Cloud Computing Lecture 1

What is PaaS?

A PaaS abstracts away the interaction with the bare metal of the system, and thus lets software developers can concentrate on writing the application. You don't need to directly administer the virtual operating systems. *This simplification generally comes at the cost of less flexibility and the requirement to code in the specific languages supported. "Platform as a Service allows users to create software applications using tools supplied by the provider. PaaS services can consist of preconfigured features that customers can subscribe to; they can choose to include the features that meet their requirements while discarding those that do not. Consequently, packages can vary from offering simple point-and-click frameworks where no client side hosting expertise is required to supplying the infrastructure options for advanced development. The infrastructure and applications are managed for customers and support is available. Services are constantly updated, with existing features upgraded and additional features added. PaaS providers can assist developers from the conception of their original ideas to the creation of applications, and through to testing and deployment. This is all achieved in a managed mechanism. As with most cloud offerings, PaaS services are generally paid for on a subscription basis with clients ultimately paying just for what they use. Clients also benefit from the economies of scale that arise from the sharing of the underlying physical infrastructure between users, and that results in lower costs. Below are some of the features that can be included with a PaaS offering: Operating system Server-side scripting environment Database management system Server Software Support Storage Network access Tools for design and development Hosting Software developers, web developers and businesses can benefit from PaaS. Whether building an application which they are planning to offer over the internet or software to be sold out of the box, software developers may take advantage of a PaaS solution. For example, web developers can use individual PaaS environments at every stage of the process to develop, test and ultimately host their websites. However, businesses that are developing their own internal software can also utilise Platform as a Service, particularly to create distinct ring-fenced development and testing environments. Below are some of the benefits of PaaS to application developers: They don't have to invest in physical infrastructure; being able to 'rent' virtual infrastructure has both cost benefits and practical benefits. They don't need to purchase hardware themselves or employ the expertise to manage it. This leaves them free to focus on the development of applications. What's more, clients will only need to rent the resources they need rather than invest in fixed, unused and therefore wasted capacity. Makes development possible for 'non-experts'; with some PaaS offerings anyone can develop an application. They can simply do this through their web browser utilising one-click functionality. Salient examples of this are one-click blog software installs such as WordPress. Flexibility; customers can have control over the tools that are installed within their platforms and can create a platform that suits their specific requirements. They can 'pick and choose' the features they feel are necessary. Adaptability; Features can be changed if circumstances dictate that they should. Teams in various locations can work together; as an internet connection and web browser are all that is required, developers spread across several locations can work together on the same application build. Security; security is provided, including data security and backup and recovery. In summary, a PaaS offering supplies an operating environment for developing applications. In other words, it provides the architecture as well as the overall infrastructure to support application development. This includes networking, storage, software support and management services. It is therefore ideal for the development of new applications that are intended for the web as well as mobile devices and PCs."

Cloud computing can mean many things but what are the four categories it falls into?

Big data processing Web 2.0 Utility computing Everything as a service

What are the 3 classifications of cloud?

Infrastructure as a service Platform as a service Software as a service

What is SaaS?

SaaS is often referred to as software-on-demand and utilising it is akin to renting software rather than buying it. With traditional software applications you would purchase the software upfront as a package and then install it onto your computer. The software's licence may also limit the number of users and/or devices where the software can be deployed. Software as a Service users, however, subscribe to the software rather than purchase it, usually on a monthly basis. Applications are purchased and used online with files saved in the cloud rather than on individual computers. No additional hardware costs; the processing power required to run the applications is supplied by the cloud provider. No initial setup costs; applications are ready to use once the user subscribes. Pay for what you use; if a piece of software is only needed for a limited period then it is only paid for over that period and subscriptions can usually be halted at any time. Usage is scalable; if a user decides they need more storage or additional services, for example, then they can access these on demand without needing to install new software or hardware. Updates are automated; whenever there is an update it is available online to existing customers, often free of charge. No new software will be required as it often is with other types of applications and the updates will usually be deployed automatically by the cloud provider. Cross device compatibility; SaaS applications can be accessed via any internet enabled device, which makes it ideal for those who use a number of different devices, such as internet enabled phones and tablets, and those who don't always use the same computer. Accessible from any location; rather than being restricted to installations on individual computers, an application can be accessed from anywhere with an internet enabled device. Applications can be customised and whitelabelled; with some software, customisation is available meaning it can be altered to suit the needs and branding of a particular customer.

What is IaaS?

