Three Cloud service Models in a cloud landscape

Three Cloud service Models in a cloud landscape

Infrastructure as a Service (IaaS)

·        This model puts together infrastructures demanded by users—namely servers, storage, networks, and the data center fabric.

·        The user can deploy and run on multiple VMs running the guest OS on specific applications.

·        The user does not manage or control the underlying cloud infrastructure but can specify when to request and release the needed resources.

Platform as a Service (PaaS)

·        This model enables the user to deploy user-built applications onto a virtualized cloud platform. PaaS includes middleware, databases, development tools, and some runtime support such as Web

·        2.0 and Java.

·        The platform includes both hardware and software integrated with specific programming interfaces.

·        The provider supplies the API and software tools (e.g., Java, Python, Web 2.0, .NET). The user is freed from managing the cloud infrastructure.

Software as a Service (SaaS)

·        This refers to browser-initiated application software over thousands of paid cloud customers. The SaaS model applies to business processes, industrial applications, consumer relationship management (CRM), enterprise resources planning (ERP), human resources (HR), and collaborative applications. On the customer side, there is no upfront investment in servers or software licensing. On the provider side, costs are rather low, compared with conventional hosting of user applications.

The Cloud Landscape in an application

Figure 1.4 The Cloud Landscape in an application

Internet clouds offer four deployment modes: private, public, managed, and hybrid. These modes demand different levels of security implications. The different SLAs imply that the security responsibility is shared among all the cloud providers, the cloud resource consumers, and the third-party cloud-enabled software providers. The advantages of cloud computing have been advocated by many IT experts, industry leaders, and computer science researchers.