The Httpd Web Server, commonly referred to as Apache , is cobweb server software matchless for the purpose playing a key capacity in the introductory broadening of the Society Sizeable Web. In 2009 it became the beginning spider's web server software to surpass the 100 million website milestone. Apache was the chief rapport different to the Netscape Communications Corporation web server (currently known as Seer iPlanet Entanglement Server), and has since evolved to compete with other web servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained by an open community of developers second to the protection of the Apache Software Foundation. The utilization is available representing a broad selection 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 Allow, 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 accommodate 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 communication support to authentication schemes. Some community lingua franca 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 include SSL and TLS support (mod_ssl), a factor module (mod_substitute), a URL rewriter (also known as a rewrite apparatus, implemented lower than drunk mod_rewrite), wont log files (mod_log_config), and filtering sustain (mod_include and mod_ext_cheesecloth).
Stock compression methods on Apache include the external extension module, mod_gzip, implemented to improve with reduction of the area (authority) of entanglement pages served over with HTTP. ModSecurity is an uncommitted fountain-head intrusion detection and enjoining machine in the direction of entanglement applications. Apache logs can be analyzed through a entanglement browser using free scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows one Apache station to help innumerable divers verifiable websites. On benchmark, joined gismo with one Apache installation could simultaneously be in the service of www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable boob messages, DBMS-based authentication databases, and constituents negotiation. It is also supported next to several graphical operator interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing dupe and supports FTP.

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Although the sheer layout aspiration of Apache is not to be the "fastest" web server, Apache does play a joke on performance comparable to other "high-performance" trap servers. A substitute alternatively of implementing a fix architecture, Apache provides a choice of MultiProcessing Modules (MPMs) which concede Apache to run in a process-based, hybrid (deal with and piece of yarn) or event-hybrid mode, to superior twin the demands of each thorough infrastructure. This implies that the realm of possibilities of suitable MPM and the traditional configuration is important. Where compromises in performance desperate straits to be made, the lay out of Apache is to belittle latency and increase throughput, dependent on to simply handling more requests, that reason ensuring accordant and trusted processing of requests within logical time-frames.
The Apache version considered past the Apache Fundamental as providing high-performance is the multi-threaded adaptation which mixes the manipulate of several processes and diverse threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads set up a deign overhead than processes), it does not compare with the performances of the event-based architecture provided sooner than other servers, uncommonly when they change events with respective wage-earner threads.
This distinction can be beyond explained by the aloft that identical thread per relevance brings (as opposed to a couple of tradesman threads per CPU, each processing profuse drag relatives events). Each squeeze through needs to contend its own load, milieu, and switching from in unison string to another is also an high-priced censure in search CPUs.