If we analyze the Cloud technology intelligently, we will see that most people separate the cloud computing model into two distinct set:
On the basis of deployment Model: refers to the management of the cloud’s infrastructure. Cloud hosting deployment model designates the exact category of the cloud environment, its size and accessing mechanism. It also tells the nature and purpose of the cloud.
There are three types of cloud model –
- Public Cloud
- Private Cloud
- Hybrid Cloud
- Community Cloud.
On the basis of Service model: Cloud computing is a broad term which holds a more extensive range of services. It is composed of a particular type of services; cloud computing platform allows its users to access
There are three types of cloud model –
- Infrastructure-as-a-Service (IaaS),
- Platform-as-a-Service (PaaS) and
- Software-as-a-Service (SaaS).
Public cloud allows the accessibility of systems and services easily to general public. When a cloud is available to the general public on a pay-per-use basis, that cloud is called a ‘Public Cloud’.
The customer has no visibility over the location of the cloud computing infrastructure. It is based on the standard cloud computing model.
Examples of public cloud are Amazon EC2, Windows Azure service platform, IBM’s Blue cloud, Microsoft, Google, Rack-space etc.
Advantages of Public Cloud Model
1) Low Cost:-Public cloud is having low cost as compared to private or hybrid cloud, because it shares same resources with large number of consumer.
2) Reliable:-Public cloud provides large number of resources from different locations, if any of the resource fail, public cloud can employ another one.
3) Flexible:-It is very easy to integrate public cloud with private cloud and hence it gives flexible approach to consumers.
4) Location Independent:-It ensures the independency of location, because public cloud services are delivered through Internet.
5) High Scalability:-Cloud resources are available as per the demand from the pool of resources that means they can be scaled up or down according to the requirement.
Disadvantages of Public Cloud Model
1) Low security:-In public cloud model, data is present off-site and resources are shared publicly. Hence it does not ensure the high level security.
2) Less customizable:-It is less customizable than private cloud.
The Private cloud allows the accessibility of systems and services within the organization. Private cloud is operated only within a particular organization.
But it will be managed internally or by third party.
The internal data centers of business organizations which are not made available to the general public are termed as a private cloud. As the name suggests, the private cloud is dedicated to the customer itself. These are more secured as compared to public clouds.
It uses the technology of virtualization.
A private cloud is hosted on the company’s own servers. Example of private cloud technology is Eucalyptus and VMware.
Advantages of Private Cloud Model:-
1) High security and privacy:-Private cloud resources are shared from distinct pool of resources and hence highly secured.
2) More Control:-Private clouds have more control on its resources and hardware than public cloud because it is accessed only within the boundary of an organization.
Disadvantages of Private Cloud Model:-
1) Restriction:-Private cloud is only accessible locally and it is very difficult to deploy globally.
2) More Cost:-Private cloud is having more cost than public clouds.
3) Inflexible price:-In order to fulfill demands, purchasing new hardware is very costly.
4) Less Scalability:-Private clouds are scaled only within capacity of internal hosted resources.
A combination of private and public cloud is called a hybrid cloud. Companies use their own infrastructure for normal usage and hire the cloud at events of heavy network traffic or high data load.
Non-critical activities are performed by public cloud while critical activities are performed by private cloud.
Advantages of Hybrid Cloud Model:-
1) Scalable:-It provides both the features of public and private cloud scalability.
2) Flexible and secure:-It provides secure resources because of private cloud and scalable resources because of public cloud.
3) Cost effective:-It is having less cost as compared to private cloud.
Disadvantages of Hybrid Cloud Model:-
1) Networking issues:-Networking becomes complex because of private and public cloud.
2) Security Compliance:-It is necessary to ensure that cloud services are compliant with the security policies of an organization.
A community cloud is a cloud service model that provides a cloud computing solution to a limited number of individuals or organizations that is governed, managed and secured commonly by all the participating organizations or a third party managed service provider.
The cloud service shares among various organizations and companies which belong to the same community with the common concerns. This can manage either by the third party or internally. Example- Salesforce.com
Or Community Cloud is another type of cloud computing in which the setup of the cloud is shared manually among different organizations that belong to the same community or area.
Example of such a community is where organizations/firms are there along with the financial institutions/banks. A multi-tenant setup developed using cloud among different organizations that belong to a particular community or group having similar computing concern.
Advantages of Community Cloud
- Cost effective:-Community cloud provides same advantage as that of private cloud at low cost.
- Sharing among organization:-Community cloud offers an infrastructure to share cloud resources and competences among several organization.
- Security:-Community cloud is more secure than the public cloud.
Disadvantages of Community Cloud
- Not the right choice for every organization.
- Slow adoption date.