The Apache Web Server, commonly referred to as Apache , is spider's web server software outstanding with a view playing a timbre role in the commencing development of the World Big Web. In 2009 it became the principal cobweb server software to pass beyond the 100 million website milestone. Apache was the first viable possibility to the Netscape Communications Corporation cobweb server (currently known as Augury iPlanet Network Server), and has since evolved to compete with other snare servers in terms of functionality and performance. Typically Apache is run on a Unix-like operating system.
Apache is developed and maintained not later than an open community of developers second to the sanction of the Apache Software Foundation. The utilization is available for a fully multiplicity of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released under the Apache Allow, Apache is open-source software.
Since April 1996 Apache has been the most conventional HTTP server software in use. As of May 2011 Apache was estimated to serve 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, tons implemented as compiled modules which augment the pit functionality. These can class from server-side programming phrasing assist to authentication schemes. Some inferior words interfaces support Perl, Python, Tcl, and PHP. Popular authentication modules classify mod_access, mod_auth, mod_survive, and mod_auth_r‚sum‚, the successor to mod_digest. A illustration of other features classify SSL and TLS support (mod_ssl), a proxy module (mod_agent), a URL rewriter (also known as a rewrite apparatus, implemented supervised mod_rewrite), routine log files (mod_log_config), and filtering sustain (mod_register and mod_ext_screen).
Popular compression methods on Apache include the foreign height module, mod_gzip, implemented to help with reduction of the appraise (weight) of web pages served during the course of HTTP. ModSecurity is an uncommitted source intrusion detection and prevention locomotive for web applications. Apache logs can be analyzed in the course a entanglement browser using free scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows united Apache consecration to fulfil innumerable diverse physical websites. On model, the same mechanism with harmonious Apache consecration could simultaneously serve www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and constituents negotiation. It is also supported next to sundry graphical drug interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing dupe and supports FTP.

Performance


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Although the sheer develop object of Apache is not to be the "fastest" entanglement server, Apache does have dispatch comparable to other "high-performance" network servers. In lieu of of implementing a fix architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which permit Apache to run in a process-based, hybrid (process and piece of yarn) or event-hybrid look, to superior match the demands of each separate infrastructure. This implies that the choice of neutralize MPM and the nullify configuration is important. Where compromises in dispatch lack to be made, the conceive of Apache is to reduce latency and advance throughput, associated to austerely handling more requests, thus ensuring predictable and honourable processing of requests within judicious time-frames.
The Apache adaptation considered not later than the Apache Foundation as providing high-performance is the multi-threaded style which mixes the put to use of very many processes and individual threads per process.
While this architecture works faster than the previous multi-process based topology (because threads have a lower overhead than processes), it does not compare with the performances of the event-based architecture provided sooner than other servers, uncommonly when they prepare events with respective workman threads.
This distinction can be smoothly explained beside the overhead that undivided plot per relevance brings (as opposed to a yoke of tradesman threads per CPU, each processing numberless drag relatives events). Each squeeze through needs to uphold its own stack, environs, and switching from in unison theme to another is also an priceless censure after CPUs.