Shared web hosting service
Encyclopedia
A shared web hosting service or virtual hosting service or derive host refers to a web hosting service
where many websites reside on one web server
connected to the Internet. Each site "sits" on its own partition, or section/place on the server
, to keep it separate from other sites. This is generally the most economical option for hosting, as many people share the overall cost of server maintenance.
Shared hosting typically uses a web-based control panel system, such as cPanel
, DirectAdmin
, Plesk
, InterWorx
, H-Sphere
or one of many other control panel products. Most of the large hosting companies use their own custom developed control panel. Control panels and web interfaces can cause controversy however, since web hosting companies sometimes sell the right to use their control panel system to others. Attempting to recreate the functionality of a specific control panel is common, which leads to many lawsuits over patent infringement.
In shared hosting, the provider is generally responsible for managing servers, installing server software, security updates, technical support, and other aspects of the service. Most servers are based on the Linux
operating system
and LAMP (software bundle)
, which is driven by the reliability and security of open source
software such as Linux and Apache (the 'L' and 'A' of LAMP). Some providers offer Microsoft Windows
-based or FreeBSD
-based solutions. For example, the Plesk
control panel is available for two operating systems, Linux and Windows. Server-side facilities for either OS have similar functionality (for example: MySQL
(database) and many server-side programming languages (such as the widely used PHP
web programming language) under Linux, or the proprietary SQL Server
(database) and ASP.NET
programming language under Windows).
There are thousands of shared hosting providers in the United States
alone. They range from mom-and-pop shops and small design firms to multi-million-dollar providers with hundreds of thousands of customers. A large portion of the shared web hosting market is driven through pay per click
(PPC) advertising or Affiliate
programs.
Shared web hosting can also be done privately by sharing the cost of running a server in a colocation centre
; this is called cooperative hosting.
serve multiple hostnames on a single machine with a single IP address
. This is possible because when a web browser
requests a resource from a web server
using HTTP/1.1 it includes the requested hostname as part of the request. The server uses this information to determine which web site to show the user.
Web hosting service
A web hosting service is a type of Internet hosting service that allows individuals and organizations to make their own website accessible via the World Wide Web. Web hosts are companies that provide space on a server they own or lease for use by their clients as well as providing Internet...
where many websites reside on one web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
connected to the Internet. Each site "sits" on its own partition, or section/place on the server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
, to keep it separate from other sites. This is generally the most economical option for hosting, as many people share the overall cost of server maintenance.
Description
The hosting service must include system administration since it is shared by many users; this is a benefit for users who do not want to deal with it, but a hindrance to power users who want more control. In general shared hosting will be inappropriate for users who require extensive software development outside what the hosting provider supports. Almost all applications intended to be on a standard web server work fine with a shared web hosting service. But on the other hand, shared hosting is cheaper than other types of hosting such as dedicated server hosting. Shared hosting usually has usage limits and hosting providers should have extensive reliability features in place.Shared hosting typically uses a web-based control panel system, such as cPanel
CPanel
cPanel is a Linux based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site...
, DirectAdmin
DirectAdmin
DirectAdmin is a graphical web-based web hosting control panel designed to make administration of websites easier.- System requirements :DirectAdmin is compatible with several versions of Red Hat, Fedora Core, Red Hat Enterprise Linux, CentOS, FreeBSD, Ubuntu and Debian.The following specifications...
, Plesk
Plesk
The Parallels Plesk Panel software package is a commercial web hosting automation program. Originally released under the U.S. company Plesk Inc. and designed in Novosibirsk, Russia, Plesk was acquired by SWSoft in July 2003...
, InterWorx
InterWorx
InterWorx is web hosting control panel software developed by Interworx LLC. InterWorx was originally developed as an internal project of Nexcess.net LLC in the early 2000's, and was spun-off in 2004. The InterWorx control panel has also been referred to as the InterWorx Cluster Panel as it's...
, H-Sphere
H-Sphere
H-Sphere is a web hosting Automation Control Panel for shared web hosting services that was developed by Positive Software and acquired by Parallels, Inc. in September 2007. It is available for Linux, Unix and Windows environments and works with MySQL, PostgreSQL and Microsoft SQL Server databases...
or one of many other control panel products. Most of the large hosting companies use their own custom developed control panel. Control panels and web interfaces can cause controversy however, since web hosting companies sometimes sell the right to use their control panel system to others. Attempting to recreate the functionality of a specific control panel is common, which leads to many lawsuits over patent infringement.
In shared hosting, the provider is generally responsible for managing servers, installing server software, security updates, technical support, and other aspects of the service. Most servers are based on the Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
and LAMP (software bundle)
LAMP (software bundle)
LAMP is an acronym for a solution stack of free, open source software, referring to the first letters of Linux , Apache HTTP Server, MySQL and PHP , principal components to build a viable general purpose web server.The GNU project is advocating people to use the term "GLAMP" since what is known as...
