web server

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MODULE: 2 WEB SERVER HARDWARE AND SOFTWARE A server is a system (software and suitable computer hardware) that responds to requests across a computer network to provide, or help to provide, a network service. Servers can be run on a dedicated computer, which is also often referred to as 'the server', but many networked computers are capable of hosting servers. In many cases a computer can provide several services and have several servers running. A server is any computer used to provide (or “serve”) files or make programs available to other computers connected to it through a network (such as a LAN or a WAN). The software that the server computer uses to make these files and programs available to the other computers is sometimes called server software. Sometimes this server software is included as part of the operating system that is running on the server computer. Thus, some information systems professionals informally refer to the operating system software on a server computer as server software, a practice that adds considerable confusion to the use of the term “server.” In short, Server refers to a computer or device on a network that manages network resources. Types of servers In a general network environment the following types of servers may be found. Application server, a server dedicated to running certain software applications Catalog server, a central search point for information across a distributed network Communications server, carrier-grade computing platform for communications networks Compute server, a server intended for intensive (esp. scientific) computations Database server, provides database services to other computer programs or computers Fax server, provides fax services for clients File server, provides remote access to files Game server, a server that video game clients connect to in order to play online together Home server, a server for the home Print server, provides printer services Proxy server, acts as an intermediary for requests from clients seeking resources from other servers 1 BY: VIKRAM.G.B Lecturer, P.G Dept of Commerce Vivekananda Degree College, Bangalore-55

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Page 1: web server

MODULE: 2

WEB SERVER HARDWARE AND SOFTWAREA server is a system (software and suitable computer hardware) that responds to requests across a computer network to provide, or help to provide, a network service. Servers can be run on a dedicated computer, which is also often referred to as 'the server', but many networked computers are capable of hosting servers. In many cases a computer can provide several services and have several servers running.

A server is any computer used to provide (or “serve”) files or make programs available to other computers connected to it through a network (such as a LAN or a WAN). The software that the server computer uses to make these files and programs available to the other computers is sometimes called server software. Sometimes this server software is included as part of the operating system that is running on the server computer. Thus, some information systems professionals informally refer to the operating system software on a server computer as server software, a practice that adds considerable confusion to the use of the term “server.”

In short, Server refers to a computer or device on a network that manages network resources.

Types of serversIn a general network environment the following types of servers may be found. Application server, a server dedicated to running certain software applications Catalog server, a central search point for information across a distributed network Communications server, carrier-grade computing platform for communications networks Compute server, a server intended for intensive (esp. scientific) computations Database server, provides database services to other computer programs or computers Fax server, provides fax services for clients File server, provides remote access to files Game server, a server that video game clients connect to in order to play online together Home server, a server for the home Print server, provides printer services Proxy server, acts as an intermediary for requests from clients seeking resources from other servers Sound server, provides multimedia broadcasting, streaming. Stand-alone server, a server on a Windows network that neither belongs to nor governs a Windows

domain Web server, a server that HTTP clients connect to in order to send commands and receive responses

along with data contents

Web server can refer to either the hardware (the computer) or the software (the computer application) that helps to deliver web content that can be accessed through the Internet. The most common use of web servers is to host websites, but there are other uses such as gaming, data storage or running enterprise applications.The primary function of a web server is to deliver web pages on the request of clients using the Hypertext Transfer Protocol (HTTP). This means delivery of HTML documents and any additional content that may be included by a document, such as images, style sheets and scripts.

Web servers are not always used for serving the World Wide Web. They can also be found embedded in devices such as printers, routers, webcams and serving only a local network. The web server may then be used as a part of a system for monitoring and/or administering the device in question. This usually means that no additional software has to be installed on the client computer; since only a web browser is required.

1 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Web servers are computers that deliver (serves up) Web pages. Every Web server has an IP address and possibly a domain name. For example, if you enter the URL http://www.pcwebopedia.com/index.html in your browser, this sends a request to the Web server whose domain name is pcwebopedia.com. The server then fetches the page named index.html and sends it to your browser.Any computer can be turned into a Web server by installing server software and connecting the machine to the Internet. There are many Web server software applications, including public domain software from NCSA and Apache, and commercial packages from Microsoft, Netscape and others.

