Web accelerator: Difference between revisions

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{{Short description|Proxy server reducing website access time}}

A '''web accelerator''' is a [[proxy server]] that reduces [[web site]] [[access time]]s. Web accelerators may use several techniques to achieve this reduction:

{{More footnotes needed|date=November 2023}}

*They may [[web cache|cache]] recently or frequently accessed [[electronic document|documents]] so they may be sent to the [[client (computing)|client]] with less [[latency]] or at a faster [[transfer rate]] than the remote [[server (computing)|server]] could.

A '''web accelerator''' is a [[proxy server]] that reduces [[web sitewebsite]] [[access time]]s. WebThey acceleratorscan maybe usea severalself-contained techniqueshardware toappliance achieveor thisinstallable reduction:software.

*They may freshen objects in the cache ensuring that frequently accessed content is readily available for display.

*They may [[link prefetching|prefetch]] documents that are likely to be accessed in the near future.

*They may [[data compression|compress]] documents to a smaller size, for example by reducing the quality of [[digital image|images]] or by sending only what's changed since the document was last requested.

*They may [[filter (software)|filter]] out ads and other undesirable objects so they are not sent to the client at all.

*They may maintain persistent [[Transmission Control Protocol|TCP]] connections between the client and the proxy server.

Web accelerators may be installed on the client (browsing) computer or mobile device, on ISP[[Internet hostedservice provider|ISP]] servers, on the server computer/network, or botha combination. Accelerating delivery through compression requires some type of host -based server to collect, compress and then deliver content to a client computer.

==Techniques==

As of June 2005, these applications generally serve to improve [[dial-up]] and other low speed connections. Many users can achieve a 2 to 3 times speed increase in average browsing experience, while some report a 5 to 10 times speed increases for specific web pages.

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

They may:

[[Google]]'s [[Google Web Accelerator|Web Accelerator]] has attempted to improve [[broadband]] access to the sites. Moreover, they are designed for web browsing and, sometimes, for e-mailing and can not improve speeds of [[Streaming media|streaming]], gaming, P2P downloads or many other Internet applications. Many ISPs offer web accelerators as a part of their dial up service.

*They may [[web cache|cache]] recently or frequently accessed [[electronic document|documents]] so they may be sent to the [[client (computing)|client]] with less [[Latency (engineering)|latency]] or at a faster [[transfer rate]] than the remote [[server (computing)|server]] could.

*They may freshen objects in the cache ensuring that frequently accessed content is readily available for display.

*preemptively [[Domain name system|resolve hostnames]] present in a document ([[HTML]] or [[JavaScript]]) in order to reduce latency.

*They may [[link prefetching|prefetch]] documents that are likely to be accessed in the near future.

*They may [[data compression|compress]] documents to a smaller size, for example by reducing the quality of [[digital image|images]] or by sending only what's changed since the document was last requested.

*[[Optimization (computer science)|optimize]] the code<ref>{{cite web | url=https://page-audit.ru/wiki/Performance | title=Web page optimize | author=E. Geverin | work=Book }}</ref> from certain documents (such as [[HTML]] or [[JavaScript]]).

*They may [[filter (software)|filter]] out ads and other undesirable objects so they are not sent to the client at all.

*They may maintain persistent [[Transmission Control Protocol|TCP]] connections between the client and the proxy server.

*improve the performance via protocol level accelerations, such as [[TCP acceleration]].

These techniques align with best practices which are typically recommended to improve the performance of [[web applications]].<ref>{{cite web | url=http://docforge.com/wiki/Web_application#Performance | title=Web application | author=Multiple (wiki) | work=Docforge | access-date=2012-12-13 }}</ref>

Some web accelerators have been very controversial pieces of software. Critics claim that prefetching HTML page links slows the internet backbone. Others suggest that the accelerators overload web servers with prefetching and cache freshening behaviors.

==Web client accelerator==

===References and external links===

Introduced in 2001-2002 [https://www.wsj.com/articles/SB106012229328087800], these applications generally serve to improve [[dial-up]], [[broadband]] 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&nbsp;kbit/s, and JPEG/GIF/PNG images are lossy-compressed to 15–20%, increasing effective throughput to 300&nbsp;kbit/s.

*[http://www.monkeybrains.net/support/proxy.html#HERE Open Source Free Setup for your ISP] (apache sample config file)

*[http://www.arteraturbo.com/ Artera Turbo Web Accelerator]

*[http://www.ictcompress.com/ AcceleNet Web Accelerator]

*[http://www.propel.com/ Propel Internet & Email Accelerator]

*[http://www.proxyconn.com/ Proxyconn Web Accelerator]

*[http://webaccelerator.google.com/index.html Google Web Accelerator]

*[http://www.toonel.net/ Toonel] (Windows, Mac OS, Linux, Symbian UIQ, Windows Mobile)

*[http://www.onspeed.com/ Onspeed Web Accelerator]

*[http://www.opera.com/products/mobile/accelerator/ Opera Mobile Accelerator] (discontinued)

*[http://www.safersurf.com/ SaferSurf] (.de)

*[http://toptimizer.net.ru/ Traffic Optimizer] (.ru)

The drawback of this approach is a loss in quality, where the graphics acquire [[compression artifacts]] 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.

{{compu-network-stub}}

Web accelerators are typically designed for web browsing and, sometimes, for e-mailing and can not improve speeds of [[streaming media|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 [[software as a service|SaaS]] and [[PaaS]] look set to grow among [[small and medium enterprises]].

===List===

* [[America Online]]

* [[Netscape]] ISP

* [[Google Web Accelerator]] (discontinued)

* Heigh Speed (discontinued){{Citation needed|date=April 2022}}

* [[NetJet]] (discontinued)

* [[OnSpeed]] (discontinued)

* [[Polipo]] (not maintained)

* [[Squid (software)|Squid]]

* [[WinGate]]

* [[Ziproxy]]

* [[Varnish (software)|Varnish]]

==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 proxy|reverse proxies]] or [[Application Delivery Controller]]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]]

* [[Apache HTTP Server]]

* [[ApplianSys#CACHEbox|CACHEbox]]

* [[Caddy (web server)|Caddy]]

* [[lighttpd]]

* [[nginx]]

* [[Polipo]] (not maintained)

* [[Squid (software)|Squid]]

* [[Varnish (software)|Varnish]]

* [[Ziproxy]]

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

==See also==

* [[Content delivery network]]

* [[InterPlanetary File System]] - makes web accelerators redundant

==References==

<references/>

[[Category:Web accelerators| ]]