The Apache HTTP Server, commonly referred to as Apache , is web server software outstanding seeking playing a level duty in the introductory growth of the World Wide Web. In 2009 it became the beginning spider's web server software to outshine the 100 million website milestone. Apache was the beginning rapport possibility to the Netscape Communications Corporation network server (currently known as Message iPlanet Network Server), and has since evolved to compete with other web 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 bare community of developers second to the protection of the Apache Software Foundation. The germaneness is available instead of a broad selection 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 conventional HTTP server software in use. As of May 2011 Apache was estimated to be accurate 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, divers implemented as compiled modules which augment the pit functionality. These can choice from server-side programming phrasing stick up for to authentication schemes. Some community lingua franca interfaces support Perl, Python, Tcl, and PHP. In demand authentication modules classify mod_access, mod_auth, mod_pr‚cis, and mod_auth_synopsis, the successor to mod_digest. A illustration of other features include SSL and TLS help (mod_ssl), a factor module (mod_agent), a URL rewriter (also known as a rewrite apparatus, implemented lower than drunk mod_rewrite), wont log files (mod_log_config), and filtering reinforce (mod_contain and mod_ext_screen).
In demand compression methods on Apache include the external height module, mod_gzip, implemented to improve with reduction of the size (ballast) of web pages served over HTTP. ModSecurity is an uncommitted rise intrusion detection and ban locomotive for net applications. Apache logs can be analyzed through a web browser using delivered scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows united Apache consecration to serve many diverse existent websites. For example, one gizmo with one Apache swearing-in could simultaneously serve www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable slip-up messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported near respective graphical operator interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing dupe and supports FTP.

Performance


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Although the foremost develop goal of Apache is not to be the "fastest" entanglement server, Apache does play a joke on fulfilment comparable to other "high-performance" network servers. Instead of implementing a fix architecture, Apache provides a breed of MultiProcessing Modules (MPMs) which permit Apache to hump it in a process-based, half-breed (deal with and thread) or event-hybrid mode, to think twice match the demands of each thorough infrastructure. This implies that the realm of possibilities of chasten MPM and the correct configuration is important. Where compromises in dispatch desperate straits to be made, the design of Apache is to belittle latency and gain throughput, associated to obviously handling more requests, in which case ensuring in concordance and trusted processing of requests within tenable time-frames.
The Apache reading considered past the Apache Base as providing high-performance is the multi-threaded adaptation which mixes the utilize consume of diverse 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 copy the performances of the event-based architecture provided away other servers, uncommonly when they change events with a variety of worker threads.
This difference can be easily explained by means of the aloft that undivided filament per connection brings (as opposed to a couple of worker threads per CPU, each processing profuse drag relatives events). Each ease needs to maintain its own clamp, habitat, and switching from inseparable thread to another is also an priceless stint in compensation CPUs.