Supplies virtual images of different OS's. They can be tailored by developers to run any custom or packaged application. Users use the instances and when they need it. "In the case of IaaS the computing resource provided is specifically that of virtualised hardware, in other words, computing infrastructure. The definition includes such offerings as virtual server space, network connections, bandwidth, IP addresses and load balancers. Physically, the pool of hardware resource is pulled from a multitude of servers and networks usually distributed across numerous data centres, all of which the cloud provider is responsible for maintaining. The client, on the other hand, is given access to the virtualised components in order to build their own IT platforms." Infrastructure as a Service (IaaS) is one of the three fundamental service models of cloud computing alongside Platform as a Service (PaaS) and Software as a Service (SaaS). As with all cloud computing services it provides access to computing resource in a virtualised environment, "the Cloud", across a public connection, usually the internet. In the case of IaaS the computing resource provided is specifically that of virtualised hardware, in other words, computing infrastructure. The definition includes such offerings as virtual server space, network connections, bandwidth, IP addresses and load balancers. Physically, the pool of hardware resource is pulled from a multitude of servers and networks usually distributed across numerous data centers, all of which the cloud provider is responsible for maintaining. The client, on the other hand, is given access to the virtualised components in order to build their own IT platforms. In common with the other two forms of cloud hosting, IaaS can be utilised by enterprise customers to create cost effective and easily scalable IT solutions where the complexities and expenses of managing the underlying hardware are outsourced to the cloud provider. If the scale of a business customer's operations fluctuate, or they are looking to expand, they can tap into the cloud resource as and when they need it rather than purchase, install and integrate hardware themselves. The following are salient examples of how IaaS can be utilised by enterprise: Enterprise infrastructure; by internal business networks, such as private clouds and virtual local area networks, which utilise pooled server and networking resources and in which a business can store their data and run the applications they need to operate day-to-day. Expanding businesses can scale their infrastructure in accordance with their growth whilst private clouds (accessible only by the business itself) can protect the storage and transfer of the sensitive data that some businesses are required to handle. Cloud hosting; the hosting of websites on virtual servers which are founded upon pooled resources from underlying physical servers. A website hosted in the cloud, for example, can benefit from the redundancy provided by a vast network of physical servers and on demand scalability to deal with unexpected demands placed on the website. Virtual Data Centers (VDC); a virtualised network of interconnected virtual servers which can be used to offer enhanced cloud hosting capabilities, enterprise IT infrastructure or to integrate all of these operations within either a private or public cloud implementation. A typical Infrastructure as a Service offering can deliver the following features and benefits: Scalability; resource is available as and when the client needs it and, therefore, there are no delays in expanding capacity or the wastage of unused capacity No investment in hardware; the underlying physical hardware that supports an IaaS service is set up and maintained by the cloud provider, saving the time and cost of doing so on the client side Utility style costing; the service can be accessed on demand and the client only pays for the resource that they actually use Location independence; the service can usually be accessed from any location as long as there is an internet connection and the security protocol of the cloud allows it Physical security of data centre locations; services available through a public cloud, or private clouds hosted externally with the cloud provider, benefit from the physical security afforded to the servers which are hosted within a data centre No single point of failure; if one server or network switch, for example, were to fail, the broader service would be unaffected due to the remaining multitude of hardware resources and redundancy configurations. For many services if one entire data center were to go offline, nevermind one server, the IaaS service could still run successfully.

What does Pooled Resources mean?

• Available to any subscribing user. • Commodity hardware in massive data warehouses.

What does Automation mean?

• Building, deploying, configuring, provisioning, and moving, all without manual intervention AMI - Amazon Machine Image, encrypted and signed machine image that runs a virtual server environment. AMI's can be public or private. AMI's can be stored in Amazon's S3. (Simple storage service)

What does Metered billing mean?

• Charged only for what you use. Reduces cost.

What is cloud computing in terms of Utility computing?

• Computing resources as a metered service. • Dynamically position vertical machines • Uniform • Pay as you go • Scale up or down as much as you like

What does Virtualisation mean?

• Decouples user from implementation. A virtual server forces users not to worry about the servers physical server or their location. All they need to know is their application and the service level agreement • Decreases server provisioning to months to minutes. For a company to install, config and deploy a server it can take 1-3 months. By using a virtual server this can take minutes to hours until the application can be deployed. • Breaks software pricing and licensing. Data centers no longer charge for entire servers. Only the used amount is charged.

What does Elasticity mean?

• Dynamically scales without Capital Expenditure (expenditures that alters the future of the business)

What are the benefits of cloud computing?

• Economical, change from CAPEX to OPEX (operational expense). • Agility, do not have to buy servers. • Efficiency, fast start up. • Security, rather than managing your own security that can be costly and time consuming large companies such as Amazon and Google will have experts that work on this and take care of it for you. They most likely have significant experience in this field. • Allows developers to focus on the core application • Faster time to the market • Higher availability

When should you NOT use cloud?

• Legacy systems • Applications using real time or mission critical scenarios. Realtime stock update. • Applications dealing with confidential data. Who is on benefits.

When is it a good idea to use a cloud?

• Limited lifetime requirement or short-term need. Payroll • Scale variability or volatility Video streaming • Nonstrategic applications or low organizational value. Ask what does this mean?

What are the 5 principals of cloud computing?

• Pooled Resources • Virtualisation • Elasticity • Automation • Metered Billing

What are the 4 different models of Cloud?

• Public • Private • Community • Hybrid

What is cloud computing in terms of web 2.0?

• Rise of netbooks tablets and smart phones. • Interactive web applications - Facebook, google youtube. The ability to comment tag. • Browser is the OS

What is cloud computing in terms of Everything as a service?

• Software • Platform • Infrastructure

What is cloud computing in terms of Big Data processing?

• User generated content such as YouTube, Instagram • User behavior data, dating apps and shopping apps, google search logs • Data science, mining data, machine learning.