Server equipment for duplication. What is server equipment? What is the mail server

The server is a kind of program, a device or software and hardware complex that implements some services. In turn, the service is a service that performs certain actions requested by the client. Let's take a closer look at the server.

Customer-server components

Let's see what the server itself is and without which external components He can't do. First, the server loses its meaning in the absence of customers. The principle of server operation is to implement customer needs. The client forms the requirements for the server and takes on some share of his work. Therefore, it is not just about the server more often, but about the system client-server system. The client makes up requests to the server, through which he sees its will. Therefore, the next, second component of the system will be the formal language in which these requests are compiled. These languages \u200b\u200bare a great set and selection of this or that directly depends on the server. Requests to the server should somehow deliver. The third element is the client's communication channel and the server to be transmitted. It is most often either the local networkor Internet or local connections of one machine. The Server request has come to somehow accept and recognize. The receiving device is the so-called external interface, represents several ports that the server continuously (or not continuously) listens. Accepted requests are sent to software Servers, where and processed according to how the server is programmed. And depending on the received request, one or another service with those or other initial data is launched. Services will be the last component of the system. After the service is completed, the execution result is sent to the client on the same communication channel. Or, if the service is interactive, then in the process of its operation there will be an intensive exchange of data on the Channel "Client-server".

What is the server for what

Now the main purpose of client-server systems is to move the load from the client machines to the server. That is why the computational power of the usual server for a couple of orders is higher than the ordinary home Computer. But sometimes this organization of the system's work gives all the load on customers, and the server serves to organize their work and interaction. Or strictly on the contrary, the server performs all calculations, and customers serve only to issue information to the user. As you can see ways to use a client-server model mass.

Pros and cons model

Pros are obvious - the principle of operation of the server itself provides the convenience of working with the system, ease of control of it, the correct distribution of the load on the machine. A minus is the language of requests and associated components. If the user accidentally or deliberately refers to the server an incorrectly formulated query, then if such an error has not been provided by the programmer, the system will fail. The knowledgeable people make up knowingly incorrect requests so that the system designed to issue the client to the client, brought the attacker, for example, credit card data of all users (if, of course, the same server is responsible for the data of the maps and the weather forecast). And the happy attacker first goes and lists all the money of all users of the service, and then long and thoughtfully runs away from the management of "K", which is investigating this crime.

Safety

The client-server model of the organization's work organization is very convenient in programming, management and work thing. But that such a system can be used, each component of the working circuit must be protected from both intruders and users who do not know how the server works, but the all the buttons to which will be able to reach in an arbitrary sequence. In order to store and process important data in the system, such as payment card information, system, system information security Servers must meet with a certain law of requirements.

Let's figure out what the server computer differs from the usual wall-personal and which there may be practical tasks for buying a server computer for home.

Before a few theory. What is the meaning of the term "server computer" in itself, is he "server"? Latin root "Serv" means "servant", and also acts as a key part in derivative words. "Server" needs to be understood as a computer whose task is to provide a set of services to the user who has been given to the user, while automatic mode, without the participation of permanent control by the human operator.

You can imagine a student hostel, where guys and girls from different floors and rooms are divided into each other files, Internet access or run games with joint participation - on completely ordinary computers and laptops. Some network settings - And in the exact location there is a real server computer. In the simplest version, the server can actually actually play old computer - Set the settings, stick the wires and shake under the table.

But what is suitable for several units or even dozens of people will not work completely on a more large-scale level. Three main properties are distinguished by server computers from ordinary:

1. The server must handle the requests of all users with the maximum speed level.
2. The server must work continuously, even regular reboots - extremely undesirable. On the network slang, the continuity of the server is called "aptime".
3. Especially undesirable to disable the entire server if you need to replace any component. The ability to not turn off the whole when replacing the private can be called a "hot connection".

How to understand this in practice? We take access to the Internet - the provider provides a connection with a given speed, keeps accounting traffic and payments. All this is done through the operation of server computers - and even in the simplest case we are talking about thousands of users. And all these users must calmly receive a paid service set, and not be angry due to delays or lack of communication.

The provider's server computer provided a person access to the Internet, and from what is the last? Simplified - from sites. And this is again servers, only not communication providers, and hosting providers - services for the creation, storage and provision of sites. In some cases, many small sites will be physically on one machine, in others - a powerful dedicated server will work in the interests of only one popular site.

Servers are not necessarily connected to the global network. It is possible to mention scientific calculations where gigantic computing resources are needed, servers are popular and on a variety of enterprises - from plants to stores, which makes it possible to effectively record and control, processing many statistical queries. No ordinary personal computer will not cope with it.

