Cloud Computing is nothing but using and accessing applications through internet. In addition to configuration and manipulation of applications we can also store data online. Usually in cloud computing you do not need to install any software for any application to run or work in your PC, this is what makes a difference which avoids platform dependency issues. This is how Cloud computing is making applications mobile and collaborative.
Behind Cloud Computing platform there are 4 technologies working which makes Cloud Computing flexible and reliable. The Cloud Computing technologies are :
1. Virtualization :Virtualization is a technique where in an instance of application that is present physically is allowed to be shared with many computers and organizations. This is done by allocating a name to that physical resource and when requested, it is directed using a pointer. By this the customers can use as if they own the instance without actually having it physically.
2. Service-Oriented Architecture (SOA) : SOA is a technique that allows customers to use applications as a service to access other applications irrespective of technology, product etc. Due to this functionality the data exchange between different applications is possible without any additional programming and installation.
3. Grid Computing : This is a technique where computers from different locations in the world work together for a common objective. Grid Computing makes complex tasks simple and into small pieces,these pieces are distributed among CPUs present in the grid.
4. Utility Computing : This techniques is a kind of pay and use which is more applicable in managing IT services. It provides the service to the customers and charge them according to the usage instead of flat price.
Cloud Computing Architecture
The basic cloud computing architecture is divided into two main parts.
1.Front End : The front end is the client part. It consists of interfaces and applications which are necessary to access other applications. The front end is connected to back end via internet. For example web browsers are front ends.
2.Back End : It is the cloud by itself containing huge data storage, security, deployment models, service, servers, cloud infrastructure,management etc.
The cloud infrastructure comprises of management software, deployment software, network, servers, storage and hypervisor.
- Management software : It maintains and configures the infrastructure.
- Hypervisor : It is a low level program that allows physical resources to share among customers. This acts as a Virtual Machine Manager.
- Network : It helps the cloud services in connecting through internet and also the customers can change network route and protocol as per their requirement.
- Server : It helps in computation and also provides services like resource allocation and deallocation, monitoring and many more.
- Storage : Cloud computing makes storage very reliable as it uses file distributed system. In this system if the data couldn’t be fetched from one file then it fetches from other files.
- Deployment Software : It helps in deploying and integrating applications on the cloud.
There are four kinds of deployment models
Public Cloud Model : In this model all (general public) can access applications and services. Many providers exist, in which some of them are Google, Amazon, Microsoft etc.
- It is cost effective
- It is flexible
- It is reliable
- It is location Independent
- It is highly scalable
- It has low security as it is available in public and may be attacked by virus or DDoS.
- It is less customizable than other clouds.
Private Cloud Model : In this model only people of particular organization can access the applications and services. It can also be managed internally or by a third party.
- As it is accessible within an organisation it has high security and privacy.
- You can have more control over the cloud
- Restricted area
- High pricing
- Limited scalability
Hybrid Cloud Model : This model is the combination of public and private Cloud models. In this you can perform non critical activities using public cloud and critical activities using private cloud.
- Cost efficient
- There may be security issues.
- Infrastructural Dependency
Community Cloud Model : In this model a group of organizations can use the same cloud ie., here the infrastructure is shared by a group of organizations and can be maintained internally or with the help of third party.
- Cost effective
Cloud Service Models
There are 3 basic service models
Infrastructure as a Service (IaaS) Model : This model offers access to physical resources like physical and virtual machines, data storage. Virtual Machines are pre installed as an operating system and they allow to store a specific data in different locations and also computing resources can be easily scaled up and down. It offers disk storage, local area network , load balancers, IP addresses, software bundles etc. This model also allows the cloud provider to locate infrastructure over the internet. IaaS helps in controlling the computing resources via administrative access to virtual machines. There are also some issues along with the benefits and the issues are compatibility with legacy security vulnerabilities, virtual machine sprawl etc.
Platform as a Service (PaaS) Model : This model acts as a run time environment and allow to develop and deploy tools required for the applications. It has a special feature that helps non developers to create web applications. This also offers API and development tools required to develop an application. The benefits of this model are low cost of ownership and scalable solutions. But the disadvantage is, in PaaS the consumer’s browser has to maintain reliable and secure connections to the provider systems. There is also a lack of probability between PaaS clouds.
Software as a Service (SaaS) Model : In this model a software is deployed on hosted service and is accessible through internet. It allows to provide software application to the users. Billing and Invoicing System,customer relationship management (CRM) applications, Help Desk Applications are some of SaaS applications. The software’s license is available based on usage or subscription. They are cost effective and requires less maintenance . In this multiple users can share an instance and is not required to code functionality of each user. Scalability, efficiency, performance are the benefits of SaaS. The issues with this model are Lack of portability between SaaS clouds and browser based risks.
The cloud storage helps in saving data offline, which is maintained by a third party. The storage devices are classified into two:
- Block Storage Devices : Raw storage is offered to the clients and allows to create volumes using raw storage.
- File Storage Devices : In this storage is in the form of NAS(Network Attached Storage). Here clients are offered the storage in the form of files.
What is Cloud Hosting?
Cloud computing offers hosting services called cloud hosting. In cloud hosting websites are hosted on virtual server and when the information is required, the files are pulled from a network of physical web server and depending on the service requirement, files are fetched. There is also a facility in cloud hosting that you can pay based on your usage and avoid payment for unused.
How is Cloud Hosting different from Traditional Hosting?
The traditional hosting normally are four different types of hosting services, they are shared hosting,VPS hosting, dedicated hosting and grid hosting. When comparing these hosting services with cloud hosting you will know the difference between cloud and traditional hosting.
- When comparing cloud hosting with shared hosting we find that in shared hosting the probability of down time is more compared to cloud hosting.
- When comparing cloud hosting with VPS hosting we find that VPS servers are less efficient that cloud servers as it fetches files from one server only where as cloud fetches files from multiple servers when required.
- When comparing cloud hosting with dedicated hosting we find that in dedicated hosting, servers don’t run on full capacity and are very expensive compared to cloud hosting.
- When comparing cloud hosting with grid hosting we find that grid hosting is same as cloud hosting but the difference lies in the processing procedure of completing a huge task.
- As you don’t have to maintain separate physical servers for every application and service, it is cost effective.
- The data storage is almost unlimited.
- As your data will be stored in the cloud it is easy to recover, than when stored in any other device.
- As software will be installed automatically when needed you don’t have install manually or upgrade it.
- It is easy to access as you can get your information from anywhere in the world, if once registered.
- As it is a new upcoming technology there might be some technical issues, in which some of them can be solved and some cannot.
- Security is major problem.
- It may be prone to attacks as files will be fetched from different servers. If one server is attacked automatically whole network is attacked.
Like every technology has pros and cons, cloud hosting too has. It depends on your requirements and budget, based on which you have to choose the right hosting for your website as choosing right hosting is very important and difficult too because it really matters for your business.