The Apache Web Server, commonly referred to as Apache , is cobweb server software renowned with a view playing a level capacity in the introductory broadening of the World Wide Web. In 2009 it became the ahead web server software to pass beyond the 100 million website milestone. Apache was the chief viable selection to the Netscape Communications Corporation network server (currently known as Augury iPlanet Entanglement Server), and has since evolved to contest other snare servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained by way of an public community of developers under the auspices of the Apache Software Foundation. The germaneness is readily obtainable instead of a fully 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 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 variety of features, many implemented as compiled modules which extend the core functionality. These can range from server-side programming phrasing assist to authentication schemes. Some common lingua franca interfaces buttress Perl, Python, Tcl, and PHP. Popular authentication modules take in mod_access, mod_auth, mod_survive, and mod_auth_digest, the successor to mod_digest. A example of other features comprise SSL and TLS supporter (mod_ssl), a representative module (mod_representative), a URL rewriter (also known as a rewrite appliance, implemented high mod_rewrite), to order log files (mod_log_config), and filtering affirm (mod_comprehend and mod_ext_filter).
Stock compression methods on Apache categorize the foreign height module, mod_gzip, implemented to ease with reduction of the area (weight) of cobweb pages served during the course of HTTP. ModSecurity is an uncommitted source intrusion detection and enjoining locomotive exchange for cobweb applications. Apache logs can be analyzed in the course a web browser using free scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows united Apache station to fulfil innumerable unalike verifiable websites. For model, a specific gismo with one Apache swearing-in could simultaneously serve www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and constituents negotiation. It is also supported not later than disparate graphical operator interfaces (GUIs).
It supports watchword authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing tool and supports FTP.

Exhibit


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Although the main design end 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 individual architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which allow Apache to skip out in a process-based, hybrid (function and thread) or event-hybrid set-up, to think twice twin the demands of each thorough infrastructure. This implies that the choice of suitable MPM and the correct configuration is important. Where compromises in dispatch desperate straits to be made, the stratagem of Apache is to humble latency and advance throughput, dependent on to obviously handling more requests, thus ensuring predictable and trusted processing of requests within reasonable time-frames.
The Apache version considered by means of the Apache Base as providing high-performance is the multi-threaded version which mixes the use of a handful processes and individual threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads have a lower outlay than processes), it does not compare with the performances of the event-based architecture provided away other servers, uniquely when they prepare events with several workman threads.
This inequality can be beyond explained by the high up that a man line per interrelationship brings (as opposed to a twosome of wage-earner threads per CPU, each processing many drag relatives events). Each ease needs to maintain its own chimney, milieu, and switching from one thread to another is also an valuable censure after CPUs.