What is the server

Technically, the server computer begins with the motherboard and central processor. The general logic here is the same as in by the usual computer. But there are several general differences - processors on motherboard Maybe a few, and slots for connecting random access memory Radically more than it is accepted in the most advanced personal computers.

If on top personal Intel Core i7-2600K is supported up to 32 gigabytes of RAM, it is still not the most Intel Xeon. Processor X5570 is quite capable of working with 144 gigabytes! Moreover, if the processor desktop computer Typically, two or quad-core, then server chips have at least ten nuclei. In the example above, the number of cores, by the way, is equally.

It is worth noting that if intel and AMD are generally leading in the personal computer market, the IBM, HP, Oracle and Fujitsu also have a significant role in the server solutions segment. At the same time, if the X86 architecture is now popular in the personal segment, then in the server, almost all significant market players continue to offer their own technological solutions, you can mention Intel IA-64, Aibeam Power and collaborative for Oracle and Fujitsu - SPARC. This in turn imposes certain restrictions, since the capabilities of the server software are directly related to the solutions of manufacturers.

What all manufacturers converge - so this is in the ability of servers to t. N. Hardware virtualization is a very pressing function, especially for hosting sites - you can immediately run several on the same server. virtual machines - And they all work almost with the same speed as himself physical server. as such.

In general, server computers are fast and powerful. But everything has its own price. Server operation is high power consumption. It is not necessary to spend energy for unnecessary goals to anyone, so such familiar hardware functions, for example, a sound controller or USB channels in the server version are simply absent. The video card is also often absent or present in an extremely limited form. As a rule, everything you need to initially configure or see the server operator can be done by command line - Cool video card for this is not required.

Eight megabytes of video memory for the server is normal, much more important is the amount of RAM. It's not easy thing in the desire for perfection, when the engineer wants to insert memory into the slot, since there is a slot. The problem is that modern hard drives have not yet stepped over the line of several terabytes, for obtaining large volumes they are combined into the so-called. RAID arrays, but the whole set of hard drives still need to be physically twist (as a speed of 10 thousand rpm?) And read, the operational memory allows you to temporarily store quite large amounts of data to accelerate access.

Types of servers

Externally, server computers are two types - tower and rack. The tested version, he also "box" - can have practical same dimensions as the personal computer, the case is made of durable massive steel, whose task is to absorb vibrations and noise.

In practical scales, the option of racking servers is more common - computers are installed in special mounting cabinets that themselves are in a special room - server room. The rack option looks like a box of a desk or a large car radio.

When setting up the rack servers, it is necessary to understand not only with power supply and noise reduction, but also with cooling. It comes to the point that servers operators work in the server rooms in winter clothes, because if you turn off the air conditioner, the servers will very quickly overheat and begin to collapse. On the other hand, the server rack is easy to expand - a new server is simply purchased into the mounting closet and is installed as needed, this is the "hot connection".

As for operators and command line, which is enough to configure the server, it is in fact so - in contrast to the market of operating systems for personal computers, where they are leading microsoft solutions, in the server of the server software dominate Unix-like systemsIn other words, Linux. And these oS Even in a personal version, until recently, not very sought to graphic interfaces.

In addition to the operating system, of course, other necessary applications can be installed, depending on which tasks in front of the computer.

How to replace the server?

Thus, you can come to the following: if you need to get new shades of pleasure from computer Games Or multimedia, or distribute your files to all neighbors around the house, then buying a server computer for this is not worth it.

Just just a good model of modern personal computer. If you have any scientific or business tasks for which significant calculations and data volumes are required, then in this case it is the domestic operation of the server computer that will be not a very common idea - you will have electricity bills, the costs of operator services will appear. - Administrator (tune and check still needed), it will also be necessary to re-equip the almost integer room, giving it into the power of computer iron.

Perhaps it is better to use the services of remote cloud services and server data centers, to the power of which you can access with a regular desktop computer, and specialists will take all the settings and maintenance. But if your desire is still very much - you need your own server and a point, then maybe you are time to simply create your own data center?

It is simply necessary to understand the appointment of new equipment or software. The concept of server and server equipment is familiar with almost everyone, but few understands his appointment and work.

The world was shrouded in the web of the Internet and almost any second person interacts with him every day. Communication with friends on Skype and in social networks, jobs of banks, communication mobile phones All this provides the Internet. Server equipment and is intended to connect the computer network.

