The Apache Web Server, commonly referred to as Apache , is web server software renowned seeking playing a pivotal place in the initial broadening of the Society Sizeable Web. In 2009 it became the ahead snare server software to surpass the 100 million website milestone. Apache was the beginning viable different to the Netscape Communications Corporation web server (currently known as Augury iPlanet Entanglement Server), and has since evolved to rival other web servers in terms of functionality and performance. Typically Apache is escape on a Unix-like operating system.
Apache is developed and maintained not later than an public community of developers impaired the protection of the Apache Software Foundation. The germaneness is readily obtainable instead of a fully multiplicity of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released impaired 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 accommodate 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, varied implemented as compiled modules which on the insides functionality. These can range from server-side programming communication authenticate to authentication schemes. Some conventional language interfaces support Perl, Python, Tcl, and PHP. Trendy authentication modules comprehend mod_access, mod_auth, mod_digest, and mod_auth_digest, the successor to mod_digest. A example of other features embrace SSL and TLS help (mod_ssl), a proxy module (mod_representative), a URL rewriter (also known as a rewrite appliance, implemented high mod_rewrite), custom log files (mod_log_config), and filtering support (mod_register and mod_ext_cheesecloth).
Popular compression methods on Apache include the external dimensions module, mod_gzip, implemented to servants with reduction of the appraise (strain) of cobweb pages served to HTTP. ModSecurity is an uncommitted begetter intrusion detection and prevention apparatus for net applications. Apache logs can be analyzed help of a snare browser using free scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows everyone Apache investiture to help multitudinous different physical websites. Allowing for regarding benchmark, joined machine with one Apache consecration could simultaneously be in the service of www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and content negotiation. It is also supported by disparate graphical consumer interfaces (GUIs).
It supports password authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing gimmick and supports FTP.

Performance


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Although the sheer layout goal of Apache is not to be the "fastest" spider's web server, Apache does play a joke on performance comparable to other "high-performance" trap servers. In lieu of of implementing a single architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which concede Apache to leg it in a process-based, composite (process and filament) or event-hybrid mode, to think twice twin the demands of each separate infrastructure. This implies that the preference of neutralize MPM and the mark configuration is important. Where compromises in performance need to be made, the conceive of Apache is to slash latency and increase throughput, appurtenant to to austerely handling more requests, consequently ensuring in concordance and reliable processing of requests within logical time-frames.
The Apache translation considered by the Apache Foundation as providing high-performance is the multi-threaded translation which mixes the use of very many processes and various threads per process.
While this architecture works faster than the previous multi-process based topology (because threads suffer with a move outlay than processes), it does not compare with the performances of the event-based architecture provided via other servers, unusually when they prepare events with a handful hand threads.
This distinction can be beyond explained by means of the overhead that a man plot per connection brings (as opposed to a yoke of wage-earner threads per CPU, each processing numberless correlation events). Each sequence needs to keep going its own load, environs, and switching from inseparable theme to another is also an high-priced assignment in search CPUs.