it to be used in the cloud. For this to occur, though, the security mechanisms between the organization and the cloud need to be robust and a Hybrid cloud could support such a deployment.

Lack of Standards — Clouds have documented interfaces; however, no standards are associated with these, and thus it is unlikely that most clouds will be interoperable. The Open Grid Forum is developing an Open Cloud Computing Interface to resolve this issue and the Open Cloud Consortium is working on cloud computing standards and practices. The findings of these groups will need to mature, but it is not known whether they will address the needs of the people deploying the services and the specific interfaces these services need. However, keeping up to date on the latest standards as they evolve will allow them to be leveraged, if applicable.

Reliance on Third Parties — Using cloud computing services especially for core operations exposes your organisation to risks associated with the service providers. Business events such as service provider going out of business or being bought by another company can greatly impact their ability to offer their services to your organisation.

Compliance Concerns — Different legislation about data privacy in different countries tend to create disputes as to the rights that third parties (including government agencies) have to your data. The Protection of Personal Information (POPI) Act in South Africa, the Sarbanes-Oxley Act (SOX) in the US and Data Protection directives in the EU are just some of the many compliance issues affecting cloud computing, based on the type of data and application for which the cloud is being used.  As with security and privacy mentioned previously, these typically result in Hybrid cloud deployment with one cloud storing the data internal to the organization.