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 requ ...

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 Wikip ...

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 privatel ...

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 Coun ...

recently or frequently accessed

documents A document is a written, drawn, presented, or memorialized representation of thought, often the manifestation of non-fictional, as well as fictional, content. The word originates from the Latin ''Documentum'', which denotes a "teaching" or ...

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 In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...

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 JavaScri ...

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 Website, websites use JavaScript on the Client (computing), client side ...

) in order to reduce latency. *

prefetch Prefetching in computer science is a technique for speeding up fetch operations by beginning a fetch operation whose result is expected to be needed soon. Usually this is before it is ''known'' to be needed, so there is a risk of wasting time by p ...

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 l ...

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-dimension ...

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 commonl ...

. 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 Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telepho ...

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 Image, images, Sound recording, audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the medi ...

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 Streaming media is multimedia that is delivered and consumed in a continuous manner from a source, with little or no intermediate storage in network elements. ''Streaming'' refers to the delivery method of content, rather than the content i ...

, 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 co ...

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 Small and medium-sized enterprises (SMEs) or small and medium-sized businesses (SMBs) are businesses whose personnel and revenue numbers fall below certain limits. The abbreviation "SME" is used by international organizations such as the World Ban ...

List

America Online AOL (stylized as Aol., formerly a company known as AOL Inc. and originally known as America Online) is an American web portal and online service provider based in New York City. It is a brand marketed by the current incarnation of Yahoo (2017� ...

Netscape Netscape Communications Corporation (originally Mosaic Communications Corporation) was an American independent computer services company with headquarters in Mountain View, California and then Dulles, Virginia. Its Netscape web browser was on ...

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 cont ...

(discontinued) * Heigh Speed (discontinued) *

NetJet NetJet was the first commercially available web accelerator. The product was developed by Peak Technologies (changed in 1997 to PeakSoft Multinet Corp.) in 1996 and released in November 1996 at COMDEX in Las Vegas Nevada. NetJet was named a 'Best ...

(discontinued) * OnSpeed (discontinued) * Polipo (not maintained) *

Squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting ...

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 * Wingate ...

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 pict ...

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 In computer networks, a reverse proxy is the application that sits in front of back-end applications and forwards client (e.g. browser) requests to those applications. Reverse proxies help increase scalability, performance, resilience and securi ...

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 server ...

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 aiScaler Ltd. is a multinational software company founded in 2008. It develops application delivery controllers designed to allow dynamic web pages to scale content by intelligently caching frequently requested content. A number of websites i ...

* Apache

Traffic Server The Apache Traffic Server (ATS) is a modular, high-performance reverse proxy and forward proxy server, generally comparable to Nginx and Squid. It was created by Inktomi, and distributed as a commercial product called the Inktomi Traffic Ser ...

* 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) *

Varnish Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in vario ...

Client–server

There may be two sections to the proxy as well - a server portion sits in front of the

web server A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initi ...

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 on ...

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

References

External links

* {{DEFAULTSORT:Web Accelerator

Techniques

Web client accelerator

List

Web server accelerator

List

Client–server

See also

References

External links