Introduction to Cloud Computing

What is the Cloud?Lots of definitions can be given when talking about Cloud Computing as it can be viewed in different ways. IQ Cloud explain it as an "approach to computing that's about Internet scale and connecting to a variety of devices and endpoints." That's a bit vague and wooly right?(http://www.iqcloud.net/cloud-computing/)PCMag UK explain it as "storing and accessing data and programs over the Internet instead of your computer's hard drive." That means the Cloud is "just a metaphor for the Internet." (http://uk.pcmag.com/networking-communications-software-products/16824/feature/what-is-cloud-computin...)Whilst the National Institute of Standards and Technology (NIST) define Cloud Computing as a "model for enabling ubiquitous, convenient, on-demand network access to a shared 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." (http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-145.pdf)With all these definitions in mind, I can define Cloud Computing as about delivering self-service computing, on demand, managed on your behalf, in a way that scales up (and down) to meet your needs and where you only pay for the resources you need. Essentially, outsourcing computing so an organisation can focus on business objectives.

Why the Cloud?Why would an organisation want to use the Cloud? There are many reasons why Cloud Computing is seen as a step forward in technology. However, three distinct factors need to be taken into consideration; speed, scale and economics.So let's start with speed. The implementation of Cloud Computing has allowed many organisations to rapidly setup environments in order to drive business priorities. Essentially, Cloud Computing allows organisations to leave the worry of managing IT Systems in the hands of their providers whilst they focus on their aims and priorities in order to drive the business forward.Secondly, there is scale. Cloud Computing is seen as an elastic entity due to how it can be scaled to meet peak demands with robust redundancy. This means that all their resources don't have to be running 24/7 which in turn, saves money. Instead the amount of resources used rises and drops depending on the demand to use them.Finally, we have the economics behind Cloud Computing which essentially sums up the two previous factors. Due to how rapidly environments can be set up and how control over IT resources is handed over to the provider, the daily activities conducted by an organisation increases. Furthermore, the elastic nature of Cloud Computing means IT resources are used more efficiently, which in turn, reduces cost.

Cloud Computing as a UtilityWhen you think of a utility, you may picture electricity and gas companies like British Gas or EDF Energy. However, Cloud Computing can also be seen as a utility in terms of computer power instead of electricity or water.When an organisation implemented a Cloud Computing solution, they are essentially paying for a computing resources. Which is then deployed on their behalf and if they need more power, then they simply buy more.This is incredibly beneficial for Cloud Service developers who in the past had to consider the deployment of their service. However, now they only have to focus on making the service before handing it over to their provider who will then deploy it for them.On the previous slide, I talked about elasticity. This term is thrown around quite a bit in regards to Cloud Computing as it allows an organisation to automate resource scaling if demand goes, as well as down. This leads us on to the next topic of Cloud Computing Patterns.

Cloud Computing PatternsThe demand for IT resources constantly changes and this can pose a problem in terms of cost. Why use up all your IT resources if the demand for them is low? The aspect of elasticity within Cloud Computing gets around this with a wide variety of patterns.Static WorkloadA static workload can be applied if an organisation's IT resources have an equal utilisation over time.

Periodic WorkloadA periodic workload can be applied if an organisation's IT resources experience a peaking utilisation at reoccurring time intervals.

Once-in-a-Lifetime WorkloadA once-in-a-lifetime workload can be applied if an organisation's IT recourses experience equal utilisation over time but at risk of being disturbed by a strong peak occurring only once.

Unpredictable WorkloadAn unpredictable workload can be applied if an organisation's IT resources experience a random and unforeseeable utilisation over time.

Continuously Changing WorkloadA continuously changing workload can be applied if an organisation's IT resources experience a utilisation that is growing or shrinking constantly over time.

Cloud Computing vs. Traditional ComputingWe previously explained that Cloud Computing is different to Traditional Computing. Cloud Computing is not about your hard drive. When storing data or running programs from the hard drive, that's referred to as local storage and computing. All the devices are physically close to you which results in a fast and easy experience.The difference with Cloud Computing is you can access your data or programs over the Internet. This can be done anywhere and anytime, considering you have an online connection. A main downfall with with Traditional Computing is if the user has to access data stored on a separate system, they need to store it in an External Storage Medium.Cloud Computing gets around this because the user only need a system with an Internet connection and a Cloud User Interface. Data is not constrained to any one system or network whilst Cloud services aid in reducing the space and cost needed for data storage.Going back to the aspect of elasticity, Cloud Computing allows an organisation to pay for as much capacity as they need. Traditional Computing, on the other hand, demands more software and hardware, but once you overreach your storage capacity, you need to install more.

Cloud Computing vs. Traditional ComputingAs you can see from the diagram below, more hardware is required in the form of Switches and Routers, before a system can be connected to the Internet.

Cloud Computing, on the other hand, requires less hardware and an Internet connection leads a direct route to a wide variety of services to be accessed by an organisation.

Benefits of Cloud Computing Cost of servers and equipment Software updates Cost of running Cost of related services such as cooling and UPS Reduced downtime Cuts operational costs Allows IT department to focus on strategic projects instead of the datacentre Remote workers can login and access applications from anywhere Another company hosts the applications

DatacentersA datacentre is a enormous building where a collection of servers are stored. Applications and data is then hosted on these servers.A datacentre refers to a single geographical location in which servers are housed with hundreds of servers to a room/crate. This is very expensive and hot!A move to rack mounted servers has reduced costs and space, however, in recent years this has been moved to blade servers and virtualisation.