Web Client/Server Communication: When a person uses a Web browser to visit a Web site, the Web browser (also known as a Web client) requests files from the Web server at the company or organization that operates the Web site. Using the Internet as the transportation medium, the request is formatted by the browser using HTTP and sent to the server computer. A moment later, when the server receives the request, it retrieves the file containing the Web page or other information that the client requested, formats it using HTTP, and sends it back to the client over the Internet.

Two-tier client/server architecture: Typical request message from a client to a server consists of three major parts: request line, optional request headers, and an optional entity body. This kind architecture has only one client and one server message that a Web client sends to request a file or files from a Web server

Three-tier and N-tier client/server architectures: Three-tier architecture extends the two-tier architecture to allow additional processing to occur before the Web server responds to the Web client’s request. Higher-order architectures - that is, those that have more than three tiers - are usually called n-tier architectures.

2 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Operating Systems for Web ServersMost Web servers run on computers that use one of the following operating systems:

Microsoft Windows NT Server, Microsoft Windows 2000 or 2003 Server products, Linux, or One of several UNIX-based operating systems, such as Solaris or FreeBSD.

Many companies believe that Microsoft server products are simpler for their information systems staff to learn and use than UNIX-based systems. Other companies worry about the security weaknesses caused by the tight integration between application software and the operating system in Microsoft products.UNIX based Web servers are more popular, and many users believe that UNIX is a more secure operating system on which to run a Web server.

Web Server Software

Computer software, or just software, is any set of machine-readable instructions (most often in the form of a computer program) that directs a computer's processor to perform specific operations.

Software is a general term. It can refer to all computer instructions in general or to any specific set of computer instructions. It is inclusive of both machine instructions (the binary code that the processor understands) and source code (more human-understandable instructions that must be rendered into machine code by compilers or interpreters before being executed).

Web server software includes a series of complex tools and programs that come together to create and manage a Web server. These tools range from programming language protocols to file transfer protocol programs, which allow programmers to customize their Web servers and provide unique experiences for their users from each of their Web pages.Web server software is used to edit and create Web pages along with various other HTTP formatted files.

The most popular Web server programs in use today: Apache HTTP Server, Microsoft Internet Information Server (IIS), and Sun Java System Web Server (JSWS) (often called by its former names, Sun ONE, iPlanet Enterprise Server and Netscape Enterprise Server).

Below is the percentage of Websites using different Web Server Software’s:- Apache 62.3%, Microsoft-IIS 16.6%, Nginx 15.7%, LiteSpeed1.9%, Google Servers1.4%, Tomcat 0.7%,

Lighttpd 0.5%, IBM Servers 0.4%, Yahoo Traffic Server 0.2%, Oracle Servers 0.2%, Zope 0.1%, Resin0.1%, Zeus0.1%

Apache HTTP Server:- The Apache HTTP Server Project is a collaborative software development effort aimed at creating a robust, commercial-grade, feature full and freely-available source code implementation of an HTTP (Web) server. The project is jointly managed by a group of volunteers located around the world, using the Internet and the Web to communicate, plan, and develop the server and its related documentation. This project is part of the Apache Software Foundation. In addition, hundreds of users have contributed ideas, code, and documentation to the project. This file is intended to briefly describe the history of the Apache HTTP Server and recognize the many contributors.

In February of 1995, the most popular server software on the Web was the public domain HTTP daemon developed by Rob McCool at the National Center for Supercomputing Applications, University of Illinois, Urbana-Champaign. However, development of that httpd had stalled after Rob left NCSA in mid-1994, and many webmasters had developed their own extensions and bug fixes that were in need of a common distribution. A small group of these webmasters, contacted via private e-mail, gathered together for the purpose of coordinating their changes (in the form of "patches").

3 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Using NCSA httpd 1.3 as a base, the group added all of the published bug fixes and worthwhile enhancements we could find, tested the result on our own servers, and made the first official public release (0.6.2) of the Apache server in April 1995.

There is a core group of contributors, formed initially of the project founders, and augmented from time to time by other outstanding contributors. There are 'committers', who are granted access to the source code control repositories to help maintain the project or docs, and the core group now managing the project, which is called the Apache HTTP Project Management Committee (PMC, for short). In fact, each Apache Software Foundation project has its own PMC, to determine committers, project direction and overall management. The terms "The Apache Group" or "Apache Core" are no longer used.