Basic functions of server equipment

In such equipment, an important role is played by the PC, which connects the other personal computers Adapters and network. Server equipment must provide communication with all participants in the network. Connects all working PCs in enterprises, allows you to transmit and store data package. It is necessary that it ensures that it ensure the confidential transmission of information on the network and excluded the loss of data. Such equipment requires continuous operation. Most important tasks are solved from such a server.

Server equipment classification

There are quite a lot of servers classifications. Often they are separated by type of execution and by type of solvable tasks.

Execution Servers:

• ultrathins - take up little space, respectively, a little consumes energy;
• outdoor - have high flexibility and ease of increasing;
• for installation in the rack - combines data in processing centers, and used external sources Memory.

By type of tasks solved:

• web servers - Fast shipment and file processing;
• application servers - advanced information processing capabilities;
• the database server is designed for requests from users and processing business transactions;
• firewalls - accepting and not accepting requests from the Internet and local networks;
• mail servers - processes accepted and sent tasks;
• print servers - they make it possible to print documents to those computers that in this moment connected to the network;
• servers remote access - can contact the office through a mobile communication;
• fax servers - are a link between incoming and sent letters in the form of a bridge;
• server consoles are a configured server and ready to work.

Server equipment work

From the listed it follows that the "main computer" must be quite strong in power, to carry overload and work all 24 hours. When the server equipment is running, the programmers seek to minimize the process of configuring and correcting errors. But as the practice shows without programming specialists, no organization is required. Therefore, there is always this position in the state.

If a failure occurs in the entire system as a whole, not only computers will suffer. Such a failure is able to harm the entire enterprise. And this may apply to him with a tremendous damage. That is why server equipment must be well protected and work most effectively.

Conditions necessary for work:

• you should provide a room for server equipment;
• sufficient number of motherboards, hard disks and RAID disk arrays;
• the temperature in the room must be appropriate;
• the presence of competent, experienced programming specialists.

So that server equipment worked smoothly and most effectively, it must be constantly improved and updated. Firms specializing in the production of components for computers offer various types of equipment. These are motherboards, and special processors, hard drives etc.

Choosing, server equipment, do not look at the cost. Expensive - this does not mean good, and cheap is another unprofitable option. Therefore, it is not necessary to take into account. Watch is necessary on functionality. And, choosing such equipment, it is desirable to consult from specialists.

Greetings to your blog site. From this article you will learn what server is, his role and what kinds they are. Many of us are familiar with the concept itself, because few people boast that when using the Internet and viewing sites, he never popped the "Server not available".

But the meaning of this term knows far from all, so we will try to study all the nuances in the most detail regarding what Server is, and what is it used for. In parallel, we look at the varieties of servers and their main differences from each other.

Concept Server

So what is a web server? This is a special hardware device that allows you to perform certain tasks on the Internet. However, such installations can be used not only remotely, but also locally. They are kept especially important information from firms and companies, educational and other institutions. It is only the smallest example of using the Servak, as they call it on the jargon programmers and users.

Meaning of the word

What denotes the word server in network technologies? If you briefly stay on the origin of the term itself, then it originates from the English verb "to serve", which literally means "serve". And if you compare it with the principle of work of the modern server, you can mark a close relationship.

The main purpose of the server is just to serve as storage of files and a document, and the coordinator of the work of many systems. Even novice computer users know that numerous processes relating to the operation of computer equipment and websites depend on the normal operation of the server. Therefore, it is imperative that the server computer regularly receive the necessary maintenance from specialists in the field of programming and computer technology.

Previously, the servers were directly in the "System Station" - the system unit - stationary computers. But it was very uncomfortable, as users often had to buy additional "boxes" for storing all the necessary information. But at the end of 2000 everything has changed, and today the server is the same computer, only more powerful. He can have the same structure as ordinary system unitOr form from several other components.

Like an ordinary computer, this unit works due to:

• powerful processor;
• motherboard;
• random access memory;
• winchester (hard disk).

That hardware May have different sizes - it all depends on the purpose and place of use. Varides its purpose.

Concept of server address

What is the server address? This is a set of characters, letters, designations that direct the user to a specific target computer. Usually under this concept, the system name is meant, but only if one specific domain works with a separate, only computer. It is noteworthy that the IP address is also a server determinant as a separate domain name.

Definition. If we talk simple wordsThe server is a computer designed to store files and information. In order to operate with data on the server, it is important for the user to know that the device must be connected to the Internet and the network of electric power around the clock. If we are talking about a private server, the owner may turn it on and off when it counts it right.

