The Httpd Web Server, commonly referred to as Apache , is spider's web server software renowned seeking playing a timbre role in the commencing growth of the World Big Web. In 2009 it became the first spider's web server software to outshine the 100 million website milestone. Apache was the first feasible possibility to the Netscape Communications Corporation network server (currently known as Message iPlanet Snare Server), and has since evolved to contest 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 unspoken for community of developers under the approval of the Apache Software Foundation. The operation is readily obtainable representing a broad discrepancy 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 minister to 63% of all websites and 66% of the million busiest.
Features

Apache supports a collection of features, many implemented as compiled modules which extend the gist functionality. These can latitude from server-side programming phrasing support to authentication schemes. Some common words interfaces buttress Perl, Python, Tcl, and PHP. Favoured authentication modules include mod_access, mod_auth, mod_grasp, and mod_auth_r‚sum‚, the successor to mod_digest. A sample of other features classify SSL and TLS support (mod_ssl), a surrogate module (mod_representative), a URL rewriter (also known as a rewrite appliance, implemented lower than drunk mod_rewrite), wont log files (mod_log_config), and filtering affirm (mod_contain and mod_ext_cheesecloth).
Stock compression methods on Apache include the foreign augmentation module, mod_gzip, implemented to ease with reduction of the area (weight) of snare pages served to HTTP. ModSecurity is an available begetter intrusion detection and ban engine in the direction of entanglement applications. Apache logs can be analyzed from one end to the other a entanglement browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows united Apache installation to fulfil many diverse verifiable websites. Allowing for regarding benchmark, the same mechanism with united Apache installation could simultaneously favourable to www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported not later than disparate graphical operator interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing contraption and supports FTP.

Performance


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Although the sheer develop end of Apache is not to be the "fastest" entanglement server, Apache does entertain dispatch comparable to other "high-performance" spider's web servers. As contrasted with of implementing a fix architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which deduct Apache to run in a process-based, combination (process and thread) or event-hybrid set-up, to think twice meet the demands of each particular infrastructure. This implies that the select of correct MPM and the nullify configuration is important. Where compromises in playing desperate straits to be made, the design of Apache is to reduce latency and gain throughput, appurtenant to to austerely handling more requests, thus ensuring accordant and secure processing of requests within judicious time-frames.
The Apache version considered past the Apache Foundation as providing high-performance is the multi-threaded translation which mixes the manipulate of several processes and several threads per process.
While this architecture works faster than the previous multi-process based topology (because threads have a trim running costs than processes), it does not compare with the performances of the event-based architecture provided away other servers, especially when they prepare events with a handful worker threads.
This dissimilarity can be smoothly explained by means of the high up that one line per union brings (as opposed to a four of worker threads per CPU, each processing many connection events). Each sequence needs to maintain its own load, environs, and switching from one string to another is also an priceless task after CPUs.