The original version of Apache was written for UNIX, but there are now versions that run under OS/2, Windows and other platforms. The name is a tribute to the Native American Apache Indian tribe, a tribe well known for its endurance and skill in warfare. A common misunderstanding is that it was called Apache because it was developed from existing NCSA code plus various patches, hence the name a patchy server, or Apache server.

Popular sites using Apache:- Youtube.com, Baidu.com, Wikipedia.org, Weibo.com, Tumblr.com, Mail.ru, Fc2.com, Ask.com, Apple.com, Craigslist.org, etc.,

Microsoft Internet Information Server:- Microsoft IIS comes bundled with current versions of Microsoft Windows Server operating systems. IIS is used on many corporate intranets because many companies have adopted Microsoft products as their standard products. Small sites running personal Web pages use IIS, as do some of the largest electronic commerce sites on the Web.

This Web server runs on Windows NT platforms. In fact, IIS comes bundled with Windows NT 4.0. Because IIS is tightly integrated with the operating system, it is relatively easy to administer. However, currently IIS is available only for the Windows NT platform, whereas Netscape's Web servers run on all major platforms, including Windows NT, OS/2 and UNIX.

Popular sites using Microsoft IIS:- Live.com, Msn.com, Microsoft.com, Conduit.com, Go.com, 360buy.com, Incredibar.com, Godaddy.com, Blogfa.com, Secureserver.net, etc.,

Nginx:- Nginx (pronounced engine-x) is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. Igor Sysoev started development of Nginx in 2002, with the first public release in 2004. Nginx now hosts nearly12.18% of active sites across all domains. Nginx is known for its high performance, stability, rich feature set, simple configuration, and low resource consumption.

nginx [engine x] is an HTTP and reverse proxy server, as well as a mail proxy server, written by Igor Sysoev. For a long time, it has been running on many heavily loaded Russian sites including Yandex, Mail.Ru, VKontakte, and Rambler.

Tested OS and platforms: FreeBSD 3 — 10 / i386; FreeBSD 5 — 10 / amd64; Linux 2.2 — 3 / i386; Linux 2.6 — 3 / amd64; Solaris 9 / i386, sun4u; Solaris 10 / i386, amd64, sun4v; AIX 7.1 / powerpc; HP-UX 11.31 / ia64; Mac OS X / ppc, i386; Windows XP, Windows Server 2003. Nginx is one of a handful of servers written to address the C10K problem. Unlike traditional servers, Nginx doesn't rely on threads to handle requests. Instead it uses a much more scalable event-driven (asynchronous) architecture. This architecture uses small, but more importantly, predictable amounts of memory under load.

4 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Popular sites using Ngix:- Sina.com.cn, Yandex.ru, Wordpress.com, Vk.com, 163.com, Pinterest.com , Soso.com, About.com, Cnn.com, Imgur.com, etc.,

Electronic Mail (E-Mail)Electronic mail originated in the 1970s on the ARPANET. Although the goals of the ARPANET were to control weapons systems and transfer research files, general communications uses emerged on the network. In 1972, Ray Tomlinson, an ARPANET researcher, wrote a program that could send and receive messages over the network.

E-Mail BenefitsOne useful feature of e-mail is that documents, pictures, movies, worksheets, or other information can be sent along with the message itself. These attachments are frequently the most important part of the message.

E-mail DrawbacksDespite its many benefits, e-mail does have some drawbacks. One annoyance associated with email is the amount of time that businesspeople spend answering their e-mail today. A second major irritation brought by e-mail is the computer virus, more simply known as a virus, which is a program that attaches itself to another program and can cause damage when the host program is activated.

Spam: The sheer magnitude of the spam problem is hard to believe. During one 24-hour period in 2005, researchers estimated that 106 billion spam e-mail messages were sent. Many researchers who track the growth in spam believe that current trends will continue and that more than 90 percent of all e-mail messages (including messages transmitted to both business and personal users) will be spam before any effective technical solutions can be implemented. Other researchers believe that the growth of spam is showing signs of leveling out.