, which is driven by the reliability and security of open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
software such as Linux and Apache (the 'L' and 'A' of LAMP). Some providers offer Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
-based or FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
-based solutions. For example, the Plesk
Plesk
The Parallels Plesk Panel software package is a commercial web hosting automation program. Originally released under the U.S. company Plesk Inc. and designed in Novosibirsk, Russia, Plesk was acquired by SWSoft in July 2003...
control panel is available for two operating systems, Linux and Windows. Server-side facilities for either OS have similar functionality (for example: MySQL
MySQL
MySQL officially, but also commonly "My Sequel") is a relational database management system that runs as a server providing multi-user access to a number of databases. It is named after developer Michael Widenius' daughter, My...
(database) and many server-side programming languages (such as the widely used PHP
PHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
web programming language) under Linux, or the proprietary SQL Server
Microsoft SQL Server
Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
(database) and ASP.NET
ASP.NET
ASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
programming language under Windows).
There are thousands of shared hosting providers in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
alone. They range from mom-and-pop shops and small design firms to multi-million-dollar providers with hundreds of thousands of customers. A large portion of the shared web hosting market is driven through pay per click
Pay per click
Pay per click is an Internet advertising model used to direct traffic to websites, where advertisers pay the publisher when the ad is clicked. With search engines, advertisers typically bid on keyword phrases relevant to their target market...
(PPC) advertising or Affiliate
Affiliate
An affiliate is a commercial entity with a relationship with a peer or a larger entity.- Corporate structure :A corporation may be referred to as an affiliate of another when it is related to it but not strictly controlled by it, as with a subsidiary relationship, or when it is desired to avoid...
programs.
Shared web hosting can also be done privately by sharing the cost of running a server in a colocation centre
Colocation centre
A colocation centre or colocation center , is a type of data centre where equipment space and bandwidth are available for rental to retail customers...
; this is called cooperative hosting.
Implementation
Shared web hosting can be accomplished in two ways: name-based and IP-based, although some control panels allow a mix of name-based and IP-based on the one server.IP-based
In IP-based virtual hosting, also called dedicated IP hosting, each virtual host has a different IP address. The web server is configured with multiple physical network interfaces, or virtual network interfaces on the same physical interface. The web server software uses the IP address the client connects to in order to determine which web site to show the user. The issue of IPv4 address exhaustion means that IP addresses are an increasingly scarce resource, so the primary justification for a site to use a dedicated IP is to be able to use its own SSL certificate rather than a shared certificate.Name-based
In name-based virtual hosting, also called shared IP hosting, the virtual hostsVirtual hosting
Virtual hosting is a method for hosting multiple domain names on a server using a single IP address. This allows one server to share its resources, such as memory and processor cycles, in order to use its resources more efficiently....
serve multiple hostnames on a single machine with a single IP address
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
. This is possible because when a web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
requests a resource from a web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
using HTTP/1.1 it includes the requested hostname as part of the request. The server uses this information to determine which web site to show the user.
Disadvantages
Name-based virtual hosts have some disadvantages:- They will not work with very old HTTP/1.0 browsers that do not send the hostname as part of requests. Since the "Host" header is mandatory in HTTP/1.1, which was issued in 1999 as RFC 2616, this is not a common issue.
- They do not properly support secure websites using HTTPSHttpsHypertext Transfer Protocol Secure is a combination of the Hypertext Transfer Protocol with SSL/TLS protocol to provide encrypted communication and secure identification of a network web server...
. All name-based virtual hosts using the same IP address must share the same digital certificate because the SSL/TLSTransport Layer SecurityTransport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet...
handshakeHandshakingIn information technology, telecommunications, and related fields, handshaking is an automated process of negotiation that dynamically sets parameters of a communications channel established between two entities before normal communication over the channel begins...
takes place before the hostname is sent to the server. Server Name IndicationServer Name IndicationServer Name Indication is a feature that extends the SSL and TLS protocols. To properly secure the communication between a client and a server, the client requests a digital certificate from the server; once the server sends the certificate, the client examines it, uses it to encrypt the...
is a potential solution but it is not yet widely implemented. - If the Domain Name SystemDomain name systemThe Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
is malfunctioning, or DNS changes haven't propagated to all ISPs' resolvers, it is not possible to fall back to using the IP address to contact the system. Some web hosting companies may offer an alternative access method likehttp://192.0.2.0/~virtualhostname http://virtualhostname.hostingsite.com/ - If file permissions have been improperly configured, then shared file systems might give other (compromised) users or processes system-wide access to these files.
See also
- Web hosting serviceWeb hosting serviceA web hosting service is a type of Internet hosting service that allows individuals and organizations to make their own website accessible via the World Wide Web. Web hosts are companies that provide space on a server they own or lease for use by their clients as well as providing Internet...
- Virtual Private ServerVirtual private serverVirtual private server is a term used by internet hosting services to refer to a virtual machine. The term is used for emphasizing that the virtual machine, although running in software on the same physical computer as other customers' virtual machines, is functionally equivalent to a separate...
- Dedicated hosting serviceDedicated hosting serviceA dedicated hosting service, dedicated server, or managed hosting service is a type of Internet hosting in which the client leases an entire server not shared with anyone. This is more flexible than shared hosting, as organizations have full control over the server, including choice of operating...
- Web serverWeb serverWeb server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
- Virtual machineVirtual machineA virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...