What is vSphere and vCloud?

Question

1. Can any one help me in understanding vSphere n vCloud director? And difference in both?
2. How to use vCloud's REST URI's in own Java application once it has been installed?
3. Any Java example of using vCloud REST API will be really helpful..!! :-)

Answer 1

The vSphere is the "infrastructural" level of the VMWare virtualization platform. The vSphere is IT controlled layer of virtualization; IT carefully constructs the virtualization of networks, servers, and other network resources through a planned vSphere architecture.

The vSphere is built upon individual ESXi servers. These servers are Type 1 Hypervisor virtualization servers. A type 1 hypervisor is basically a virtualization specific OS. A Type 2 hypervisor is a software that you run on your normal OS to support running virtual machines. In a type 1 hypervisor, like ESXi, the whole OS is geared towards dedicating the resources of the physical server to the single purpose of providing an optimized runtime environment for the execution of virtual machines.

The admin tool for the vSphere used to be called vCenter, which was a client app, but now they are replacing it with the vSphere Web Client. These tools are typically used by IT folks, admins if you will. This is NOT where you go to get the dynamically allocated resources that folks normally think of as the raison d'etre of "the Cloud". The VMWare literature says that the vSphere, while being virtualized, is still the static, cautious realm of IT. It shouldn't attempt to react to the quick turn around provisioning demands, for things like networks and hosts, we expect from a cloud because those quick turnarounds run counter to the cautious edicts of the IT/admin level requirements.

This is where the vCloud Director comes in. This layer sits over the vSphere and provides a more fluid provisioning model. While the vSphere can remain stable and slow to change, thus ensuring levels of performance and security equal to the requirements of enterprise systsm, the vCloud provides a model in which you can instandly deploy networks, servers and other resources. It sits at a layer above the vSphere because it has to be a higher level in order to allow both layers to employe provisioning models that meet the specific requirements of the layer; vSphere requirements focus on traditional IT needs of security and performance while vCloud requirements are all about rapid provisioning. I think the confusion people have comes from not understanding these differeing requirements.

In order to connect to ANY REST API from Java you simply need a programmatic way to make HTTP calls. Low level means are typically built around a client API like HTTP Client. But there are higher level tools like the Spring REST Template. At an even higher level, you could use the Java SDK provided by VMWare; this is a very good option as it allows you to forget about the whole REST aspect and follow a traditionally Java object oriented representation of the vCloud resources. The pdf referenced for the SDK has a Hello World sample in it.