A web accelerator is a

proxy server In computer networking, a proxy server is a server application that acts as an intermediary between a client requesting a resource and the server providing that resource. Instead of connecting directly to a server that can fulfill a reques ...

that reduces

website A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wi ...

access time. They can be a self-contained hardware appliance or installable software. Web accelerators may be installed on the client computer or mobile device, on

ISP An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise private ...

servers, on the server computer/network, or a combination. Accelerating delivery through compression requires some type of host-based server to collect, compress and then deliver content to a client computer.

Techniques

Web accelerators may use several techniques to achieve this reduction in access time: They may: *

cache Cache, caching, or caché may refer to: Places United States * Cache, Idaho, an unincorporated community * Cache, Illinois, an unincorporated community * Cache, Oklahoma, a city in Comanche County * Cache, Utah, Cache County, Utah * Cache County ...

recently or frequently accessed documents so they may be sent to the

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuabl ...

with less latency or at a faster transfer rate than the remote

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

could. *freshen objects in the cache ensuring that frequently accessed content is readily available for display. *preemptively resolve hostnames present in a document (

HTML The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaSc ...

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...

) in order to reduce latency. * prefetch documents that are likely to be accessed in the near future. *

compress compress is a Unix shell compression program based on the LZW compression algorithm. Compared to more modern compression utilities such as gzip and bzip2, compress performs faster and with less memory usage, at the cost of a significantly lo ...

documents to a smaller size, for example by reducing the quality of

images An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...

or by sending only what's changed since the document was last requested. * optimize the code from certain documents (such as

). *

filter Filter, filtering or filters may refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Filter (software), a computer program to process a data stream * Filter (video), a software component tha ...

out ads and other undesirable objects so they are not sent to the client at all. *maintain persistent TCP connections between the client and the proxy server. *improve the performance via protocol level accelerations, such as

TCP acceleration The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly ...

. These techniques align with best practices which are typically recommended to improve the performance of

web applications A web application (or web app) is application software that is accessed using a web browser. Web applications are delivered on the World Wide Web to users with an active network connection. History In earlier computing models like client-serve ...

Web client accelerator

Introduced in 2001-200

these applications generally serve to improve dial-up,

broadband In telecommunications, broadband is wide bandwidth data transmission which transports multiple signals at a wide range of frequencies and Internet traffic types, that enables messages to be sent simultaneously, used in fast internet connections. ...

and other connections from which users may not be getting the best speed. Many Dialup ISPs offer web accelerators as a part of their services. The pre-compression operates much more efficiently than the on-the-fly compression of V.44 modems. Typically, website text is compacted to 5%, thus increasing effective dialup throughput to approximately 1000 kbit/s, and JPEG/GIF/PNG images are lossy-compressed to 15–20%, increasing effective throughput to 300 kbit/s. The drawback of this approach is a loss in quality, where the graphics acquire

compression artifacts A compression artifact (or artefact) is a noticeable distortion of media (including images, audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the media's data so that it bec ...

taking on a blurry or colorless appearance. However, the transfer speed is dramatically improved. If desired, the user may choose to view uncompressed images instead, but at a much slower load rate. Web accelerators are typically designed for web browsing and, sometimes, for e-mailing and can not improve speeds of streaming, gaming, P2P downloads or many other Internet applications. However, there is substantial work being done on client-side Web Accelerators for Application Delivery Networks by several companies including Cisco Systems and F5 Networks as the demand for

SaaS Software as a service (SaaS ) is a software licensing and delivery model in which software is licensed on a subscription basis and is centrally hosted. SaaS is also known as "on-demand software" and Web-based/Web-hosted software. SaaS is con ...

and

PaaS Platform as a service (PaaS) or application platform as a service (aPaaS) or platform-based service is a category of cloud computing services that allows customers to provision, instantiate, run, and manage a modular bundle comprising a computing ...

look set to grow among small and medium enterprises.

List

* America Online * Netscape ISP *

Google Web Accelerator Google Web Accelerator was a web accelerator produced by Google. It used client software installed on the user's computer, as well as data caching on Google's servers, to speed up page load times by means of data compression, prefetching of con ...

(discontinued) * Heigh Speed (discontinued) * NetJet (discontinued) * OnSpeed (discontinued) * Polipo (not maintained) * Squid *

WinGate Wingate may refer to: Places New Zealand * Wingate, New Zealand, a suburb of Lower Hutt United Kingdom * Wingate, County Durham * Wingate Quarry, a Site of Special Scientific Interest in County Durham * Old Wingate, County Durham * Wingat ...

Ziproxy Ziproxy is a forwarding, non-caching, compressing, HTTP proxy server targeted for traffic optimization. The ziproxy software is regarded as lightweight in terms of memory and processing power consumption. This software works by recompressing pic ...

Web server accelerator

Other web accelerators are targeted at the web site or web application owners. This type of web accelerator is installed in front of web servers and application servers and use a variety of the above techniques to improve performance to all users accessing the accelerated web sites or web applications. Web server accelerators are sometimes referred to as reverse proxies or

Application Delivery Controller An application delivery controller (ADC) is a computer network device in a datacenter, often part of an application delivery network (ADN), that helps perform common tasks, such as those done by web accelerators to remove load from the web servers ...

s. This type of server side accelerator has the added benefit of off-loading transactions and connection managements from the web or applications servers and hence, reducing its CPU utilization and increasing web server or application scalability to handle more users with less bandwidth.

List

* aiScaler * Apache Traffic Server * CACHEbox *

nginx Nginx (pronounced "engine x" ) is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. The software was created by Igor Sysoev and publicly released in 2004. Nginx is free and open-source software ...

* Polipo (not maintained) * Squid * Varnish *

Client–server

There may be two sections to the proxy as well - a server portion sits in front of the web server and captures the input and output from the server and a client portion sits in front of the end-user's

web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used o ...

to capture the input and output from the browser. An example would be

Opera Turbo The history of the Opera (web browser), Opera web browser began in 1994 when it was started as a research project at Telenor, the largest Norwegian telecommunications company. In 1995, the project branched out into a separate company named Opera ...

References

External links

* {{DEFAULTSORT:Web Accelerator

Techniques

Web client accelerator

List

Web server accelerator

List

Client–server

See also

References

External links