The Httpd Web Server, commonly referred to as Apache , is web server software notable for the purpose playing a key duty in the commencing growth of the World Big Web. In 2009 it became the beginning spider's web server software to best the 100 million website milestone. Apache was the first rapport different to the Netscape Communications Corporation network server (currently known as Seer iPlanet Entanglement Server), and has since evolved to compete with other trap servers in terms of functionality and performance. Typically Apache is run on a Unix-like operating system.
Apache is developed and maintained by an unspoken for community of developers underneath the sanction of the Apache Software Foundation. The application is readily obtainable representing a wide variety 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 popular 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, many implemented as compiled modules which proffer the gist functionality. These can choice from server-side programming communication authenticate to authentication schemes. Some inferior lingua franca interfaces suffer Perl, Python, Tcl, and PHP. In demand authentication modules include mod_access, mod_auth, mod_grasp, and mod_auth_digest, the successor to mod_digest. A example of other features classify SSL and TLS help (mod_ssl), a representative module (mod_agent), a URL rewriter (also known as a rewrite engine, implemented supervised mod_rewrite), custom log files (mod_log_config), and filtering reinforce (mod_contain and mod_ext_eliminate).
In demand compression methods on Apache include the foreign dimensions module, mod_gzip, implemented to help with reduction of the size (weight) of cobweb pages served over HTTP. ModSecurity is an uncommitted fountain-head intrusion detection and ban engine for cobweb applications. Apache logs can be analyzed through a snare browser using free scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows song Apache consecration to serve multitudinous diverse verifiable websites. Through despite example, one machine with one Apache ordination could simultaneously perform www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and capacity negotiation. It is also supported next to respective graphical user interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing tool and supports FTP.

Engagement


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Although the primary develop object of Apache is not to be the "fastest" entanglement server, Apache does play a joke on fulfilment comparable to other "high-performance" trap 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, composite (process and piece of yarn) or event-hybrid way, to excel meet the demands of each discriminating infrastructure. This implies that the realm of possibilities of correct MPM and the traditional configuration is important. Where compromises in performance desperate straits to be made, the conceive of Apache is to humble latency and increase throughput, relative to na‹vely handling more requests, thus ensuring predictable and trusted processing of requests within logical time-frames.
The Apache reading considered by the Apache Endowment as providing high-performance is the multi-threaded style which mixes the manipulate of several processes and several threads per process.
While this architecture works faster than the erstwhile multi-process based topology (because threads set up a lower upper basic than processes), it does not accord the performances of the event-based architecture provided away other servers, uncommonly when they process events with a variety of worker threads.
This inequality can be beyond explained by means of the skyward that a man filament per interrelationship brings (as opposed to a yoke of tradesman threads per CPU, each processing profuse interplay events). Each squeeze through needs to keep going its own stack, environment, and switching from one plot to another is also an valuable stint in search CPUs.