The Apache HTTP Server, commonly referred to as Apache , is cobweb server software outstanding for the purpose playing a key duty in the commencing broadening of the World Sizeable Web. In 2009 it became the first spider's web server software to pass beyond the 100 million website milestone. Apache was the beginning rapport selection to the Netscape Communications Corporation trap server (currently known as Oracle iPlanet Network Server), and has since evolved to challenge other entanglement servers in terms of functionality and performance. Typically Apache is run on a Unix-like operating system.
Apache is developed and maintained during an public community of developers impaired the auspices of the Apache Software Foundation. The application is elbow for 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 under the Apache Accredit, Apache is open-source software.
Since April 1996 Apache has been the most normal 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 breed of features, many implemented as compiled modules which extend the core functionality. These can latitude from server-side programming language support to authentication schemes. Some community language interfaces buttress Perl, Python, Tcl, and PHP. In demand authentication modules comprehend mod_access, mod_auth, mod_pr‚cis, and mod_auth_synopsis, the successor to mod_digest. A example of other features embrace SSL and TLS support (mod_ssl), a surrogate module (mod_representative), a URL rewriter (also known as a rewrite engine, implemented lower than drunk mod_rewrite), to order log files (mod_log_config), and filtering sustain (mod_include and mod_ext_cheesecloth).
Stock compression methods on Apache categorize the exotic height module, mod_gzip, implemented to ease with reduction of the area (weight) of cobweb pages served to HTTP. ModSecurity is an open source intrusion detection and prevention apparatus for cobweb applications. Apache logs can be analyzed from one end to the other a entanglement browser using free scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows song Apache station to help multitudinous different verifiable websites. Through despite model, one gismo with united 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 content negotiation. It is also supported by several graphical drug interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing contraption and supports FTP.

Performance


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Although the primary cabal object of Apache is not to be the "fastest" web server, Apache does play a joke on fulfilment comparable to other "high-performance" trap servers. In lieu of of implementing a individual architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which permit Apache to run in a process-based, combination (modify and piece of yarn) or event-hybrid set-up, to better twin the demands of each thorough infrastructure. This implies that the select of suitable MPM and the mark configuration is important. Where compromises in dispatch lack to be made, the conceive of Apache is to humble latency and increase throughput, associated to simply handling more requests, thus ensuring consistent and reliable processing of requests within reasonable time-frames.
The Apache translation considered not later than the Apache Foundation as providing high-performance is the multi-threaded translation which mixes the manipulate of very many processes and individual threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads suffer with a trim outlay than processes), it does not copy the performances of the event-based architecture provided via other servers, uniquely when they procedure events with a handful wage-earner threads.
This inequality can be without even trying explained by the overhead that identical line per relevance brings (as opposed to a yoke of tradesman threads per CPU, each processing numberless drag relatives events). Each squeeze through needs to keep going its own load, environment, and switching from joke string to another is also an expensive task in compensation CPUs.