TechnoBuddy: Sure dear Fairies. Cloud Computing is categorized in two kinds pf models 1) Cloud Deployment models and 2) Cloud Service models
Fairies: What is the difference between Cloud Deployment models and Cloud Service models?
TechnoBuddy: A Cloud Deployment model defines the objective of the cloud and location of cloud resources; where they are located. NIST has defined four cloud deployment model: Public cloud, Private cloud, Hybrid cloud, and Community cloud.
TechnoBuddy: Public cloud resources are available for public use and is owned by an cloud service provider. Private cloud infrastructure is for exclusive use of an organization and it is available on premise.
Fairies: Buddy, what is Hybrid cloud and Community cloud?
TechnoBuddy: Hybrid cloud combines two or more types of Cloud deployment models. Community cloud retain unique identities, but are bound together as one unit for providing standardized services to specific set of customers who have similar kind of security or complaince requirements. It serves a common function or purpose in short. Often it is managed by the some organization or a third party
TechnoBuddy: As Cloud Computing has developed, various vendors offer clouds with different services associated with them. Based on this we have the second category called as service model.
TechnoBuddy: There are three types of service models as per NIST definition 1)Infrastructure as a Service (IaaS) 2)Platform as a Service (PaaS) and 3)Software as a Service (SaaS). Now “Anything” as a Service is also a buzz word.
Fairies: What is IaaS, PaaS, and SaaS
TechnoBuddy: TInfrastructure as a Service or IaaS is service offering that comprise of compute, storage and network on demand. Cloud service provider manages all the infrastructure and consumer is responsible for managing upper layers such as runtime environment, OS, etc. Microsoft Azure and AWS are examples of IaaS.
TechnoBuddy: PaaS offers an environment where developers can create and deploy applications. No need to worry about underlying Infrastructure as well as runtime environment. CloudFoundry, CloudBees, MIcrosoft Azure, Google AppEngine are examples of Platform as a Service.
TechnoBuddy: Software as a Service or SaaS is a service offering where the application is provided to the user considering multi tenant scenario. Responsibility of Cloud Service Provider increases while responsibilities of consumer is less compare to PaaS and IaaS. Office 365 and Salesforce are examples of Software as a Service. Cloud service providers resources that are pooled together for better resource utilization. It also provides situation where cloud consumers feel availability of unlimited computing resources on demand and in pay as you go manner. The resources in the cloud are accessible over the network using standard methods.
Fairies: Are there any issues with Cloud computing?
TechnoBuddy: There are number of challenges including data security (CIA-Confidentiality, Integrity, Availability), data lock-in, Legal and regulatory issues, standardization, efficient management of virtualized resource pools, Cloud service provider’s service outage, Control, Governance, and disaster recovery.