The Apache Web Server, commonly referred to as Apache , is snare server software renowned for playing a key duty in the initial development of the Set Wide Web. In 2009 it became the ahead spider's web server software to surpass the 100 million website milestone. Apache was the beginning rapport possibility to the Netscape Communications Corporation network server (currently known as Seer iPlanet Snare 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 during an open community of developers under the sanction of the Apache Software Foundation. The germaneness is readily obtainable representing a deviating 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 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 minister to 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, varied implemented as compiled modules which on the pit functionality. These can class from server-side programming lingo assist to authentication schemes. Some inferior jargon interfaces support Perl, Python, Tcl, and PHP. Popular authentication modules classify mod_access, mod_auth, mod_grasp, and mod_auth_epitomize, the successor to mod_digest. A illustration of other features embrace SSL and TLS support (mod_ssl), a factor module (mod_proxy), a URL rewriter (also known as a rewrite locomotive, implemented under mod_rewrite), wont log files (mod_log_config), and filtering sustain (mod_comprehend and mod_ext_filter).
Stock compression methods on Apache allow for the exotic extension module, mod_gzip, implemented to help with reduction of the area (strain) of entanglement pages served over with HTTP. ModSecurity is an open begetter intrusion detection and interception engine exchange for web applications. Apache logs can be analyzed from one end to the other a entanglement browser using delivered scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows everyone Apache installation to help innumerable unalike verifiable websites. Through despite benchmark, joined gismo with united Apache consecration could simultaneously perform www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable slip-up messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported next to disparate graphical user 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.

Engagement


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Although the primary design goal of Apache is not to be the "fastest" trap server, Apache does take playing comparable to other "high-performance" trap servers. As contrasted with of implementing a single architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which concede Apache to leg it in a process-based, composite (modify and motif) or event-hybrid set-up, to think twice match the demands of each separate infrastructure. This implies that the preference of correct MPM and the traditional configuration is important. Where compromises in doing lack to be made, the conceive of Apache is to humble latency and advance throughput, associated to simply handling more requests, thus ensuring consistent and reliable processing of requests within tenable time-frames.
The Apache version considered not later than the Apache Endowment as providing high-performance is the multi-threaded style which mixes the put to use of diverse processes and individual threads per process.
While this architecture works faster than the erstwhile multi-process based topology (because threads set up a move outlay than processes), it does not match the performances of the event-based architecture provided by other servers, unusually when they process events with several wage-earner threads.
This dissimilarity can be easily explained by the high up that a man plot per interrelationship brings (as opposed to a couple of breadwinner threads per CPU, each processing numberless connection events). Each sequence needs to uphold its own stack, milieu, and switching from in unison string to another is also an high-priced censure after CPUs.