Distributed Computing

Distributed Computing

A distributed system is a system, which consists of multiple autonomous computers, who communicate with each other through the computer network. These computers interact with each other, so that they can achieve a common set goal. Any computer program, which runs in a distributed system is known as "distributed program", whereas "distributed programming" refers to the process of writing any such programs. Distributed computing can also refer to the use of distributed system to solve computational problems. To make things simpler, a problem is divided into a number of tasks and each of the task is solved by one computer.

What is Distributed Computing

When one refers to the term 'distributed computing', either in 'distributed system' or in 'distributed programming' or 'distributed algorithm', it refers to computer networks, where individual computers are physically distributed within certain geographical area. These terms now have a wider meaning and refer to autonomous processes, which run on the same physical computer and communicate with each other by passing messages. It is very difficult to define distributed system, but each of these systems, do have certain properties, which are a part of the systems. They are:

    Although there are a number of autonomous computational entities, each of these have their own local memory.
    The different entities, who are a part of the system, communicate between each other by passing messages.
    The system should be able to tolerate problems or failures in individual computers.
    Often the structure of the system, inclusive of the types of network topologies, number of computers, etc. is not known in advance. There can be different kinds of computers and network links, which can be a part of the system. At the same time, there are chances of the system changing completely or partially, during the execution of a distributed program.
    A disadvantage of the system is, that each node or computer in the system has only limited and incomplete view of the entire system and each computer is able to view only part of the input.

Distributed Computing Environment

Distributed computing environment, acronym-ed as 'DCE', is an environment, which was developed in the early 1990's by a consortium. The framework and toolkit for developing client/server applications is supplied by distributed computing environment. Distributed computing environment is said to be a gigantic step in direction of standardization of architectures, which were initially dependent on the manufacturer. Like was the case with OSI model, DCE also did not gain success, however, the underlying concept prevailed.

Distributed Computing Principles Algorithms and Systems

When we start looking for distributed computing algorithms, there is a major confusion, which arises between 'concurrent computing', 'parallel computing' and 'distributed computing'. They overlap and making a clear distinction between them is a difficult task. Same system can have characteristics of parallel as well as distributed system, as the processors in a typical system often run concurrently. Parallel computing is often looked upon as a particular tightly coupled form of distributed computing and distributed computing is looked upon as a loosely coupled form of parallel computing. The basic criteria, which can be used to make the distinction is access to memory. In parallel computing, all processors share the memory, whereas in distributed computing, each processor has its own private memory. The distributed computing projects, which use message-passing models have certain characteristics.

    The designer of the algorithm is the only one, who is allowed to choose the computer program and all the computers run the chosen programs.
    It is necessary, that the system works correctly, irrespective of the structure of the network.
    There is a commonly used model, which is a graph with one finite-state machine per node.
    When one talks of distributed computing algorithms, the computational problems are typically related to graphs.
    More often than not, the graph, which describes the structure of the computer network is the problem instance.

Let's understand this better, with the help of an example.

Example of Distributed Algorithm
The graph G is a graph of structure of the computer network. There is one computer, which is located on each node of G and there is single communication link for each edge of G. In the beginning, each computer, who is a part of the graph knows only about its immediate neighbors in the graph. In order to discover each other, the computers have to exchange messages with each other. This will also help them to discover more about the structure of graph G. It is mandatory, that each computer produces its own color as output. The main focus of this algorithm is to coordinate the operation of any arbitrary distributed system.

There are various distributed computing software, that have now been developed. Distributed computing is used in various fields ranging from Biology and Medicine, to Earth Sciences, Mathematics (but naturally), Physics and Astronomy, as well as Multi-Applications projects. There are also a number of upcoming projects, in the field of artificial intelligence, as well as non-specialized projects, some of which are also based in the field of plasma technology.

Computer Networking

Computer Networking

A computer network is a system of networks where computers are interconnected via peer-to-peer connection or client-server connection to share data, information and resources. Computer networking is the engineering discipline which concerns itself with the communication between computer systems and devices. Computer networking is not an independent science since it extensively derives most of its theoretical and practical aspects from other communications technology disciplines like telecommunications, information technology, computer science and computer engineering. It can be called a sub-discipline of these four major disciplines. Let us take a brief look at computer networking basics and get to understand how it all works.

Computer Network Types

There are four major types of computer networks:

    LAN or Local Area Network which is a network of computers within a very small area, say one building. Its most distinguishing characteristics are high data exchange rates, very small geographic area coverage and no requirement for leased telecommunication lines.
    MAN or Metropolitan Area Network which is a network covering a larger area than LAN, say a network of all computers within a city. A MAN may be owned and operated by a single organization but is used by a larger number of individuals and organizations. MAN may also be used in cable television.
    WAN or Wide Area Network which covers a larger geographic area than either LAN or MAN. WAN offers four connection options - leased lines, circuit switching, packet switching and cell relay.
    Wireless LAN/WAN is the wireless variant of the LAN or WAN and is related to telecommunications network where the nodes are interconnected without the use of wires or cables. Wireless networking is usually implemented using remote information transmission systems which use electromagnetic frequency for the network carrier and such an implementation generally occurs at the layer of the network.

