Cloud Computing – A Five Layer Model
When someone talks about Cloud Computing, what exactly are they talking about?
As more functionality moves to the internet cloud every provider and user is developing their own definition. Industry experts and researchers are struggling to formulate a standard set of terms to describe all the different functions. This graphic developed by Lamia Youseff, University of California, Santa Barbara and Maria Butrico, Dilma Da Silva, IBM T.J. Watson Research Center depicts as five layers, with three constituents to the cloud infrastructure layer. The figure represents the inter-dependency between the different layers in the cloud.
They define the five levels as follows:
A. Cloud Application Layer –The most visible layer to the end-users of the cloud. Normally, the users access the services provided by this layer through web-portals, and are sometimes required to pay fees to use them.
B. Cloud Software Environment Layer – The second layer in our proposed cloud ontology is the cloud software environment layer (also dubbed the software platform layer). The users of this layer are cloud applications’ developers, implementing their applications for and deploying them on the cloud.
C. Cloud Software Infrastructure Layer – The cloud software infrastructure layer provides fundamental resources to other higher-level layers. Cloud services offered in this layer can be categorized into: computational resources, data storage, and communications.
D. Software Kernel – This cloud layer provides the basic software management for the physical servers that compose the cloud. Software kernels at this level can be implemented as an OS kernel, hypervisor, and virtual machine monitor and/or clustering middleware.
E. Hardware and Firmware – The bottom layer of the cloud stack in our proposed ontology is the actual physical hardware and switches that form the backbone of the cloud. In this regard, users of this layer of the cloud are normally big enterprises with huge IT requirements in need of subleasing Hardware as a Service (HaaS).
Are these really five different levels. Is there much difference between Infrastructure and Hardware? Or are the two merging as the technology continues to evolve?