Web Site and Internet Utility Programs

Finger and Ping Utilities:- Finger is a program that runs on UNIX operating systems and allows a user to obtain some information about other network users. A Finger command yields a list of users who are logged on to a network, or reports the last time a user logged on to the network. Many organizations have disabled the Finger command on their systems for privacy and security reasons.A program called Ping, short for Packet Internet Groper, tests the connectivity between two computers connected to the Internet. Ping provides performance data about the connection between Internet computers, such as the number of computers (hops) between them. It sends two packets to the specified address and waits for a reply. Network technicians often use Ping to troubleshoot Internet connections.

Tracert and Other Route-Tracing Programs:-Tracert (TRACE Route) sends data packets to every computer on the path (Internet) between one computer and another computer and clocks the packets’ roundtrip times. This provides an indication of the time it takes a message to travel from one computer to another and back, ensures that the remote computer is online, and pinpoints any data traffic congestion. Routetracing programs also calculate and display the number of hops between computers and the time it takes to traverse the entire one-way path between machines. Route-tracing programs such as Tracert work by sending a series of packets to a particular destination. Each router along the Internet path between the originating computer and the destination computer reports its IP address and the time it took to reach it. After the program completes its packet transmissions, it displays the number of hops and how much time it took to reach each node and travel the entire path.

5 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Telnet and FTP Utilities:- Telnet is a program that allows users to log on to a computer that is connected to the Internet. This remote login capability can be useful for running older software that does not have a Web interface. Several Telnet client programs are available as free downloads on the Internet, and Microsoft Windows systems include a Telnet client called Telnet.exe. Telnet lets a client computer give commands to programs running on a remote host. Telnet programs use a set of rules called the Telnet protocol.The File Transfer Protocol (FTP) is the part of the TCP/IP rules that defines the formats used to transfer files between TCP/IP-connected computers. FTP can transfer files one at a time, or it can transfer many files at once. FTP also provides other useful services, such as displaying remote and local computers’ directories, changing the current client’s or servers active directory, and creating and removing local and remote directories.

Indexing and Searching Utility Programs:- Search engines and indexing programs are important elements of many Web servers. Search engines or search tools search either a specific site or the entire Web for requested documents. An indexing program can provide full-text indexing that generates an index for all documents stored on the server.

Data Analysis Software:- Web servers can capture visitor information, including data about who is visiting a Web site (the visitor’s URL), how long the visitor’s Web browser viewed the site, the date and time of each visit, and which pages the visitor viewed. This data is placed into a Web log file. As you can imagine, the file grows very quickly - especially for popular sites with thousands of visitors each day.

Link-Checking Utilities:- Dedicated site management tools include a standard set of features, starting with link checking. A link checker examines each page on the site and reports on any URLs that are broken, seem broken, or are in some way incorrect. It can also identify orphan files. An orphan file is a file on the Web site that is not linked to any page. Other important site management features include script checking and HTML validation. Some management tools can locate error-prone pages and code, list broken links, and e-mail maintenance results to site managers.On the company Web site, it is important to regularly check links that point to pages both within and outside the corporate Web site. Some Web server software does contain link-checking features. A dead link, when clicked, displays an error message rather than a Web page. Maintaining a site that is free of dead links is vital because too many dead links on a site can cause visitors to jump to another site. Web-browsing customers are just a click away from going to a competitor’s site if they become annoyed with an errant Web link.

Remote Server Administration:- With remote server administration, a Web site administrator can control a Web site from any Internet-connected computer. Although all Web sites provide administrative controls – most through a workstation computer on the same network as the server computer or through a Web browser - it is convenient for an administrator to be able to fix the server from wherever he or she happens to be.

6 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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WEB SERVER HARDWARE

Companies use a wide variety of computer brands, types, and sizes to host electronic commerce operations. Some small companies can run Web sites on desktop PCs. Most electronic commerce Web sites are operated on computers designed for site hosting.

Server ComputersWeb server computers generally have more memory, larger (and faster) hard disk drives, and faster processors than the typical desktop or notebook PCs with which you are probably familiar. Many Web server computers use multiple processors; very few desktop PCs have more than one processor. Because web server computers use more capable hardware elements and more of these elements, they are usually much more expensive than workstation PCs.