Computer Networking Methods

Peer-to-Peer Networking: In this method, computers can be directly connected to each other and files and computer networking information can be accessed directly by connecting to another computer. However, for this to take place, it is necessary that the computer from which the data needs to be accessed is turned on. For instance, if Computer B requires the X-files from Computer A, it cannot do so if Computer A is turned off. The computers involved in a peer-to-peer network must be similar and run workstation operating systems.

Setting up a Peer-to-Peer Network:

    Start with installing the appropriate operating system.
    Shut down all the participant computers and the router (optional) and turn on just one computer which would be used to set up the router.
    Follow the instructions for setting up the router. These instructions may come as a manual or as a CD.
    After your router is configured, turn off both, the router and the computer.
    Connect each participating computer to the router using a separate RJ-45 cable for each connection and turn on the router. Turn on the computers after a few seconds of turning on the router. Soon, you will get a pop up indication of network detection.
    If setting up a wireless connection, you would need to connect a wireless router to one computer and configure the router following the configuration instructions.
    Install wireless network cards on all other computers. Turn on the router and computers as mentioned above.
    Because of the wireless network cards, the other computers won't be required to be physically connected to the router.

Read more about home computer networking tips to set up a network at home yourself!

Client-Server Networking: Under this form of networking, all the information and files are centralized on the server and any computer can access any information at any time, irrespective of the source computer's power status. For instance, extending the above example, Computer B can access the X-files of Computer A even if the latter is turned off. The files would be present on the server! One of the biggest advantages of this kind of networking is that there is network security as the computers are accessing all the data and information via the server, and not directly. The server computer is the single point of contact for all the client computers. Due to centralization of data, information and resources, client-server networking provides centralized backup facilities, Internet facilities and the assurance of Internet monitoring.

Setting up a Client-Server Network:

    First of all, you need a server. You can either purchase one or use an existing computer as a server. If you're using an existing computer as server, make sure it has a 133 MHz or higher speed processor, a minimum RAM of 128 MB, up to 2 GB of free hard disk space, CD-ROM or DVD-ROM drive and hardware that supports console redirection.
    Install a server operating system on the server computer and follow instructions for such installation very closely.
    The final step of installation would probably show you a dialog box confirming successful active directory installation. Your server is now a domain controller and ready for client access.
    Once the domain is created, client computer accounts can be created and added to it.

Computer Network Administration

The duties of a computer network administrator includes network maintenance and regulation of all systems and peripherals attached to the network. Windows XP Professional and Windows Server 2003 provide many tools for network management for both P2P as well as CS network administration. For P2P administration, Windows XP Professional offers local and small network tools which are sufficient for managing workstation. On the other hand, Windows Server 2003 provides lots of tools for remote management of servers as well as clients.

Internet Facts

Internet Facts

The Internet is a powerful liberalizing tool that has changed the way the world functions. One of the biggest Internet facts is that the borders between countries have been rendered useless in certain scenarios, and the transfer of data and information has become as simple as it gets. There is a growing concern that the Internet technology is beginning to get segregated today, with the whole debate about net neutrality making that clear, but in the meantime there is still plenty to enjoy about this wonderful power.

In most developed nations, Internet penetration and Internet access runs as deep as 75%, which means that a majority of the people are online. In developing nations and third world countries, the situation is not so bright. But the point is that this number is only going to rise further in all countries around the world, and pretty soon every single individual in the world can be connected to the world wide web.

Interesting Internet Facts

There are many fascinating aspects of the Internet, and some of the most interesting stories is about the birth, the evolution and the history of the Internet.

    The Internet was created in the 1960's by the United States defense organization. Read more on when was the Internet invented.
    In 1990, Tim Berners-Lee coined the term 'World Wide Web'.
    The very first hard drive was capable of storing only 5 MB of data.
    On an average, a person spends about 51 minutes per session surfing the net.
    This works out to about 25 hours a month surfing the Internet.
    Average view time for a webpage is about 45 seconds.
    Almost 80% of pictures on the Internet are of naked women. Internet censorship is a losing battle that many regulators are facing.

Amazing Internet Facts

One of the biggest achievements of the Internet is how fast it has actually grown. The power that this tool gives us is unlimited, and we have become information super-highways.

    The Internet achieved 50 million users in 5 years. It took the radio 38 years, and it took the TV 13 years to reach the same figure.
    Despite the high number of users, 80% of the world's population does not use the Internet.
    There is an Internet crime committed around the world every 10 seconds.
    Every year, about 2 million TB of data is created and stored.
    About 70% of Internet users are men.
    Total number of Internet users around the world is 2 billion approximately. This article on how does the Internet work will also be useful to you.

