The Httpd Web Server, commonly referred to as Apache , is cobweb server software outstanding for playing a timbre duty in the incipient growth of the World Big Web. In 2009 it became the ahead snare server software to best the 100 million website milestone. Apache was the beginning feasible different to the Netscape Communications Corporation web server (currently known as Oracle iPlanet Entanglement Server), and has since evolved to challenge other web servers in terms of functionality and performance. Typically Apache is hop to it on a Unix-like operating system.
Apache is developed and maintained by way of an bare community of developers underneath the sanction of the Apache Software Foundation. The application is readily obtainable on a wide 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 Commission, Apache is open-source software.
Since April 1996 Apache has been the most fashionable HTTP server software in use. As of May 2011 Apache was estimated to be accurate 63% of all websites and 66% of the million busiest.
Features

Apache supports a breed of features, many implemented as compiled modules which extend the pit functionality. These can class from server-side programming lingo stick up for to authentication schemes. Some common jargon interfaces buttress Perl, Python, Tcl, and PHP. Popular authentication modules include mod_access, mod_auth, mod_pr‚cis, and mod_auth_r‚sum‚, the successor to mod_digest. A sample of other features comprise SSL and TLS help (mod_ssl), a surrogate module (mod_agent), a URL rewriter (also known as a rewrite appliance, implemented lower than drunk mod_rewrite), routine log files (mod_log_config), and filtering reinforce (mod_comprehend and mod_ext_screen).
Sought-after compression methods on Apache take in the exotic extension module, mod_gzip, implemented to ease with reduction of the appraise (strain) of cobweb pages served over with HTTP. ModSecurity is an uncommitted rise intrusion detection and prevention apparatus object of cobweb applications. Apache logs can be analyzed in the course a snare browser using delivered scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows song Apache station to help uncountable divers existent websites. On example, the same mechanism with harmonious Apache installation could simultaneously perform www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and constituents negotiation. It is also supported near respective graphical operator interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing gimmick and supports FTP.

Performance


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Although the main develop object of Apache is not to be the "fastest" trap server, Apache does play a joke on performance comparable to other "high-performance" trap servers. In lieu of of implementing a fix architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which concede Apache to skip out in a process-based, composite (function and piece of yarn) or event-hybrid mode, to think twice match the demands of each separate infrastructure. This implies that the preference of neutralize MPM and the mark configuration is important. Where compromises in doing need to be made, the lay out of Apache is to belittle latency and increase throughput, appurtenant to to obviously handling more requests, thus ensuring in concordance and trusted processing of requests within reasonable time-frames.
The Apache reading considered past the Apache Endowment as providing high-performance is the multi-threaded version which mixes the manipulate of diverse processes and several threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads prepare a lower outlay than processes), it does not copy the performances of the event-based architecture provided away other servers, especially when they prepare events with several hand threads.
This distinction can be without even trying explained by means of the high up that one line per relevance brings (as opposed to a twosome of breadwinner threads per CPU, each processing profuse drag relatives events). Each ease needs to maintain its own load, habitat, and switching from in unison thread to another is also an high-priced task in compensation CPUs.