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CLOUD COMPUTING. Cloud Computing - “ programska rješenja u oblacima ”. One of the more significant endorsements ( support ) of “the cloud” took place when Apple unveiled its iCloud service.
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Cloud Computing - “programska rješenja u oblacima” • One of the more significant endorsements (support) of “the cloud” took place when Apple unveiled its iCloud service. • Apple founder Steve Jobs stated at the launch that iCloud would replace the PC for many people who use the PC to store media and data.
The name cloud computing was inspired by the cloud symbol that is often used to represent the Internet in flowcharts and diagrams.
Cloud computing is a model for enabling on-demand access to shared pool of compute resources e.g. server, application & service. • In other words, cloud computing is a model for delivering IT services. Instead of a direct connection to the server, the resources are retrieved from the Internet though web-based tools and applications. • These services are broadly divided into three categories / delivery models: • Infrastructure-as-a-Service (Iaas), • Platform-as-a-Service (Paas) (GoogleApps are examples of PaaS), & • Software-as-a-Service (Saas). • Data and software packages are stored in servers. The cloud computing structure allows access to information as long as an electronic device has access to the web. This allows employees to work remotely.
Based on the definition, a typical cloud environment consists of a set of hardware, software, and manageability interfaces, which collectively deliver computing as a service with the following four essential characteristics: 1. Elastic and dynamic scaling (A key benefit of cloud computing is the ability to add and remove capacity as and when it is required. This is often referred to as elastic scale. Being able to add and remove this capacity can dramatically reduce the total cost of ownership for certain types of applications, for some applications cloud computing is the only economically feasible solution to the problem); SCALABILITY - ability of a system to increase the workload on its current hardware resources (scale up); ELASTICITY - ability of a system to increase the workload on its current and additional (dynamically added on demand) hardware resources (scale out); 2. Self-service provisioning and management; 3. Self-management and automatic scaling; 4. Cost effectiveness.
Characteristics It is : • sold on demand (automatic approach to scaling in cloud environments), typically by the minute or the hour; • it is elastic - a user can have as much or as little of a service as they want at any given time; and • the service is fully managed by the provider (the consumer needs nothing but a personal computer and the Internet access).
These essential characteristics have different meanings to different types of cloud stakeholders. • In order to ensure common understanding, potential cloud stakeholders are characterised into four general roles: • End Users; • Cloud Service Providers (CSPs); • Cloud Tool Providers (CTPs); • Cloud Application Vendors (CAVs).
The definition of these roles and the role-specific implications of individual characteristics:
Software as a Service (SaaS) is a cloud delivery model that has existed for a long time. • A SaaS is an implementation of a business application or process that is developed on a cloud platform and hosted in a cloud infrastructure. • SaaS providers deliver domain-specific applications or services over the Internet and charge end users on a pay-per-usage basis. • A Platform as a Service (PaaS) cloud lies directly upon an IaaS layer with a solution stack summarisingeverything required for the whole software engineering lifecycle (i.e. design, development, debugging, testing, and deployment). • The potential consumers of a PaaS cloud service are therefore software developers and testers. • Most PaaS vendors lock developers into particular development platforms and debugging tools, and do not allow direct communication with lower computing infrastructures, although certain programming APIs might be provided with limited functionalities of infrastructure control and management. Service Delivery Models
Cloud services that deliver infrastructure resources (i.e. compute, storage, networking, and operating systems) as a service are known as Infrastructure as a Service (IaaS). • IaaS model allows customers to start a new project quickly by renting computing resources. The key characteristic of an IaaS cloud is elasticity and scalability, enabling computing resources to scale up and down. • Most IaaS cloud providers offer scalability under customers’ control with direct self-service interfaces, through which consumers can request to scale, control, and manage computing resources. • An IaaS cloud is also referred as a resource cloud.
According to the different types of resource offered, IaaS cloud can be further divided into three sub-categories: • Computing as a Service (CaaS) offers customers access to raw computing power on virtual servers or virtual machine instances. CaaS provides self-service interfaces for on-demand provisioning and management (i.e. start, stop, reboot, destroy) of virtual machine instances. • A CaaS provider may also provide self-management interfaces for auto-scaling and other automatable management facilities. • Storage as a Service offers online storage services allowing on-demand storing and access to data on third-party storage spaces. • Database-as-a-service (DaaS) includes standardised processes for accessing and manipulating (i.e. write, update, delete) data through database management systems (DBMS) that are hosted in the cloud.
Deployment Models • A cloud system (IaaS, PaaS, and SaaS) can be deployed using the following three main models. • A public cloud sells services to anyone on the Internet. (e.g. currently Amazon Web Services is the largest public cloud provider.) • A private cloud is a proprietary network or a data centre that supplies hosted services to a limited number of people. • When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services. • A hybrid cloud is needed when private clouds run out of capacity. It is a composition of two or more clouds that remain unique entities but are bound together.
The advantages of using Public cloud computing include: The disadvantages include: • Efficient storage and computing services. • Inexpensive, since all the virtual resources whether application, hardware or data are covered by the service provider. • Easy connectivity to servers and information sharing. • Assures appropriate use of resources as the users are required to pay only for the services they require. • Highly reliable. • Widespread availability irrespective of geographical region. • Sets the business people free from the trouble of buying, managing and maintaining all the virtual resources , the cloud server does it all. • Public cloud empowers employees and enables them to become productive even when outside the office. The SaaS model ensures that corporations save on IT expenditures while delivering the flexibility of productivity software on the cloud. • Variety of applications; E.g. Microsoft – Amazon incompatibility; • Security issue.
Cloud Computing Segments Cloud computing is broken down into three segments. Each segment serves a different purpose and offers different products for businesses & individuals: • Application • Storage • Connectivity
Cloud Computing Glossary • Cloud - A metaphor for a global network, first used in reference to the telephone network and now commonly used to represent the Internet. • Cloud provider – makes storage or software available to others over a private network or public network (like the Internet). • Cloud Storage – also called online storage, Internet storage or hosted storage, it is a data storage management solution that enables individuals or organisations to store their data on the Internet using a service provider, rather than storing the data locally on a physical disk, such as a hard drive or tape backup. • Elastic computing –The ability to scale resources both up and down as needed. To the consumer, the cloud appears to be infinite, and the consumer can buy as much or as little computing power as they need. • Hybrid cloud – A computing environment that combines both private and public cloud computing environments. • Hosted application – An Internet-based or Web-based application software programme that runs on a remote server and can be accessed via an Internet-connected PC or thin client.
Infrastructure as a Service (IaaS) – Cloud infrastructure services or “Infrastructure as a Service (IaaS)” delivers computer infrastructure, typically a platform virtualisation environment, as a service. Rather than buyingservers, software, data centre space or network equipment, clients buy those resources as a fully outsourced service. • IT – is the study, design, development, implementation, support and management of the computer-based information systems, particularly software applications and the computer hardware on which they operate. IT is responsible for the use of computers and software to convert, store, protect, process, transmit and retrieve information. • Private Cloud –Infrastructure as a Service (IaaS) delivered to a restricted set of customers, usually within an organisation. • Platform as a Service (PaaS) – Cloud platform services or “Platform as a Service (PaaS)” deliver a computing platform and /or solution stack as a service, often consuming cloud infrastructure and sustaining cloud applications. It facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers. • Public Cloud – Infrastructure as a Service (IaaS) delivered to an unrestricted set of customers.