Public vs. Private vs. Hybrid Cloud

Cloud Computing
Cloud Computing enables organizations to leverage scalability, flexibility and agility without significantly increasing IT spending. One of the important characteristics of cloud computing is that resources are self-service manner. Because of being self-service uniform resources are available in uniform manner. These resources can vary in Infrastructure, Platform and Software but important is users get what they need, how much they need and they pay for what they used.

Cloud Services are available in following options:

• Public Cloud
• Private Cloud
• Hybrid Cloud

Public Cloud
A public cloud service is provided “as a service” over the Internet and the customer’s infrastructure or applications are hosted by a cloud service provider at their data centers. The customer has no visibility and control over where the cloud services are being hosted. The data center is shared between many organizations, but each organization’s data & application usage is logically segregated and authorized users of that organization can access their data.

Public cloud can be used when-

• You want to reduce time to market and increased flexibility.
• You don’t want to invest upfront and quickly want to develop, test and deploy the application.
• You have SaaS (Software as a Service) applications from a vendor who has a well-implemented security strategy.
• Your application has incremental or sudden up and down in terms of load.
• You want to leverage ad-hoc services and resources provided by public cloud providers.

Following are major concerns while choosing public cloud-

• Security and reliability
• Vendor lock-in

Private Cloud
A private cloud, also called internal cloud is hosted on private platform in customer’s data center. It is dedicated to a particular enterprise and is not shared with other organization.
Virtualization is the key technology which helps in setting up private cloud by leveraging their existing infrastructure and customer does not need to purchase additional equipment similar to a public cloud. Private cloud offers customers more control over the infrastructure, but at the same time also offers on-demand capability where more services can be added quickly as needed.

Private cloud is a suitable option when –

• You want to control and manage the data and application yourself and don’t want to let you data resides outside your organization.
• Nature of application and business must conform to strict security and data privacy issues. Like financial or healthcare industry products which needs to follow certain compliances/laws.

Following are major concerns while choosing private cloud-

• Upfront investment on Infrastructure
• On-going maintenance
• Capacity Limitation

Hybrid Cloud
As the name suggest, a hybrid cloud comprises both private and public cloud services. In this case some of the services run on public cloud like web application and some reside on private cloud like data and services.

Hybrid cloud is a suitable option when –

• You are concern about security and don’t want to host data publically. So data services can be hosted on private cloud whereas some of public facing applications can reside on public cloud.
• Your application and services are tailed for different vertical markets. In this case data can be securely kept in public cloud and application dealing with customers can be hosted on public cloud.
• You want to distribute workload and keep your application up and running at both public and private cloud.
•  Developing large e-commerce application where high availability is required with security in keeping personal and credit card information of customers.

Following are major concerns while choosing hybrid cloud-

• Complexity in managing both public and private cloud services
• Synchronizing data and application when shared across public and private cloud.
• Keeping track of multiple different security platforms and ensure that all aspects of your business can communicate with each other.
• Privacy and security are still a concern. Complications can also arise due to a lack of cloud standards, data availability and data ownership.