Introduction To Cloud Computing

Client-Server Architecture

The Client-server model depends upon a key interface called web where web refers to a service which is built on top of the internet to allow computers to share and exchange data i.e., pictures files easily and reliably in any form and for that the web is referred to as a client-server communication model because there are computers that ask for data which are called clients and the computer that gives the data, in other words, the computer that serves which is the server.

What is a client?

A client can be a machine or a program. A client is a machine where the user uses to access the web. For example Users, laptop, Users smart phones and computers refer to as clients when the user is searching the web using them.

A client program is a program that allows users to make requests to the web. For example Web browser accessing web page.

Therefore, a client whether it is a Machine or a program is an appliance and a way to make requests through the web.

What is a server?

A server is a computer program ( Remember it is not a device) and high-performance computers are also called servers because they run server programs, Server provides functionality and serves other programs called clients.

A single server can serve multiple clients at the same time, we can run multiple servers on a single machine those are called virtual servers.

What are the types of servers?

There are several types of servers they are

1) WEB Servers ( Apache) : HTTP requests

2) DATABASE Servers ( MY SQL) : DATABASE requests

A server can contain web resources and host web applications store user data and programs etc.

A server is always listening for requests and as soon as it receives one it responds with a message.

Finally, the client-server model is architecture on the web that splits computers into two sections computers that ask for requests are clients, and the computers that serve clients are called servers. This model works through a request-response cycle via HTTP. And it is a one-way model for computers to communicate via the web.

Why Cloud Computing

Cloud Computing is the on-demand delivery of IT resources via the Internet with pay-as-you-go pricing instead of buying fixing and replacing physical data centers and servers where with the help of cloud computing we can access the basic resources like computing power, storage, and databases.

Organizations of every type size and industry are using the cloud for a wide variety of use cases such as data backup, disaster recovery, email, virtual desktops, software development, and testing, Big data analytics, and customer-facing web applications.

For example, Financial services companies are using the cloud to power real-time fraud detection and prevention.

With Cloud computing one’s business can become more agile, reduce cost, instantly scale, and deploy globally in minutes.

Cloud Computing can give access to a broad range of technologies where we can innovate faster from Infrastructure services like compute storage and databases.

With Cloud computing, you can access resources from the cloud in real-time as they are needed.

Basics of Cloud Computing

The cloud computing basics are defined in the form of services where these services play a vital role in the conceptual understanding of cloud computing.

There are three types of services offered by the cloud in general are

1) Infrastructure as a service

2) Platform as a service

3) Software as a service

There are some of the subtopics in these services which are referred to as resources in the cloud which gives us a clear understanding of the cloud those resources are

1) Compute

2) Networking

3) Storage

4) Mobile

5) Databases

6) Web

7) Internet of things

8) Big Data

9) Artificial Intelligence

10) DevOps

And there are so many services that give us a great Idea about the cloud and its services and having the idea about the above services gives us a basic understanding of the cloud concept.

History of Cloud Computing

In the early 1990s Cloud has become the main stay of modern work life and leisure; the origin of the term cloud computing can be traced back to the overlapping of server icons that resembled the cloud-like shape. In early 1996 a great company like Compaq Computers has begun to develop Internal use marketing strategies called cloud services.

The cloud is the metaphor for segments of a network that can be accessed from any number of devices through the internet

Each segment uses the concept of virtualization

In late 2003 a company amazon.com development team in a satellite office in South Africa presented a more innovative approach i.e., what if they can build a system that was made up of largely web-based services and that was fully automated and requires less system maintenance and this idea got implemented in 2006.

In 2008 by capital expenditures by wireless and cable companies leading to increase speed and reliability of networks amazon web services has launched its service cloud like AWS.

Cloud Computing Architecture

There are so many devices that access the internet that can also access the cloud through the internet like computers, laptops, Mobile Phones, etc those devices which have accessed the cloud can also access the resources inside the cloud-like storage, applications, and Infrastructure.

The cloud computing architecture comprises of many cloud components that are loosely coupled ( they are not dependent on one another) We can broadly divide cloud architecture into two types they are :

1) Front end: Refers to the client part of the cloud system consists of interfaces and applications that are required to access the cloud, Example: Web browser.

2) Back end: Refers to the cloud itself it comprises huge data storage, Virtual machines, security mechanism, service, deployment models, servers, etc.

Advantages and Disadvantages

Advantages :

1) Backup and recovery

2) Accessibility

3) Unlimited storage

4) Cost Saving

5) Reliability

Disadvantages :

1) Security

2) Accessibility

3) Downtime

4) Lock-In

Public-Private and Hybrid Cloud

Public cloud: Using public cloud vendors like AWS, Azure, Google cloud expands the sharing and syncing capacities making it accessible and backup of data is simpler.

The cloud computing infrastructure is located on the premises of the company that offers services.

Multi-Tenancy data of many organizations shared in a standard environment.

Anyone can access public cloud services

The data center location is on the internet where services are available.

Private Cloud: Using private cloud fetches hardware as per the requirements of an application.

Private cloud means using a cloud infrastructure only by one customer or organization and it is not shared with others.

Dell is one of the companies that offer private cloud services.

Single-tenancy where the data of the organization is kept in one cloud.

Only organizations can use private cloud services.

Data center location is inside the organization network

Hybrid Cloud: Hybrid cloud manages traffic levels during peak usage periods.

A hybrid cloud uses both public and private clouds based on purpose and requirements.

IBM is one of the hybrid cloud services.

The data stored in the hybrid cloud is multi-tenant and is kept secure with the help of a private cloud.

Anyone can access hybrid cloud services and also the organizations can use private cloud services.

The data center location is inside the organization for private cloud services and anywhere on the internet.

Cloud Service providers

A cloud service provider is a company that offers components of cloud computing as a service typically there are three main services, they are

1) Infrastructure as a service

2) Platform as a service

3) Software as a service

Cloud Services

There are so many cloud vendors that are giving their services in the form of private-public and hybrid clouds and some of the main cloud vendors are AWS, Microsoft Azure, Google Cloud Platform, IBM Cloud, Oracle Cloud, Dell, Nutanix, Salesforce, Cloud sigma.

CIDR

Class less Inter-Domain routing allows internet service providers to reduce wasting of IP address by assigning a company a subset of a network number instead of the entire network

It also reduces the size of Internet routing tables allowing the internet to grow.

It is a convention defined in RFC(Request for comments) that calls for aggregating multiple networks into a single routing entity.

CIDR actually was created to help the scalability of internet routers.

CIDR also helps to reduce the chance that we will run out of IP addresses for new companies connecting to the internet.

Subnetting

A subnet is a group of hosts, all of which have an identical beginning portion of their IP addresses. A subnet differs from a network in that a subnet is a further subdivision of a network, with a longer portion of the addresses being identical.

Subnetting is the process of subdividing networks into smaller subnets.

IP subnetting creates a vastly larger number of smaller groups of IP addresses compared with simply using Class A, Class B, and Class C Conventions.

The Class A, B, and C rules still exist but now a single Class A, B, and C networks are sub divides into too many smaller groups.

Subnetting treats a single division of Single Class A, B, and C network as if it were a network itself.

By doing so a single Class A, B, or C network can be subdivided into too many non-overlapping subnets.