The Httpd Web Server, commonly referred to as Apache , is web server software renowned for the purpose playing a timbre role in the introductory broadening of the World Wide Web. In 2009 it became the principal spider's web server software to pass beyond the 100 million website milestone. Apache was the beginning viable different to the Netscape Communications Corporation web server (currently known as Oracle iPlanet Entanglement Server), and has since evolved to challenge 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 underneath the approval of the Apache Software Foundation. The germaneness is readily obtainable representing a deviating discrepancy of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released supervised the Apache Commission, 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, tons implemented as compiled modules which on the pit functionality. These can range from server-side programming lingo support to authentication schemes. Some inferior language interfaces buttress Perl, Python, Tcl, and PHP. Favoured authentication modules classify mod_access, mod_auth, mod_digest, and mod_auth_synopsis, the successor to mod_digest. A sample of other features comprise SSL and TLS help (mod_ssl), a representative module (mod_proxy), a URL rewriter (also known as a rewrite locomotive, implemented supervised mod_rewrite), custom log files (mod_log_config), and filtering reinforce (mod_include and mod_ext_cheesecloth).
Popular compression methods on Apache include the exotic dimensions module, mod_gzip, implemented to ease with reduction of the area (ballast) of cobweb pages served to HTTP. ModSecurity is an uncover rise intrusion detection and ban locomotive exchange for net applications. Apache logs can be analyzed help of a cobweb browser using free scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows everyone Apache installation to one's duty uncountable different existent websites. For benchmark, a specific mechanism with harmonious Apache consecration could simultaneously favourable to www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported by several graphical operator interfaces (GUIs).
It supports password 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 main develop object of Apache is not to be the "fastest" entanglement server, Apache does have fulfilment comparable to other "high-performance" network servers. Instead of implementing a single architecture, Apache provides a choice of MultiProcessing Modules (MPMs) which allow Apache to leg it in a process-based, composite (deal with and motif) or event-hybrid set-up, to better blend the demands of each thorough infrastructure. This implies that the realm of possibilities of neutralize MPM and the traditional configuration is important. Where compromises in playing lack to be made, the lay out of Apache is to slash latency and advance throughput, appurtenant to to austerely handling more requests, in which case ensuring consistent and reliable processing of requests within tenable time-frames.
The Apache version considered by means of the Apache Endowment as providing high-performance is the multi-threaded style which mixes the utilize consume of a handful processes and individual threads per process.
While this architecture works faster than the previous multi-process based topology (because threads prepare a deign overhead than processes), it does not accord the performances of the event-based architecture provided sooner than other servers, especially when they process events with a variety of worker threads.
This difference can be easily explained by means of the high up that a man filament per connection brings (as opposed to a yoke of breadwinner threads per CPU, each processing numberless interplay events). Each squeeze through needs to maintain its own load, environment, and switching from joke string to another is also an priceless censure in search CPUs.