Web Server Performance Evaluation

Benchmarking Web server hardware and software combinations can help in making informed decisions for a system. Benchmarking, in this context, is testing that is used to compare the performance of hardware and software. Elements affecting overall server performance include hardware, operating system software, server software, connection speed, user capacity, and type of Web pages being delivered. When evaluating Web server performance, a company should know exactly what factors are being measured and ensure that these are important factors relative to the expected use of the Web server. Another factor that can affect a Web server’s performance is the speed of its connection.A server on a T3 connection can deliver Web pages to clients much faster than on a T1 connection. The number of users the server can handle is also important. This can be difficult to measure because results are affected by the server’s line speed, the clients’ line speeds, and the sizes of the Web pages delivered. Two factors to evaluate when measuring a server’s Web page delivery capability are throughput and response time. Throughput is the number of HTTP requests that a particular hardware and software combination can process in a unit of time. Response time is the amount of time a server requires to process one request. These values should be well within the anticipated loads a server can experience, even during peak load times.

Measuring web server response time: The most important factor to look at is high water mark of HTTP requests per second and end-to-end response time during this high-usage period. This response time is the total elapsed time between receipt of the request and the end of sending the requested HTML. Some use the "Time To First Byte"(TTBF) metric to measure web server response time.

Depending on tolerance for 404 timeouts and response time during peak usage times, can choose web server hardware to minimize disk latency (caching) while ensuring that have enough CPU and RAM for the OS. Most companies choose Intel-based web server hardware on a server with high-channel disks (to support high volume disk reads) and expandable RAM to cache the most frequently requested pages and images. Need to choose a server that has expandable RAM capacity, at least 4 gig with expansion to 16 gig, depending on the size of working set of frequently-referenced pages and images.

The best configuration for web servers

To have the appropriate web server configuration, a web server without a web cache is experiencing stress the cause is most likely disk enqueue requests. The average disk latency is 15-20 milliseconds and it does not take much traffic to cause disk enqueues.

7 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Disk placement counts: While hosting if we have images and HTML on adjacent cylinders latency can be experienced from the movement of the read-write heads. Disk I/O latency goes up, and the disk will shake like an out-of-balance washing machine as competing HTTP requests try to get their images and HTML. One can use the Linux iostat utility to monitor disk latency.

Web Servers are not CPU intensive: Servicing an HTTP request does not involve high CPU consumption. One can monitor their web server CPU consumption with the Linux top and vmstat utilities, and have CPU enqueues when the runqueue exceeds the number of processors on the web server. However, one can utilize idle CPU resources by installing HTTP compression to improve web server HTML delivery speed, trading off unused CPU cycles for faster web response time.

RAM matters most - Most web servers have some pages that are far more popular than others, and caching the most popular images will dramatically improve total response time. Without a web cache, RAM usage should be minimal, but you should monitor for real RAM page-in conditions using vmstat, where page-in's correlate with scan rate. Remember, page-in's occur as a normal part of program loading, and you must separate normal page-in's from those caused by server swapping.

Minimum Requirements for a Web Server:

Basic Requirements: 1. Server access via FTP, SSH or Telnet in order to install movable type.2. Web Server Configured to execute CGI scripts written Perl, the language which Movable type is

written in.3. Web browser with javascript enabled to access to movable type application once installed on

the server. Hardware requirements:

The specific requirements for Movable Type vary greatly depending upon the specific traffic and usage patterns being planned for. However, the minimum recommended setup includes a single machine with:

o 1 GHz CPU;o 512 MB RAM;o 100 MB of available disk space for the application and dependencies.

Note on Disk Space: The application itself may require up to 20 MB of disk space. It should be noted however that this does not include the disk space required for your published blog content. The amount of disk space required for published content will depend both on the number of blogs deployed and the amount of data published on each blog.

Operating System: Movable Type has been is routinely tested on and is supported on the following operating systems, but may work on other recent systems:

o All flavors of Unix including: Mac OS X Solaris, SunOS RedHat Enterprise, Fedora and CentOS Linux BSD

o Windows Server

Web Server Hardware ArchitecturesAdministrators of large Web sites must plan carefully to configure their Web server computers, which can number in the hundreds or even thousands, to handle the daily Web traffic efficiently. These large collections of servers are called server farms because the servers are often lined up in large rooms, row after row, like crops in a field.

8 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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One approach, sometimes called a centralized architecture, is to use a few very large and fast (and very expensive) computers.

