Key Enabling Technologies for Virtual Private Clouds

Virtual private cloud is an configurable pool of shared resources on demand. Concept of VPC is emerged recently for a single organization. And it may build from physical resources of organization, external service provider or combination of both. The VPC concept is both transformational and fundamental. The concept of VPC is fundamental and transformational.

VPC Processes abstraction of public resources combined with internal resources which provide equivalent functionality and give surety that physical resources are operated for single organization. And public resources can be shared with other organizations. It also provides a path for organization to incorporate cloud computing into IT Infrastructure.

Virtual Private Clouds

By the definition of cloud given in Mell and Grance (2009) we extract three key questions about deployment of cloud which are:

1. Where is the infrastructure?
2. Who runs the infrastructure?
3. Who uses the cloud infrastructure?

First two questions are about implementation that may be applied on more than one deployment model. And the distimction of public, private, community and hybrid cloud is answer to last question.

VPC is built from the hybrid of an external public cloud and an internal private cloud Virtual Data Centers In conventional IT, data centers provide a convenient way of organizing resources into locally connected pools.

The locality provides an opportunity for common physical oversight and improved network performance among resources within the data center. In effect, a data center can be viewed as a local container of IT resources that can be managed together from a resource, security, and/or information perspective. For practical reasons, a VDC will typically be implemented based on a single, underlying physical data center; the apparent local connectivity would otherwise be difficult to achieve.

The limitation is only in one direction, of course: A given physical data center can host more than one VDC. Furthermore, a data center operated by a public cloud provider may offer VDCs to multiple organizations, or henceforth, tenants, so the underlying computing environment is multi-tenant.

Virtual Applications

Information based processes in conventional IT are realized by various applications involving interactions among collections of resources. The resources supporting a given application may run in a single data center or across multiple data centers depending on application requirements. Just as a VDC can show a data center in a more ideal form, a virtual application can present the appearance of an application as it ideally should be.

Today, security, resource management, and information management are typically enforced by the operating system and application stack, which makes them complex and expensive to implement and maintain. With the simplified, unified management provided by the virtual application abstraction and encapsulation of application components in virtual machine containers, the virtual application container becomes a new control point for consistent application management. Instead of orchestrating each resource individually, an organization can operate on the full set in concert, achieving the equivalent of "One click" provisioning, power on, snapshot, backup, and so on. Virtual applications run across one or more private data centers connected by virtual private networks

In a conventional data center, that application might be implemented as the combination of resources starting with a web server and a database. A firewall would be added to meet the security objectives, and a load-balancer to assign transactions to additional web servers as needed to meet the performance objectives. To address the business continuity objectives, a second instance of these components might be placed in another data center, coordinated with the first through a business continuity manager. Deploying an application in a VPC as just described has some advantages, such as dynamic allocation of resources and economies of scale.

Cloud computing environments can improve this situation by organizing components and capabilities into searchable lists of virtual applications and resources that can readily be deployed. Instead of each application contributing its own load-balancer, the VPC would offer one itself for use by multiple applications. Once an application designer knows that load balancing will be available, he or she no longer needs to specify a virtual application as a combination of, say, two web servers and a load-balancer.

Load balancer: load balancer is an instance of general pattern Applications are designed as a combination of functionality and qualities relating to service-level agreements (SLA) These qualities are called “illities”. In Given VPC facing a problem recognizing the “ilities” and therefore, managing them or optimizing their delivery and it is difficult to optimize object code without the original source. Therefore, the preferred model for application deployment in a Virtual Private Cloud is for the computing environment to add “ilities” as part of deployment.

Policy Compliance

In whatever computing environment an organization chooses to deploy an application, the organization will need some evidence that the application is running as intended. This evidence serves both the organization's own assurances and those of auditors or customers. Policy objectives are particularly difficult to achieve in a multi-application setting because of the potential for resource contention. A physical computing resource may reliably meet the computational performance objectives for the one application it supports, but when that resource interacts with another resource, the presence of network traffic from other applications may make the communication performance unpredictable. There may also be opportunities for different applications, by design, to operate in a complementary fashion that reduces the contention.

Service Management Integration: Service management integration is a special case of the broader technology of information integration, which is concerned with translating of federating general information from multiple domains.

The special case of VPCs is concerned in particular with federating three things: the underlying infrastructure into one, virtual computing environment, identities interacting with the resources in the environment, and information about the resources.