Thus, in the computer science, the server is a separate device, although it can be controlled by them using special programs through operating systems.

Server role and what is needed

What is server. computer network, we briefly sorted out. Now let's focus in the most detail on what the device is used for. That it can be stored in the desired and important informationThis is not a secret for anyone, but on this it is not ending.

So why do you need a server? This technique performs a number of essential functions, including:

1. Data storage various Internet Sites, portals, resources. For example, the servers are successfully used to save email files, media files. The so-called "cloud" on the Internet, where users unload various data, also takes a certain place on the server, and has its own address by which it can be found.
2. Providing and maintaining Internet providers. A person who only gathered to connect to the Internet, or wants to replace the provider (supplier) of Internet services, should know why you need a server, because it will be with him it will deal daily. To access world Wide WebThe client must make a fee. In this case, we are not talking about buying a router or Wi-Fi router. We are talking about making payment for the possibility of using the Internet provider server. This is nothing more than your IP address.
3. Storage of materials from different websites. It can be video, pictures, articles, folders and other content. In this case, we are talking about such a thing as the Internet hosting. Read more about Hosting and His difference from the server, read the link

Important! For normal operation of the servers requires a specially designed server software. This is done professional programmers, simple user Unable to secure normal maintenance of such complex equipment.

Concept server-client

Now let's focus on what server is and what is a client. With the first concept, we have already figured out, now consider the second. The client is the one who gets access to the place on the server computer. It may be one person, or a whole company.

That is, if you have your personal site on the Internet, then for his work you will need a place to store all files. When using finished engines for such resources, developers provide a disk space - for free or for a specific fee. In this case, the site owner is a client of a company providing hosting.

If the site was developed from scratch, on its own engine, and the owner has plans for further development This business, then it can well acquire his own server. In such a situation, the entrepreneur is not a client. On the contrary, developing their own business, he can freely get a client base.

Also the client is called a person who requests specific file through the server. The second, in turn, receives access to it and transmits the client. The server itself does not spend any operations with this file.

What are the servers?

There are many types of servers, because the developers themselves and users classify them in their own way. But if we speak in general, it is most often taken into account gradation by type of solvable tasks. According to this criterion, the following types of servers are allocated:

1. Web server that helps the client get the requested file.
2. An application server that gives more features in information processing, and works on the principle of the application.
3. A server without data that is used for business transactions and processing user requests.
4. Proxy server that performs 2 basic functions. The first is the safe receipt by the user of information from the Internet. In this case, the server works on the mediator's principle. The second function is to save information in the cache local disk. This allows the user to receive this information re-without the next entry into the Internet.

This is still not all in terms of the question, what are the servers. There are other varieties, but they can be called a kind of subtypes of previously described species.

Another type of need to know is local. Local server - This is a specially designed program that allows programmers to create and develop sites without a mandatory access to the Internet. Such programs can work both professionals and beginners who want to associate their professional life with Internet technologies.

The server is the essence of the concept.

Server (from English to Serve - serve) - software and hardware component of the computing system that performs service functions in response to customer requests by providing it open access To certain resources.

The basis of the server's task is to execute customer or programs. Server is a purely utilitarian thing that is intended for execution specific tasks. The main property of the server is to fulfill or solve this or that task. That is why we advise first to determine the task that a certain server will subsequently be selected.

Balanced server.

A balanced server is the optimal combination of productivity, quality and prices to which the customer and the seller are striving. The selection of such a combination is our overall task.

The task of selecting the optimal server is not trivial. We take into account many factors that do not even suspect the customer.

Often, the customer inadequately estimates the scale of tasks or requires a server for a specific specification, and not according to the tasks that they will be assigned. That is why the selection of the server, like its production itself, is the task of professionals. Our specialists face daily with the most diverse tasks, accumulate and systematize many years of experience in this area.

Server selection tactics.

This tactic, first of all, is to determine a number of tasks that will solve the server in the future, as well as the necessary productivity supply and scaling capabilities. In addition, it is necessary to find out whether the client needs in the server with a fault-tolerant scheme and finally navigate with the budget. If the tasks are superimpled by the allocated budget, then experts correct tasks or propose to raise the budget. An essential factor is the scalability of the solution for the ever-growing customer requirements. This will solve the problem with minimal initial and subsequent investments, reducing the cumulative cost of a ready-made solution.

The foregoing tactics in combination with the experience and professionalism of our specialists and managers allows our clients to get exactly the solution that they need.