Cloud Computing Module 2-3 PDF

Module 2-3. Cloud Computing OBJECTIVE 3a. Identify basic facts and terms about cloud computing. - Definition - Characteristics - Service Model Types - Deploymen Cloud makes reference to two concepts, abstraction and virtualization: **Abstraction** A process in which specific details...

Module 2-3. Cloud Computing OBJECTIVE 3a. Identify basic facts and terms about cloud computing. - Definition - Characteristics - Service Model Types - Deploymen Cloud makes reference to two concepts, abstraction and virtualization: **Abstraction** A process in which specific details are hidden or ignored to simplify or generalize something (i.e. location of a server). "Serverless abstraction" is the notion in cloud computing that software can be totally separated from the hardware servers that it runs on. Users can execute an application without having to provision and manage the server where it resides. **Virtualization** The process in which software manages hardware resources of physical hosts, so those resources can be used more efficiently by multiple virtualized guest systems. **CHARACTERISTICS** The characteristics of cloud computing include on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. **On-Demand Self-service** A consumer can get access to computing capabilities such as storage and server time as required, without any human interaction with a cloud service provider. Cloud service providers providing on-demand self- services include companies such as Google, Microsoft, Amazon Web Services (AWS), and IBM. **Broad Network Access** This means that the hosted application should be reachable to any network device (laptop, desktop, smartphone, tablet device, etc.). Cloud capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick clients. The consumers just need to have an in-built web browser to connect to the cloud service provider. It gives an advantage to users who have less powerful devices. This mobility is particularly attractive for businesses, as during business hours or on off time, the user can be up to date. **Resource Pooling** The cloud enables users to enter and use data within business management software hosted on the cloud at the same time, from any location and at any time. The computing resources are pooled to serve multiple consumers using a multitenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. The user is usually unaware of the exact location of cloud provider resources. **Measured Service** This is the straightforward idea that the consumers only pay for the resources they consume. The cloud provider can measure the storage levels, processing, and bandwidth used and the consumers are billed appropriately. The resources being used can be monitored and controlled from both the consumer\'s side and cloud provider\'s side, resulting in transparency. Cloud computing services use a metering capability which helps to control and optimize resource use. This implies that just like an electricity bill, the IT services are also charged according to use. **Rapid Elasticity** The cloud is flexible and scalable. Consumers can quickly and easily add or remove software features and other resources to suit their immediate business needs. Cloud services can be rapidly and elastically provisioned automatically. **SERVICE MODEL TYPES** Cloud service providers offer services that can be grouped into three categories i.e. Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). **Software as a Service (SaaS)** In SaaS, different type of applications are offered to the customer as a service on-demand. On a cloud a single instance of the service is run and multiple end-users can access the services simultaneously. The customers need not invest in servers or software licenses, while for the provider the costs are lowered, as only a single application needs to be hosted and maintained. Various benefits and challenges of SaaS are shown in Table 2.1. Presently, SaaS is offered by companies such as Google, Salesforce, and Microsoft. **Platform as a Service (PaaS)** In PaaS, a layer of software or development environment is encapsulated and offered as a service over which other higher level of services can be built. The customer can build their own applications on the provider\'s infrastructure. PaaS delivers a computing platform and/or solution stack as a service, often consuming cloud infrastructure and sustaining cloud applications. Developers are less constrained by resources such as memory and processing power. They are able to use existing skills with Microsoft Visual Studio and Microsoft. NET to build compelling applications and services that are hosted within the cloud. Customized applications and tools are built that improve developer productivity on behalf of the entire engineering organization. Google\'s App Engine, Force.com, etc. are some of the popular PaaS examples. Some of the PaaS benefits and challenges. **Infrastructure as a Service (IaaS)** IaaS provides basic computing capabilities and storage as standardized services over the network. Servers, storage systems, data center space, networking equipment, etc., are pooled and are available to the users. IaaS has the capability to provision processing, networks, storage and other fundamental computing resources where the consumer is able to deploy and run software. This may include both applications and operating systems. Companies can choose to optimize their infrastructure by adopting an IaaS. The customer typically deploys his own software on the infrastructure provided by the IaaS provider. Some common examples are Amazon, GoGrid, 3 Tera, etc. Some of the benefits and challenges of IaaS. **DEPLOYMENT MODEL TYPES** With cloud computing technology, large pools of resources can be connected through private or public networks. This technology provides dynamically scalable infrastructure and simplifies infrastructure planning for cloud-based applications, data and file storage. An enterprise can choose to deploy applications on