The Httpd Web Server, commonly referred to as Apache , is snare server software renowned for playing a key place in the incipient growth of the Set Big Web. In 2009 it became the first spider's web server software to surpass the 100 million website milestone. Apache was the beginning feasible selection to the Netscape Communications Corporation trap server (currently known as Oracle iPlanet Entanglement Server), and has since evolved to rival other trap servers in terms of functionality and performance. Typically Apache is hop to it on a Unix-like operating system.
Apache is developed and maintained by way of an bare community of developers second to the approval of the Apache Software Foundation. The operation is elbow on a broad 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 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 accommodate 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, many implemented as compiled modules which extend the core functionality. These can latitude from server-side programming phrasing support to authentication schemes. Some community words interfaces suffer Perl, Python, Tcl, and PHP. In demand authentication modules include mod_access, mod_auth, mod_pr‚cis, and mod_auth_r‚sum‚, the successor to mod_digest. A example of other features embrace SSL and TLS stick (mod_ssl), a surrogate module (mod_substitute), a URL rewriter (also known as a rewrite locomotive, implemented lower than drunk mod_rewrite), routine log files (mod_log_config), and filtering sustain (mod_contain and mod_ext_cheesecloth).
Stock compression methods on Apache take in the superficial extension module, mod_gzip, implemented to servants with reduction of the size (ballast) of entanglement pages served to HTTP. ModSecurity is an open begetter intrusion detection and prevention machine object of cobweb applications. Apache logs can be analyzed through a cobweb browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows united Apache consecration to one's duty many diverse physical websites. Through despite example, joined gizmo with one Apache swearing-in could simultaneously favourable to www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable boob messages, DBMS-based authentication databases, and capacity negotiation. It is also supported by disparate graphical consumer interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing tool and supports FTP.

Exhibit


This portion does not cite any references or sources. Suit help improve this division by adding citations to secure sources. Unsourced figures may be challenged and removed. (October 2009)
Although the primary design goal of Apache is not to be the "fastest" entanglement server, Apache does have playing comparable to other "high-performance" web servers. As contrasted with of implementing a only architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which concede Apache to leg it in a process-based, hybrid (function and piece of yarn) or event-hybrid set-up, to excel meet the demands of each separate infrastructure. This implies that the choice of suitable MPM and the nullify configuration is important. Where compromises in dispatch desperate straits to be made, the conceive of Apache is to belittle latency and advance throughput, appurtenant to to obviously handling more requests, consequently ensuring predictable and honourable processing of requests within reasonable time-frames.
The Apache adaptation considered by means of the Apache Endowment as providing high-performance is the multi-threaded version which mixes the use 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 trim running costs than processes), it does not accord the performances of the event-based architecture provided by other servers, uncommonly when they prepare events with a variety of wage-earner threads.
This difference can be easily explained by means of the overhead that a man plot per relevance brings (as opposed to a couple of breadwinner threads per CPU, each processing numberless interplay events). Each ease needs to uphold its own load, milieu, and switching from one plot to another is also an valuable censure for CPUs.