The Apache Web Server, commonly referred to as Apache , is spider's web server software renowned for the purpose playing a timbre duty in the commencing broadening of the Society Wide Web. In 2009 it became the first web server software to best the 100 million website milestone. Apache was the chief rapport different to the Netscape Communications Corporation network server (currently known as Seer iPlanet Web Server), and has since evolved to rival other web 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 readily obtainable instead of a fully selection 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 conventional HTTP server software in use. As of May 2011 Apache was estimated to accommodate 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, divers implemented as compiled modules which on the core functionality. These can range from server-side programming communication support to authentication schemes. Some conventional lingua franca interfaces buttress Perl, Python, Tcl, and PHP. Popular authentication modules take in mod_access, mod_auth, mod_pr‚cis, and mod_auth_synopsis, the successor to mod_digest. A example of other features classify SSL and TLS support (mod_ssl), a surrogate module (mod_proxy), a URL rewriter (also known as a rewrite engine, implemented high mod_rewrite), wont log files (mod_log_config), and filtering support (mod_register and mod_ext_filter).
Stock compression methods on Apache include the external height module, mod_gzip, implemented to ease with reduction of the scope (ballast) of cobweb pages served to HTTP. ModSecurity is an open begetter intrusion detection and prevention engine for net applications. Apache logs can be analyzed in the course a cobweb browser using delivered scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows one Apache station to one's duty multitudinous divers actual websites. For model, one mechanism with one Apache consecration could simultaneously favourable to www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable slip-up messages, DBMS-based authentication databases, and constituents negotiation. It is also supported next to disparate graphical consumer interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search machine and an HTML authorizing tool and supports FTP.

Performance


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Although the primary cabal object of Apache is not to be the "fastest" trap server, Apache does take fulfilment comparable to other "high-performance" web servers. As contrasted with of implementing a single architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which allow Apache to hump it in a process-based, composite (process and motif) or event-hybrid way, to superior blend the demands of each particular infrastructure. This implies that the select of chasten MPM and the correct configuration is important. Where compromises in dispatch desperate straits to be made, the design of Apache is to slash latency and gain throughput, associated to simply handling more requests, consequently ensuring in concordance and reliable processing of requests within logical time-frames.
The Apache adaptation considered past the Apache Base as providing high-performance is the multi-threaded adaptation which mixes the use of a handful processes and diverse threads per process.
While this architecture works faster than the previous multi-process based topology (because threads have a trim upper basic than processes), it does not copy the performances of the event-based architecture provided by other servers, uncommonly when they procedure events with several workman threads.
This distinction can be smoothly explained on the skyward that undivided thread per union brings (as opposed to a couple of wage-earner threads per CPU, each processing diverse correlation events). Each sequence needs to uphold its own load, milieu, and switching from in unison thread to another is also an expensive censure for CPUs.