A second approach is to use a large number of less powerful computers and divide the workload among them. This is sometimes called a distributed architecture or, more commonly, a decentralized architecture.

Large decentralized sites must use load-balancing systems (divide the workload among them). A load-balancing switch is a piece of network hardware that monitors the workloads of the servers attached to it and assigns incoming web traffic to the server that has the most available capacityIn a simple load-balancing system, the traffic that enters the site from the Internet, encounters the load-balancing switch, which then directs the traffic to the web server best able to handle the traffic

Usual Steps in Developing Web Server:

Step 1 - The computer: A Web server requires a dedicated computer that is directly connected to the Internet, usually through an Ethernet network (LAN/WAN). Web server can be run on a low-end computer, but if server wants to be responsive to Web surfers a more powerful computer (such as a Pentium or PowerPC-based Macintosh) should be used. A Web server needs a fast and large hard drive and should have lots of RAM.

Step 2 - The operating system software: The following operating systems can support a Web server: Windows/NT, Windows/95, MacOS, Unix, and Linux. Of these, most of the existing Web servers run on Windows/NT, MacOS (on a PowerMac) or Unix. Linux is a PC/DOS-based version of Unix.

Step 3 - The networking software: All Internet computers need TCP/IP, and a Web server is no exception. As stated above, server computer should be directly connected to the Internet and thus may require appropriate Ethernet software.

Step 4 - The Web server software: There are a variety of Web server programs available for a variety of platforms, from Unix to DOS machines. For the Macintosh, a popular Web server is WebStar from StarNine. For the Windows/NT platform, both Microsoft and Netscape offer a powerful Web server program free to educational institutions. The web server software can be downloaded or purchased and that need to be installed in computer using the instructions provided.

9 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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Step 5 - Configuring Web server: As soon as Web server has been installed it will be prompted for basic settings - default directory or folder, whether to allow visitors to see the contents of a directory or folder, where to store the log file, etc. Depending on the Web software installed, have to configure the software per the instructions that come with it.

Step 6 - Managing your Web server: As Web server is accessed by more and more people, it need to monitor the log file to see which files people are reading, identify peak access times, and consider upgrading computer. If required more RAM may be added and disk space to Web server computer to improve its performance. Also should check for bottlenecks - such as TCP/IP software.

Step 7 - Getting more information on operating a Web server

WEB HOSTING

A web hosting service is a type of Internet hosting service that allows individuals and organizations to make their website accessible via the World Wide Web.Web hosts are companies that provide space on a server owned or leased for use by clients, as well as providing Internet connectivity, typically in a data center. Web hosts can also provide data center space and connectivity to the Internet for other servers located in their data center, called collocation. The most basic is web page and small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP) or a Web interface. The files are usually delivered to the Web "as is" or with minimal processing. Many Internet service providers (ISPs) offer this service free to subscribers. Individuals and organizations may also obtain Web page hosting from alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or inexpensive. Business web site hosting often has a higher expense.

Domain Name: A domain name is a unique word, or a couple of words, usually associated with an IP address, that represents a special place on the Internet. Domain name (sometimes referred to as a URL) is website’s online address. People who type a domain name (such as facebook.com) into their Internet browsers will be directed to that website.

Multi-domain Hosting: Many hosts now offer what is called 'Multi-domain' web hosting where one can host more than one domain/website on the one plan. One may only intend to host one website at this point, but it can be a great advantage to have the future option should the need arise, to host more, at no extra cost. It means a person can host business website and still host a family or personal interest website as well. Again hosts should offer scalable plans, depending on how many domains user wish to host. And again some hosts will advertise 'unlimited' domains on their plans, but this may be qualified within their Terms and Conditions and is definitely limited by the plans disk storage amount.

Shared HostingShared hosting, also called virtual hosting, is the hosting of multiple websites on the same web server. With shared hosting, a web hosting company provides the user storage space and makes the website's files accessible to others via the internet. The web host also maintains the server and provides technical support for it. Perhaps the greatest advantage of shared hosting is that its efficient use of resources means that it costs much less than most other types of website hosting. Shared Hosting is normally all that most users require. The choice of plans available offers everything the average user will require and more. The alternatives to shared hosting include VPS, Semi Dedicated and Dedicated servers which as the name suggest gives either less websites hosted with particular website or a server completely reserved for user website.

