The Apache HTTP Server, commonly referred to as Apache , is spider's web server software outstanding for the purpose playing a key duty in the initial success of the World Sizeable Web. In 2009 it became the beginning snare server software to outshine the 100 million website milestone. Apache was the chief rapport different to the Netscape Communications Corporation web server (currently known as Seer iPlanet Web Server), and has since evolved to compete with other web servers in terms of functionality and performance. Typically Apache is hop to it on a Unix-like operating system.
Apache is developed and maintained not later than an public community of developers second to the auspices of the Apache Software Foundation. The germaneness is readily obtainable for 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 supervised the Apache Accredit, 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 accommodate 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, many implemented as compiled modules which on the pit functionality. These can range from server-side programming language assist to authentication schemes. Some community lingua franca interfaces buttress Perl, Python, Tcl, and PHP. Trendy authentication modules take in mod_access, mod_auth, mod_pr‚cis, and mod_auth_r‚sum‚, the successor to mod_digest. A representation of other features include SSL and TLS stick (mod_ssl), a surrogate module (mod_proxy), a URL rewriter (also known as a rewrite locomotive, implemented high mod_rewrite), custom log files (mod_log_config), and filtering affirm (mod_contain and mod_ext_cheesecloth).
Stock compression methods on Apache categorize the superficial extension module, mod_gzip, implemented to improve with reduction of the area (strain) of web pages served to HTTP. ModSecurity is an open rise intrusion detection and prevention engine exchange for web applications. Apache logs can be analyzed in the course a entanglement browser using delivered scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows united Apache station to fulfil innumerable unalike actual websites. On model, the same mechanism with joined Apache swearing-in could simultaneously be in the service of www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable boob messages, DBMS-based authentication databases, and content negotiation. It is also supported by several graphical user interfaces (GUIs).
It supports watchword 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 sheer design goal of Apache is not to be the "fastest" entanglement server, Apache does take fulfilment comparable to other "high-performance" network servers. A substitute alternatively of implementing a single architecture, Apache provides a breed of MultiProcessing Modules (MPMs) which allow Apache to run in a process-based, half-breed (process and piece of yarn) or event-hybrid look, to think twice match the demands of each particular infrastructure. This implies that the realm of possibilities of suitable MPM and the mark configuration is important. Where compromises in doing need to be made, the conceive of Apache is to humble latency and gain throughput, associated to austerely handling more requests, thus ensuring consistent and secure processing of requests within tenable time-frames.
The Apache translation considered by the Apache Foundation as providing high-performance is the multi-threaded translation which mixes the use of several processes and individual threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads set up a trim upper basic than processes), it does not copy the performances of the event-based architecture provided away other servers, uniquely when they prepare events with respective workman threads.
This dissimilarity can be without even trying explained on the aloft that undivided filament per union brings (as opposed to a yoke of worker threads per CPU, each processing numberless connection events). Each sequence needs to uphold its own load, milieu, and switching from inseparable theme to another is also an valuable assignment in compensation CPUs.