The History Of Distributed Computing Systems

Published Date: 02 Nov 2017

MscComp

Distributed Computing Systems

Tutor: Richard Hall

Student ID: 10456384

Submitted By: Rayees Ahmed Abdul Anam

Introduction to clouds

Cloud computing denotes to applications and services presented over the Internet. These facilities are offered from data centers around the globe, which together are referred to as the "cloud." This symbol represents the intangible, yet collective nature of the Internet.

Cloud computing is ideal for supporting suitable and on-demand network access for sharing a group or computing resources like networks, servers, storage, applications and services which helps in minimizing management effort or interaction of service provider.

In this resources are retrieved on internet through web applications rather than from a direct server. Data and required software are stored in servers. As long as an electronic device has web access the information can be accessed.

The cloud symbol was used to denote the differentiation point between that which was the responsibility of the provider from that of the user. Cloud computing ranges this margin to cover servers as well as the network infrastructure.

How it works

To know exactly functioning of cloud computing, consider the cloud contains three layers -mainly the back end layers and the front end layers. The front layers are the portions which we see and interact with. For example, when using Facebook account software running on the front end of the cloud. The back end contains the hardware and the software architecture that provides the data seen on the front end.

Clouds use a network layer to connect to users’ end point devices with computers or smart phones, to resources that are centralized in a data center. Users can access the data center via a company network or the internet or with both. Clouds can also be accessed from any locality, letting traveling employees to access their business systems on demand.

Applications running on the cloud make the most of the flexibility of the computing power offered. The computers are set up to work together and it seems as if the applications were running on one particular machine. Major advantage of cloud computing is the flexibility. It allows the user to use the amount of resources from cloud without any specific hardware for the job being.

Characteristics of cloud computing

The following are considered to be some of characteristics of cloud computing

Dynamically Scalable

Device independent

Task Centric

Dynamically Scalable

Cloud computing is dynamically scalable since users only have to use the amount of online computing resources they actually want.

Device Independent:

As the resources can be retrieved from any computer that has an Internet connection and a web browser, whether it is desktop, laptop PC, a netbook, tablet, smartphones or any other kind of cloud access device, cloud computing is device independent. Such device independency is also a remarkable feature of cloud computing because users can move between their devices without worrying that they can access to their files.

Task Centric:

Cloud computing model is based entirely around what users want to achieve, relatively than software, hardware and network infrastructure. Neither users have to purchase or install anything before using a cloud computing resource nor do they have to maintain or pay for anything during periods in which no resources are being used.

Types of cloud

There are three types of cloud

Public

Private

Hybrid

Community

Public Cloud:

The computing infrastructure is located at the company which offers cloud service. The customers have no physical contact with the infrastructure. It uses shared resources high performances is expected and are exposed to various attacks.

Public cloud computing is the most widely adopted class as well as the most understood. It’s often considered the standard model of cloud computing. The two most popular public cloud computing service providers are Amazon web and Google apps

Private Cloud:

The cloud infrastructure is provided for an organization or one customer. It is not shared with other organization. They have physical control over infrastructure if the cloud is set up on premise of the organization. Security and Control level is high when private cloud is used.

Hybrid Cloud:

It means, using both private and public clouds, subjected to their purpose.

For example, public cloud may be used to interact with customers and their data are kept secured through a private cloud.

Community Cloud:

Community cloud indicates an infrastructure which mutual between organizations, for data sharing and data management concerns. Community clouds can be located both on and off the premises.

Service Models:

Inside the cloud computing environment there are three types of Service model

Software as service

Platform as service

Infrastructure as service

Software as a Service (SaaS)

It contains end-user applications provided as a service, rather than as outdated, on-premises software. Users can access various software applications on a pay-per-use basis rather than buying licensed programs which are often very expensive.

SaaS provides users with many benefits like

general cloud computing

advantages of dynamic scalability

any device independence

application usage without fixed cost

Are collaborative and allow multiple users to share documents at same time.

The common example of SaaS is Salesforce.com, which offers a customer relationship management (CRM) system accessible via the Internet.

Platform as a Service (PaaS) 

It offers an application platform or middleware as a service on which developers can build and organize custom applications. Common explanations provided in this level range from

APIs and tools to database

Business process management systems

Security integration,

It allows developers to build applications and run them on the infrastructure that the cloud service provider maintains. Microsoft's Windows Azure platform services are example for PaaS solutions at this middleware tier.

Infrastructure as a Service (IaaS)

 Mainly includes the hardware and technology for

computing power

storage

operating systems

other infrastructure

It is delivers on-demand services rather than as dedicated, on-site resources such as the Amazon Elastic Compute Cloud (Amazon EC2) or Amazon Simple Storage Service (Amazon S3).

Designing Cloud

The modules required to build the cloud are similar to the components required to build a traditional architecture; the difference is how they integrate, communicate, and act.

Cloud computing has changed from a single server being provided for a single customer, to a hosting provider and then to a business continuity and disaster recovery provider.

