The Apache Web Server, commonly referred to as Apache , is cobweb server software renowned seeking playing a level role in the incipient development of the World Wide Web. In 2009 it became the beginning cobweb server software to pass beyond the 100 million website milestone. Apache was the beginning feasible alternative to the Netscape Communications Corporation network server (currently known as Augury iPlanet Network Server), and has since evolved to challenge other web servers in terms of functionality and performance. Typically Apache is escape on a Unix-like operating system.
Apache is developed and maintained not later than an public community of developers impaired the approval of the Apache Software Foundation. The germaneness is available for a deviating discrepancy of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released junior to the Apache Commission, Apache is open-source software.
Since April 1996 Apache has been the most popular 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 collection of features, varied implemented as compiled modules which on the pit functionality. These can latitude from server-side programming language support to authentication schemes. Some conventional language interfaces buttress Perl, Python, Tcl, and PHP. In demand authentication modules comprehend mod_access, mod_auth, mod_digest, and mod_auth_synopsis, the successor to mod_digest. A illustration of other features classify SSL and TLS help (mod_ssl), a surrogate module (mod_proxy), a URL rewriter (also known as a rewrite apparatus, implemented high mod_rewrite), routine log files (mod_log_config), and filtering sustain (mod_contain and mod_ext_filter).
Sought-after compression methods on Apache include the exotic extension module, mod_gzip, implemented to ease with reduction of the appraise (ballast) of web pages served over with HTTP. ModSecurity is an available fountain-head intrusion detection and prevention engine for net applications. Apache logs can be analyzed help of a cobweb browser using delivered scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows everyone Apache station to help innumerable divers physical websites. Through despite model, the same mechanism with joined Apache consecration could simultaneously serve www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported not later than several graphical drug interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search machine and an HTML authorizing gimmick and supports FTP.

Engagement


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Although the sheer cabal object of Apache is not to be the "fastest" web server, Apache does entertain performance comparable to other "high-performance" trap servers. In lieu of of implementing a only architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which allow Apache to skip out in a process-based, hybrid (modify and thread) or event-hybrid mode, to think twice match the demands of each discriminating infrastructure. This implies that the realm of possibilities of suitable MPM and the mark configuration is important. Where compromises in playing lack to be made, the lay out of Apache is to slash latency and gain throughput, appurtenant to to austerely handling more requests, thus ensuring accordant and honourable processing of requests within tenable time-frames.
The Apache translation considered by the Apache Foundation as providing high-performance is the multi-threaded version which mixes the put to use of diverse processes and diverse threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads set up a trim overhead than processes), it does not match the performances of the event-based architecture provided sooner than other servers, uniquely when they procedure events with respective hand threads.
This distinction can be easily explained by means of the high up that identical plot per union brings (as opposed to a couple of tradesman threads per CPU, each processing diverse drag relatives events). Each sequence needs to uphold its own chimney, milieu, and switching from joke thread to another is also an high-priced task after CPUs.