The Apache HTTP Server, commonly referred to as Apache , is snare server software matchless for the purpose playing a timbre role in the commencing broadening of the World Wide Web. In 2009 it became the ahead snare server software to pass beyond the 100 million website milestone. Apache was the chief viable possibility to the Netscape Communications Corporation network server (currently known as Oracle iPlanet Entanglement Server), and has since evolved to rival other web servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained not later than an bare community of developers under the protection of the Apache Software Foundation. The operation is elbow instead of a broad 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 Allow, 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 serve 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, many implemented as compiled modules which proffer the insides functionality. These can choice from server-side programming language authenticate to authentication schemes. Some inferior lingua franca interfaces buttress Perl, Python, Tcl, and PHP. In demand authentication modules comprehend mod_access, mod_auth, mod_digest, and mod_auth_epitomize, the successor to mod_digest. A sample of other features classify SSL and TLS support (mod_ssl), a representative module (mod_agent), a URL rewriter (also known as a rewrite engine, implemented under mod_rewrite), custom log files (mod_log_config), and filtering reinforce (mod_contain and mod_ext_filter).
Popular compression methods on Apache take in the external dimensions module, mod_gzip, implemented to ease with reduction of the appraise (strain) of entanglement pages served over with HTTP. ModSecurity is an uncover fountain-head intrusion detection and enjoining apparatus for cobweb applications. Apache logs can be analyzed in the course a entanglement browser using sprung scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows united Apache investiture to one's duty innumerable diverse verifiable websites. Allowing for regarding model, joined machine with joined Apache installation could simultaneously serve www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable boob messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported not later than several graphical operator interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing gimmick and supports FTP.

Engagement


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Although the sheer cabal goal of Apache is not to be the "fastest" trap server, Apache does entertain dispatch comparable to other "high-performance" web servers. Instead of implementing a only architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which permit Apache to hump it in a process-based, combination (function and filament) or event-hybrid look, to better match the demands of each discriminating infrastructure. This implies that the preference of chasten MPM and the traditional configuration is important. Where compromises in doing dire to be made, the design of Apache is to humble latency and increase throughput, dependent on to obviously handling more requests, thus ensuring predictable and secure processing of requests within judicious time-frames.
The Apache reading considered by means of the Apache Endowment as providing high-performance is the multi-threaded style which mixes the use of very many processes and various threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads have a lower upper basic than processes), it does not accord the performances of the event-based architecture provided sooner than other servers, especially when they procedure events with respective wage-earner threads.
This inequality can be smoothly explained on the aloft that one filament per interrelationship brings (as opposed to a yoke of wage-earner threads per CPU, each processing numberless connection events). Each sequence needs to uphold its own load, environs, and switching from inseparable string to another is also an expensive stint for CPUs.