Cloud Computing Overview
In any discussion of cloud computing, it’s important to start from the beginning and understand the power that drives the changes and technological advancements in data centers and the technology as a whole.
The ancient Greek philosopher Heraclitus had the following to say: “Everything changes and nothing remains still.” Change is the only constant in human life. And, as the world changes, so do the requirements for companies to develop their business, for organizations to continue their operations, and so on. This leads to the services offered by different entities that address the need to continuously change and evolve, stay up to date, and satisfy the needs of businesses or organizations.
So how does this change affect data centers, and what is the link to cloud computing?
The services are provided by applications. The applications run on top of servers, virtualized or bare metal, which require operating systems and additional software to create the environment for the applications. The applications have to be accessible by the end users and administrators, and at the same time the applications have to be capable of communicating with the databases, which are other applications running on servers, with operating systems, and responsible for the data being organized and stored within a specific structure. Therefore, there is the need for communication, which is provided by the networks in the data centers. The Cisco ACI is one such example, and it’s covered in Chapter 8, “Describing Cisco ACI,” and Chapter 9, “Operating ACI,” of this book. All the data needs to be stored somewhere, and this is where the storage infrastructures and the storage systems are involved. Also, all these components need to be secured and monitored because they are the components that build the data center. Said in a different way, these components, working together, provide the needed computing resources for the applications to run.
The aforementioned leads us to the conclusion that what will change, and what is changing, is how the computing resources provided by the data centers are utilized, managed, and consumed! And this is the next step in the evolution of the data centers, and it is known as “cloud computing.” Cloud computing is an approach in which the computing resources are utilized in a way where their consumption can be measured, automated, accessible, and managed.
One especially important clarification needs to be made: what are the “computing resources”? The cloud resources are not only the resources of the server or virtual machine required to run the applications. They also include the resources we need for communication, as the network and security devices, being physical or virtual, also use CPUs, memory, operating systems, and so on. The storage infrastructures and systems also need CPUs, memory, and operating systems. Therefore, the term “computing resources,” from the perspective of defining and describing cloud computing, includes any and all hardware and software resources in the data center.
Three important documents were created by the computer security division at the Information Technology Laboratory at NIST. These documents provided the first definition of “cloud computing” and its components:
- NIST Special Publication 800-145: The NIST Definition of Cloud Computing (September, 2011)
- NIST Special Publication 800-144: Guidelines on Security and Privacy in Public Cloud Computing (December, 2011)
- NIST Special Publication 800-146: Cloud Computing Synopsis and Recommendations (May, 2012)