One of the biggest threats that the Internet brings is that of Internet addiction and Internet security.

Internet Facts for Kids

Children born in this age seem like they know everything about computers since the day they are born. To a certain extent this is true, because they grow up surrounded by this amazing technology around them.

    The first mouse was created by Douglas Engelbart in 1968.
    Mosaic, the first web browser was released in 1993.
    Sweden is country with the biggest percentage of Internet users, at 78%.
    HTTP stands for HyperText Transfer Protocol.
    Parents of 70% of child users have no idea what their kids are doing on the Internet. These Internet safety facts will also teach you more.
    There are about a billion websites running all around the world today.
    A person using the Internet blinks 10 times a minute, whereas a person not using the Internet will blink at least twice as many times.

All these interesting and weird Internet facts: Internet statistics show how powerful the web has really become. Simultaneously, the Internet has also achieved very little. There is still tremendous scope left for increasing the user base of people accessing the net around the world, and this is something that is slowly happening in many countries. Third world countries are lagging far behind in the field of Internet infrastructure, but over time they will catch up.

There are many disadvantages of the Internet as well, and this depends entirely on the person who uses this service. Sharing of information on the public domain is bound to have its negative effects, and this is something that countries are keeping an eye on. In the meantime, these Internet facts should be enough to keep you thinking for a while.

Internet and its Uses in Our Daily Life

Internet and its Uses in Our Daily Life

How difficult our life would have been if there was no Internet. Think about it. To find some information, we all have acquired the habit of 'Googling' it on the web; within a few seconds the screen displays the desired information. You want to book tickets for a movie night with friends, you can book them at the click of a button, again through the Internet media. Many of us cannot imagine life without the social networking sites. The Internet has indeed made the world a small place and living life easier. And the rapid progress of technology has made it possible to access the Internet from anywhere through plenty of means. It has such a plethora of uses in our daily life that we use it for one purpose or the other daily. The routine uses and some positive effects of the Internet in various sectors have been discussed in detail below.

The Uses of the Internet in Daily Life

For Information:
For a layman, Internet is nothing but a collection of websites. And there are innumerable websites that serve a variety of purposes. There are news websites, social networking websites, websites that provide information and websites of various businesses and organizations. These websites are updated frequently to provide information to the user. You can find everything of anything on the web just by browsing through a few websites. You can also use emails, blogs, IM chat, social networking websites and communication software for sharing your information with the world. The Internet has made access to information cheaper and easier and this is its most common use in daily life.

Business & Advertising:
Almost all the businesses these days have websites, through which they promote and advertise themselves. This medium these days has been used extensively for promotional campaigns. Not only promoting your business but you can also effectively advertise your event or any cause on this medium. There are many businesses that depend on the Internet for their survival like stocks and call centers, to name a few. It has promoted faster access to necessary information which strengthens the business processes.

Education:
Internet also is a popular medium used by students. Many students use it for educational purposes, like for finding study material or for applying to some college or university. It is now a virtual world and all the applications are done online through the website of the concerned educational body. Students use websites for these and many other purposes like checking exam results, exam schedule, application procedure to any course, etc. Students also take the help of the Internet for project help and for obtaining the required images. Everything on the Internet is a click away from us.

Communication & Networking:
The use of the Internet for networking is very popular among all age groups. There are many good social networking websites that are used by people for communication. These websites provide an effective and easy platform that facilitates interaction. In daily life, it is widely used as a means of communication through means like networking websites, chat websites, blogs, etc. Through these websites you can also share your photographs with your near and dear ones. The Internet is widely used by job seekers for job applications and job searching. Facilities like video conferencing has made it possible to conduct interviews online.

Entertainment:
Another popular use of the Internet in daily life is for entertainment. Facilities like listening to online music, downloading music and movies provides a platform for entertainment. There are plenty of other ways through which you can entertain yourselves on the Internet. You can play online games, view sports matches, or watch videos of your choice. It is a trusted means of entertainment for these kinds of purposes and is extensively used for the same.

Other Popular Uses:
It is popularly used for banking. Almost all the banking transactions are possible through this medium. Apart from these common uses, it can also be used for shopping. Online shopping is very popular among masses and on the Internet you can buy anything and get it delivered at home. There are also many people who use it to work from home.

These were some of the chief common uses of the Internet in our daily life. It is a boon for us and has made our life easy by facilitating so many uses. But it is also prone to attacks of many kinds that threaten safety over the Internet. To protect the Internet from these attacks we should all use it carefully and also protect ourselves from various privacy intrusions. The Internet as a tool for communication will always remain its most powerful use. The array of uses of the Internet is vast and with the progress of technology new uses will get added to the list of uses continuously.