Cloud Computing – Types of Cloud

Cloud computing is usually described in one of two ways. Either based on the cloud location, or on the service that the cloud is offering.

Based on a cloud location, we can classify cloud as:

1. public,
2. private,
3. hybrid
4. community cloud

Based on a service that the cloud is offering, we are speaking of either:

1. IaaS (Infrastructure-as-a-Service)
2. PaaS (Platform-as-a-Service)
3. SaaS (Software-as-a-Service)
4. or, Storage, Database, Information, Process, Application, Integration, Security, Management, Testing-as-a-service

Where Do I Pull the Switch: Cloud Location

public cloud mean that the whole computing infrastructure is located on the premises of a cloud computing company that offers the cloud service. The location remains, thus, separate from the customer and he has no physical control over the infrastructure.

As public clouds use shared resources, they do excel mostly in performance, but are also most vulnerable to various attacks.

Advantages

• Virtually unlimited resources – You can instantly provision virtually unlimited amount of resources
• Scalability & Elasticity – You can scale up or down your resources to meet demand peaks and lows, and you pay only for what you use
• Pay as you go – No Capex, you pay a monthly bill

Limitations

• Lack of Perceived Amortization Benefits on Investment – I have come across, large enterprises which shy away from Public Cloud as it is perceived that the amortization benefits on Capital Investments are higher than the Operational Expense benefits incurred on Cloud.
• Compliance – Public Cloud providers may not be following all the regulatory compliance required by an organization.

If you are a startup or a small enterprise, Public Cloud is the best option to adapt Cloud Computing. You get access to the best in class resources on a pay as you go basis without any initial investments. Also you save on the amount to be spent on maintenance of the resources.

Private cloud means using a cloud infrastructure (network) solely by one customer/organization. It is not shared with others, yet it is remotely located. If the cloud is externally hosted. The companies have an option of choosing an on-premise private cloud as well, which is more expensive, but they do have a physical control over the infrastructure.

The security and control level is highest while using a private network. Yet, the cost reduction can be minimal, if the company needs to invest in an on-premise cloud infrastructure.

Advantages

• Security – There is a sense of security among organizations as the data resides on premise
• Compliance – Enterprises can comply to the compliance standards required for their industries and follow the required corporate governance structure for their organizations

Limitations

• Costs – Organizations need to own the hardware, storage and networking resources upfront and also spend on the maintenance of all the resources
• Complexity – Private Clouds are complex to deploy and maintain because of the complex virtualization of the hardware resources

If you are a large enterprise, it makes sense to capitalize on your existing investments which are already made on hardware infrastructure and have a private cloud deployment on top of it.

Hybrid cloud means, using both private and public clouds, depending on their purpose.

Advantages

• Flexibility – Organizations can make use of various Public and Private Clouds to utilize the advantages of both the deployment models.
• Cloud Bursting – You can run an application on private cloud and burst it to public cloud to meet demand peaks

Limitations

• Complexity – To deploy a hybrid model is quite complex because of the varying standards of each provider

Large enterprises are adopting this model and using it in multiple ways like Storage & Archiving, Cloud bursting, development and test on Public Cloud & Production on Private Cloud among others.

Community cloud implies an infrastructure that is shared between organizations, usually with the shared data and data management concerns. For example, a community cloud can belong to a government of a single country. Community clouds can be located both on and off the premises.

What Can I Do With It: Cloud Service

What do we mean by cloud computing services? Cloud computing comes in three basic flavors: software as a service (SaaS), platform as a service (PaaS), and infrastructure as a service (IaaS).

Software as a Service (SaaS)

SaaS is far and away the most common model of cloud service: Companies buy access to an application but have no responsibility for (and no control over) its implementation. More than 60% of companies that Nemertes works with already use at least one (and often several ) applications that they get via SaaS, ranging from horizontally useful tools such as customer relationship management (as with Salesforce.com) to more vertically specific tools for such tasks as insurance claims adjustment, classroom scheduling and medical billing management.

Platform as a Service (PaaS)

PaaS involves providing a platform on which a customer can run its own applications. For example, a small company might have a Java application to which it has trouble providing enough resources during holiday peak loads. The company might go to a platform provider, such as Akamai, to run the system on its Java application server framework. Microsoft, Force.com and Google also provide platforms on which customers can run applications.

Infrastructure as a Service (Iaas)

IaaS allows an organization to run entire data center application stacks, from the operating system up to the application, on a service provider's infrastructure. Amazon's Elastic Compute Cloud is perhaps the most famous public cloud infrastructure available.