What are clouds and what are they
New words, especially fashionable ones, often have different meanings for different people. This complicates the communication and complicates the discussion of the subject. These new buzzwords include words related to clouds, computer, public, private , hybrid, etc.
There are many reasons for the semantic confusion: new, rapidly developing technologies; multiple traced translation from English; lexical “research” of marketers … However, despite this, it is highly desirable to strive to ensure that the term system in any area of activity becomes more logical, unambiguous, not contradictory.
What is a cloud?
Cloud is a virtual environment in which you can run virtual computers (servers) that can be accessed remotely. Physically, it consists of hardware (powerful hardware computers) and virtualization software (hypervisor).
What types of clouds exist?
- Private Cloud is a virtual environment that a particular owner owns and uses for his own needs.
- Public Cloud – this is such a virtual environment, the owner of which provides services to everyone.
- Hybrid Infrastructure – is such a computing system in which the resources of both the private cloud and the public are shared.
Each of these types of clouds has its own characteristics and advantages.
In general, the “cloud” is not a very computer term. They began to use it, because the Internet in the schemes of computer networks and systems was often designated and is indicated by the image of a cloud.
The cloud (Internet) in such schemes plays the role of a communication channel through which users gain access to some computers or the services they provide.
Then, marketers came up with the idea of considering the cloud not only a communication channel, but also computers with services that are accessible via the Internet.
Further, this is what circumstance arose. Computer resources must be not only affordable, but also reliable.
The desired level of reliability can be ensured by the use of specialized equipment (which is usually expensive), its duplication and redundancy. However, the question immediately arises of the effectiveness of the use of this expensive equipment.
The fact is that the actual level of load on computer systems is quite difficult to predict. To avoid overload, computer systems often design with a very large margin of productivity, with an extremely excessive margin. Sometimes the average level of actual server load does not exceed 20%.
A modern way to increase the efficiency of use of computer equipment is its virtualization.
Historically, operating systems have been quite closely associated with the hardware of computers, that is, on each new computer, first of all, it was necessary to install a certain operating system. Then came the technology of software emulation of the hardware of the computer, which provided a layer between the hardware and the operating system.
This layer made it possible to transfer the operating system from one physical computer to another without reinstalling it. The main condition for such a transfer is the presence on the other computer of the same or compatible “layer”.
However, the “layer” allows not only transferring the operating system, but also placing several copies of operating systems (virtual machines).
This opens up new possibilities. It is known that replacing one large machine in a certain information system with several small computers of the same type can increase the reliability or performance of this system as a whole.
Now we come to a more precise definition of the term “cloud”.
The cloud is a place on the Internet where users are provided with the computing resources of virtual computers. This location is determined by the domain name or IP address.
It is obvious that communication with virtual computers is also carried out via the Internet, in remote access mode.
Thus, the two main distinguishing features of the cloud are:
- use of virtual computers;
- access to them over the Internet.
In the sense of the applied use of a virtual computer, it can be completely perceived as an ordinary “iron” computer, which is installed somewhere far away, and accessed through the network.
When discussing computer clouds, the adjectives “public” or “private” are most often added to them. Technologically, a public cloud is not much different from a private cloud, and vice versa.
The differences between them come down to who owns the infrastructure and who owns it drives.
If the owner of the cloud provides an opportunity for everyone who has paid for the service to receive one or more virtual servers in this cloud, this cloud is public .
A good example of a public cloud is the Logris cloud. We will help you create the right number of virtual servers or virtual networks.
If a certain enterprise, using cloud technologies, built a cloud on its equipment for its internal corporate needs, such a cloud is called private . Private cloud equipment can be located both in the “territory” of its owner, and in the data center (DPC).
Technologically, a private cloud is the same cloud as a public cloud, but used exclusively within one enterprise or organization.
We have a service called “Private Cloud“. The virtual network created by the client as part of this service formally remains part of the public cloud, but it is so well isolated from other parts that it differs little for the third-party user from the described canonical private (corporate) cloud.
Comparison of cloud types
As already noted, the differences between public and private clouds are mainly related to ownership of equipment and areas of responsibility (control). These features are illustrated in the following figures.
A specific information system can be built using elements located both in a private (corporate) cloud and in a public cloud.
The diagram shows one of the many possible options for a hybrid infrastructure. It can be built from several public clouds or from several private clouds, as well as any combination thereof.
The principal sign of a hybrid cloud infrastructure is the use in the same information system of elements located in several clouds (it does not matter, the same or different types).
Often, a hybrid cloud is simply called the simultaneous sharing of different types of clouds.