Deployment and service model in Cloud Computing
Clouds are primarily platforms that allow execution in various forms.
Depending on the kind of cloud deployment cloud may have limited private computing resources or may have access to large quantities of remotely accessed resources.
Following deployment models represent a number of trade-offs in how customers can control their cost, and the scale, resources, and availability of resources.
• Private cloud: The cloud infrastructure is operated solely for an organization. This type of cloud may be managed by the organization or a third party and may exist on premise or off premise.
• Community cloud: The infrastructure of cloud is shared by several organizations and supports a specific community that has shared concerns [e.g., security requirements, policy, mission, and compliance consideration]. This may be managed by the organizations or a third party and may exist on premise or off premise.
• Public cloud: The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
• On-site private cloud: The security parameter for this deployment model extends around both the subscriber’s on-site resources and the private cloud’s resources. The private cloud may be centralized at a single subscriber site or may be distributed over several subscriber sites. The subscriber implements the security parameter which will not guarantee control over the private cloud’s resources but will enable the subscriber to exercise control over resources entrusted to the on-site private cloud.
Hybrid cloud: Infrastructure of cloud is a composition of two or more clouds (private, community, or public) that remain unique entities but that are bound together by standardized or proprietary technology enabling data and application portability.
The following service models have different strengths and are suitable for different customers and business objectives. In general, interoperability and portability of customer’s workloads are more achievable in the Infrastructure as a Service (IaaS) service model because the building blocks of this service are relatively well-defined.
• Cloud Software as a Service (SaaS).
The subscriber uses the provider’s applications running on a cloud infrastructure. Applications are accessible from various client devices through a thin client interface such as a Web browser.Consumer does not manage or control the underlying cloud infrastructure, including operating systems, storage, network, servers, or individual application capabilities. It may be possible for the subscriber to specify application configuration settings.
•Cloud Platform as a Service (PaaS).
This service allows the subscriber to deploy onto the cloud infrastructure applications that the subscriber created or acquired using programming languages and tools supported by the provider. Consumers does not manage or control the underlying cloud infrastructure including network, servers, operating systems or storage but has control over the deployed applications and possibly application hosting environment configurations.
•Cloud Infrastructure as a Service (IaaS).
This service enables the subscriber to use storage, networks, processing, and other fundamental computing resources and to deploy and run other software, including applications and operating systems. Consumers does not manage or control the underlying cloud infrastructure but has control over operating systems, deployed applications, storage, and possibly limited control of select networking components , such as host firewalls.