public, private, hybrid, community, federated, or personal clouds. **Public Cloud** The cloud infrastructure is open for use by the general public. It may be owned, managed and operated by a business, academic or government organization. Public cloud exists on the premises of the cloud provider. They deliver superior economies of scale to customers as the infrastructure costs are spread among a mix of users, giving each individual client an attractive low-cost, \"pay-as-you-go\" model. The infrastructure pool is shared by all the customers with limited configuration, security protections, and availability diversity. The main advantage of a public cloud is that they may be larger than an enterprise cloud, thus providing scalability seamlessly on demand. **Private Cloud** This is built exclusively for a single enterprise. The main aim of private cloud is to address concerns on data security and offer greater control, which is absent in a public cloud. There are two types of private cloud: **On-premise Private Cloud**: On-premise private clouds, even called internal clouds, are hosted within one\'s own data center. This model is limited in size and scalability but has more standardized processes and protection. IT departments would also need to acquire the capital and operational costs for the physical resources. This is best suited for applications which require complete security, control, and configurability of the infrastructure. **Externally hosted Private Cloud**: This type of private cloud is hosted externally with a cloud provider. It is facilitated with an exclusive cloud environment with a full guarantee of privacy and security. This is best suited for enterprises that don't prefer a public cloud due to the sharing of physical resources. Some of its important features are listed below: - Within the boundaries (firewall) of the organization. - All the advantages of a public cloud. - Reduced operational cost. - Fine-grained control over resources. - More secure as they are internal to organization. - Can schedule and reshuffle resources based on business demands. - Development requires hardware investments and in-house expertise. - Ideal for applications related to tight security and regulatory concerns. - Cost might exceed that of public clouds. - Has to be managed by the enterprise - **Hybrid Cloud** A hybrid cloud is a combination of private and public clouds. With a hybrid cloud, service providers can utilize third party cloud providers in a full or partial manner, thus increasing the flexibility of computing. The hybrid cloud environment is well suited for providing on-demand, externally provisioned scale. The ability to amplify a private cloud with the resources of a public cloud can be used to manage any unexpected growth in the workload. **Community Cloud** Community cloud is a multi-tenant cloud service model, which is shared among various organizations and is managed, governed and secured commonly by all the participating organizations or by a third party. It is a hybrid form of private cloud built and operated specifically for a targeted organization and communities. These communities have similar requirements and their ultimate goal is to work together to achieve their business objectives. The objective of community clouds is to have participating organizations realize the benefits of a public cloud along with the added level of security, privacy and policy compliance usually associated with a private cloud. The community clouds can be set either off-premises or on-premises. **Personal Cloud** A small server in a home or small network that can be accessed over the internet, similar to private cloud is a personal cloud. In personal cloud the user decides which data to store, and which to delete or modify. While the data is accessible over the network, nobody can access or use your data without your permission. User decides which data to share with whom and when to revoke that privilege. **BENEFITS** The major advantages of cloud computing are described below. **Cost Efficient** Cloud computing is probably the most cost effective way to use, maintain, and upgrade applications. Traditional desktop software costs a lot. Adding up the licensing fees for multiple users in a company can prove to be very expensive. The cloud, on the other hand, is available at much cheaper rates and can significantly lower the company\'s IT expenses (pay-as-you-go and other scalable options). **Unlimited Storage** Storing information on the cloud provides an almost unlimited storage capacity. **Backup and Recovery** Since all the data is stored on the cloud, backing it up and restoring it is relatively easier than storing the data on a physical device. The entire process of backup and recovery becomes much simpler than other traditional methods. **Automatic Software Integration** Software integration is usually something that occurs automatically on the cloud. This means that cloud users don't have to make additional efforts to customize and integrate their applications. **Easy Access to Information** Once users register on the cloud, they can access their information from anywhere via an Internet connection. This convenient feature lets users overcome time zone and geographic location issues. **Quick Deployment** Cloud computing gives the advantage of quick deployment. The entire system can be fully functional in a matter of a few minutes. Of course, the amount of time taken depends on the kind of technology that is needed for the business. **Scalability** Cloud computing makes it easier for an organization to scale their services according to the demand of clients. The consumer business can scale up or scale down the operation and storage needs quickly to suit the situation, allowing flexibility as the needs change. Rather than purchasing and installing expensive upgrades, the cloud service provider can handle this for the consumer. Using the cloud, the consumer frees up their time so that they can get on with running their business.