10 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

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However, this can be very costly and really only needed for specific high-end websites with very high data storage, transfer rates etc. They will also require various levels of management skills in order to administer these servers.

VPS [Virtual Private Servers]Virtual Private Servers have recently been gaining huge popularity among small businesses and web developers who need the flexibility and stability of a dedicated server but are not yet ready to get their own dedicated server. Here are a few reasons why should one take advantage of a Virtual Private Server, if current shared hosting account does not fit for their growing online requirements anymore:

Complete Isolation from other VPS users: Although it shares one physical server with other VPS's, each VPS operates exactly like an independent stand-alone server, thus being insulated from the actions and abuses of other users on the same physical server.

Combines the best characteristics of shared and dedicated hosting: VPS combine the affordability and simplicity of using a shared account with the reliability and independence offered by a dedicated server. Thus VPS offer a tremendous amount of flexibility at a very reasonable cost.

Much cheaper than a dedicated hosting solution: VPS is much cheaper than a dedicated server, but has many of the features typical of a dedicated server such as a dedicated web server and mail server, as well as dedicated storage, memory, CPU and network bandwidth.

A multi-purpose dedicated solution: One can use a Virtual Private Server for almost all dedicated server purposes such as off-site data storage, web application hosting, application development, virtual desktops etc. One can also set up a VPS for running own web hosting and email services.

Unique partitioning technology: The uniqueness of the VPS technology lies in the possibility for a web server to be divided into separate independent mini-servers, where each user will be completely isolated from the other users in terms of software.

Ability to run your own Operating System: Each Virtual Private Server can run its own full-fledged operating system, meaning that you can install almost any software that runs on the respective OS and make any configuration change according to your current demands.

Full Administration Control: Each Virtual Private Server can be independently rebooted, which means that you will be able to personally restart your VPS as if you were an administrator in the data center.

Monitoring Capabilities: A VPS allows one to monitor resource utilization for CPU, system, disk space and disk inodes. It will be able to view detailed traffic statistics and even format and reload ones’ own VPS if needed.

Get more resources than pay for: The VPS technology allows only several users to actively use the available resources even when the VPS system capacity is full, which means that each account receives the full server processing power whenever the need arises.

Semi DedicatedA semi-dedicated server is an excellent solution for medium traffic web sites, including forums and Content Management Systems (CMS), which require more server resources such as disk space, server processing power (CPU) and RAM memory for their trouble-free functioning and online growth.

11 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55

Page 12: web server

Limited number of users per server: Switching to a semi-dedicated server sets one free from the limitations typical of shared hosting. This may sound like a VPS solution, but actually there is a big difference here, since one share a server with a limited number of users, which suggests more resources per user and the same administrative support that anyone would get on a dedicated server.

Dedicated Resources: On a semi-dedicated server user share one server with a maximum number of others, meaning that user actually uses a big part of the resources. Having a large portion of a dedicated server's capacity at user disposal, one can use much greater amount of CPU, RAM and all other resources crucial to the smooth functioning and growth of website.

Better Performance: The increased amount of server resources that user receive on a semi-dedicated server have direct impact on the load speed, the database access times, the number of applications one can run and much more.

Total Control: With a semi-dedicated server you can perform all management tasks related to your web sites through a simple and user-friendly interface, thus having total control over your web presence in terms of maintenance and monitoring

Guaranteed Security: With a large portion of the server resources available for you to use, you will not be encountering slow resolution speeds, so you can always feel secure about the smooth operation of your web sites. Furthermore, as a semi-dedicated user you will be protected against any resource abuses, that shared and VPS hosting servers are usually subject to.

DedicatedDedicated servers provide with unrestricted hosting resources for total independence in building and managing online presence. User will be a Webmaster of his own server machine offering a robust hardware configuration, powerful server characteristics and stable network parameters.Any of the server setups comes with its own Operating System installation of user choice. Due to the ensured root or administrator access to the server, user will be able to install and configure any software that he need. To manage own dedicated server, one will need to possess advanced administration skills or get assistance from a qualified server administrator. User could also consider taking advantage of a host’s optional backup administration, software installation and troubleshooting services.

12 BY: VIKRAM.G.BLecturer, P.G Dept of Commerce

Vivekananda Degree College, Bangalore-55