Interview Questions on Cloud Computig

What is Cloud Computing?
Cloud computing means storing and accessing data and programs over the Internet instead of your computer’s hard drive.
We can also define like it is a pool of highly scalable, abstracted and managed compute infrastructure capable of hosting end customer application & billed by consumption.

What are the characteristics of Cloud Computing?
On-demand, Scalable, Multi-tenant, Reliability and Utility based subscription.

What are the different types of cloud computing models?
1. Software as a service (SAAS)
2. Platform as a service (PAAS)
3. Infrastructure as a service (IAAS)

What is Software as a Service (SAAS)?
In SAAS, a complete application is offered to the customer as a service on demand. Highly scalable internet on based applications are hosted on the cloud & offered as a service to the end user.
Examples: Salesforce.com, Google docs.

What is Platform as a service?
In PAAS, development environment is encapsulated & offered as a service. By using this we can develop, build & test our own applications.
Examples: Force.com, Google App Engine.

What is Infrastructure as a service (IAAS)?
This model is pay per use model, services like storage, database management & compute capabilities are offered on demand.
Examples: Amazon Web services.

What are the different types of clouds?

1. Public Cloud
2. Private Cloud
3. Hybrid Cloud

What is public cloud?
A service provider makes resources, such as applications and storage, available to the general public over the Internet. Public cloud services may be free or offered on a pay-per-usage model.

What is Private cloud?
It is designed to offer the same features and benefits of public cloud systems, but removes a number of objections to the cloud computing model including control over enterprise and customer data, worries about security, and issues connected to regulatory compliance.

What is hybrid cloud?
It is a composition of at least one private cloud and at least one public cloud. A hybrid cloud is typically offered in one of two ways: a vendor has a private cloud and forms a partnership with a public cloud provider, or a public cloud provider forms a partnership with a vendor that provides private cloud platforms.

list few Cloud provider companies?
IAAS Providers:
– Amazon Web Services (AWS)
– AT & T
– Cisco Systems
– EMC
– GoGrid
– Hewlett-Packard
– IBM
– Microsoft

PAAS Providers:
– CloudBees
– Engine Yard
– GigaSpaces
– Red Hat
– Google App Engine
– Force.companies

SAAS Providers:
– Salesforce.com
– Google
– Oracle
– SAP
– Workday