Now we have exceptional levels of virtualization of hardware, software, network, and storage and are on the verge of putting it all together.

Traffic and computing systems regularly breakdown processing into two discrete components: the data plane and the control plane.

The data plane is the basic connectivity that handles traffic flow to and from destinations. The control plane, instead, is more concerned with handling that data in response to context and policy; it changes the "how" of the data plane.

The dynamic control pane must be able to Intercept traffic as it traverses the cloud, Interpret the data, and Instruct the cloud architecture on how to efficiently connect user’s appropriate application.

Cloud computing Architecture:

Challenges while implementing cloud

Satisfying Management:

First challenge is to convince the management about the cloud, benefits of setting up a cloud for the organization and how it will improve for the grow of the

Selecting cloud

For setting up an effective cloud it is more important to choose the one which suits the organization. Larger companies go for Private cloud; smaller companies may use public cloud for hosting. Some prefer using hybrid cloud (public and private).

Guidance from Experts:

The governmental and internal protocols should be followed during implementation of cloud. Guidance can be received from professionals who are aware of the terms and conditions concerning cloud implementation and data security.

Dealing with provider:

Selecting service provider is one of the major issues while implementing cloud. The service provided should be fast and without interruption. Should have complete knowledge of what service is offered by the provider, security protocols, and compensations.

Data security:

Generally companies work on strict data security guidelines to prevent hacking and invest severely on upgraded software and hardware. The service providers must have operative data backup plans to recover data in case of any disasters.

Data portability:

Concerns regarding data portability can seriously threaten smooth transition to cloud. Ensuring data portability is essential in cloud computing. Frequently clients criticize almost being locked in with service providers and not being able to switch freely.

Distributed computing vs. Cloud computing

A distributed system is made up of multiple computers shared through a network. Local memory of those computers is used .All computers in the distributed system interacts with other to achieve a process done.

On the other hand, different users at each computer may have separate requirements and the distributed system will do the synchronization of sharing resources (or aid connect with other nodes) to achieve their individual tasks. Nodes interconnect using message passing.

Distributed computing can also be known as using a distributed system to solve a single large problem by breaking it up to tasks, each of which is computed in separate computers of the distributed system. Usually, toleration mechanisms are in place to overcome individual computer failures.

Differences:

Distributed computing comprises of dividing a larger problem into smaller slices and having multiple networked computers process the slices.

Cloud computing usually refers to providing a service through internet. The services varies from business software to documents that is accessed via the web to off-site storage or computing resources

Cloud computing delivers many kinds of resources as services, mainly over the internet, while distributed computing is the concept of using a distributed system consisting of many self-governed nodes to solve a very large problem (that is usually difficult to be solved by a single computer).

Web hosting packages

Web hosting provides a fixed server or a portion of a single server, where cloud computing offers the benefit of many servers all working together as one. Particular website or application may only need one small portion of a single server, and therefore dedicated server is not required.

The best type of web hosting is dedicated hosting. A web administrator has more control over a dedicated server which is more secure compared to a shared server. In addition to this, dedicated hosting is more dependable because a server administrator is self-sufficient and can improve page loads by correcting variables like page load speed and server allocation.

The disadvantage of web hosting is the necessity to monitor, install, upgrade and configure programs, add sites deal with potential hacks, and troubleshoot systems.it requires a System administrator with more skills to implement a website on a webserver.

Nowadays, several businesses have been making use of cloud computing. One advantage of cloud computing is that when a company’s information is stored in "the cloud" overall expenses are drastically reduced

If the importance is to minimize working expenses, cloud computing is for best. However, if you want more security for complex data, web hosting is the better option.

Clouds Advantages:

Flexibility

It has the ability to meet the demands of the business needs and it’s the reason for moving towards cloud computing

Disaster recovery

If a company relies its business on cloud services, they no longer require huge disaster and recovery plans. Because every problem will be sorted out by the service providers.

Automatic software updates

Software can be easily updated by the customers and it is done by the cloud service providers along with maintenance.

Increased collaboration

Employees can sync their documents from various places at the same time and follow their co employees and receive updates in real time.

Work from anywhere

As long as the employees have internet access they can work from anywhere around the globe and this flexibility provides upper hand for the cloud computing.

Document control

Cloud computing keeps every file in one central location and everyone works off of one central copy. Employees can even chat to each other whilst making changes together.

Competitiveness

Smaller companies with cloud services act fast and are able to compete with established companies

Environment friendly

Businesses using cloud computing only use the server space they need, which decreases their carbon footprint. Using the cloud results in at least 30% less energy consumption and carbon emissions than using on-site servers

Conclusion

Nevertheless, large companies are cautious of cloud computing. There is a lack of faith between these companies and storage providers. Even if they trust their storage provider, they still have security worries. Because, there is always the threat of hackers getting the data. In addition to that, users are not able to access the servers that have their stored data. Lastly, if the storage providers close up shop, it will be very hard to retrieve a company’s data. Whatever decision we make must ensure that it meets the companies and consumer needs