Introduction to cloud

Similar Systems and Concepts

• Cloud Computing is the result of the evolution and adoption of existing technologies and paradigms. The goal of cloud computing is to allow users to take benefit from all of these technologies, without the need for deep knowledge about or expertise with each one of them. The cloud aims to cut costs and help users focus on their core business instead of being impeded by IT obstacles.

• Similar technologies include:

• Virtualization - The main enabling technology for cloud computing. Virtualization abstracts the physical infrastructure, which is the most rigid component, and makes it available as a soft component that is easy to use and manage.

• Virtualization provides the agility required to speed up IT operations, and reduces costs by increasing infrastructure utilization • System Automation is the process which minimizes user involvement, speeds up the transaction processes, and reduces the possibility of human errors

Service-Oriented Architecture (SOA) - Method that help the user break problems into services that can be integrated to provide a solution. Cloud computing provides all of its resources as services and makes use of the well-established standards and best practices gained in the domain of SOA to allow global and easy access to cloud services in a standardized way.

• Utility Computing – This is a service provisioning model in which a service provider makes computing resources and infrastructure management available to the customer as needed, and charges them for specific usage rather than a flat rate.

• Grid Computing - a computer network in which each computer's resources (processing power, memory and data storage) are shared with every other computer in the system.

• Cloud computing has evolved from grid computing by addressing the QoS and reliability problems. • Cloud computing provides the tools and technologies to build data/compute-intensive parallel applications with much more affordable prices compared to traditional parallel techniques

Cloud Computing Characteristics

Cloud computing exhibits the following key characteristics:

a) Agility improves with users' ability to re-provision technological infrastructure resources.

b) API accessibility to software that enables machines to interact with cloud software in the same way that a traditional user interface (e.g., a computer desktop) facilitates interaction between humans and computers. Cloud computing systems typically use REST-based APIs (A REST- REpresentational State Transfer API is an application program interface that uses HTTP requests to GET, PUT, POST and DELETE data.)

c) Cost is claimed to be reduced, and in a public cloud delivery model capital expenditure is converted to operational expenditure.

d) Device and location independence- enable users to access systems using a web browser regardless of their location or what device they are using (e.g. PC, mobile phone). As infrastructure is off-site (provided by a third-party) and accessed via the Internet, users can connect from anywhere.

e) Virtualization technology- allows servers and storage devices to be shared and utilization be increased. Applications can be easily migrated from one physical server to another.

f) Multitenancy- enables sharing of resources and costs across a large pool of users thus allowing for:

❑ Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.)

❑ Peak-load capacity increases (users do not feel high load-levels)

❑Utilization and efficiency improvements for systems that are often only 10–20% utilized.

❑Reliability is improved if multiple redundant sites are used, which makes well-designed cloud computing suitable for business continuity and disaster recovery.

❑Scalability and elasticity via dynamic provisioning of resources on a self-service basis near real-time, without users having to feel peak loads.

❑Performance is monitored and consistent and loosely coupled architectures are constructed using web services as the system interface.

❑Security could improve due to centralization of data, increased security-focused resources

❑Maintenance of cloud computing applications is easier, because they do not need to be installed on each user's computer and can be accessed from different places

Cloud Computing Essential Characteristics

The National Institute of Standards and Technology's definition of cloud computing identifies five essential characteristics:

On-demand self-service

• On-demand self-service allows users to obtain, configure and deploy cloud services themselves using cloud service catalogues, without requiring the assistance of IT.

• Users are able to provision cloud computing resources without requiring human interaction, mostly done though a web-based self-service portal (management console).

Broad network access

• Cloud computing resources are accessible over the network, supporting an array of client platforms such as mobile devices and workstations (thin or thick client platforms, e.g., mobile phones, tablets, laptops, and workstations)

Resource pooling

• Service multiple customers from the same physical resources, by securely separating the resources on logical level.

Rapid elasticity

• Resources are provisioned and released on-demand and/or automated. This will make sure your application will have exactly the capacity it needs at any point of time.

Measured service

• Resource usage are monitored, measured, and reported (billed) transparently based on utilization. In short, pay for use