The Apache Web Server, commonly referred to as Apache , is spider's web server software outstanding for the purpose playing a timbre role in the initial success of the World Wide Web. In 2009 it became the principal cobweb server software to pass beyond the 100 million website milestone. Apache was the chief viable selection to the Netscape Communications Corporation cobweb server (currently known as Message iPlanet Snare Server), and has since evolved to challenge 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 underneath the protection of the Apache Software Foundation. The operation is available 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 under the Apache License, 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 breed of features, tons implemented as compiled modules which on the insides functionality. These can class from server-side programming communication support to authentication schemes. Some conventional jargon interfaces support Perl, Python, Tcl, and PHP. In demand authentication modules classify mod_access, mod_auth, mod_grasp, and mod_auth_epitomize, the successor to mod_digest. A representation of other features classify SSL and TLS supporter (mod_ssl), a representative module (mod_agent), a URL rewriter (also known as a rewrite locomotive, implemented under mod_rewrite), to order log files (mod_log_config), and filtering sustain (mod_register and mod_ext_eliminate).
Stock compression methods on Apache categorize the exotic dimensions module, mod_gzip, implemented to servants with reduction of the area (weight) of snare pages served to HTTP. ModSecurity is an uncommitted fountain-head intrusion detection and enjoining engine exchange for entanglement applications. Apache logs can be analyzed through a entanglement browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows everyone Apache consecration to help multitudinous different existent websites. On example, the same gismo with united Apache consecration could simultaneously serve www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and capacity negotiation. It is also supported next to sundry graphical operator interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing tool and supports FTP.

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Although the sheer design end of Apache is not to be the "fastest" spider's web server, Apache does have playing comparable to other "high-performance" spider's web servers. Instead of implementing a only architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which permit Apache to skip out in a process-based, half-breed (function and thread) or event-hybrid mode, to excel blend the demands of each thorough infrastructure. This implies that the preference of suitable MPM and the traditional configuration is important. Where compromises in performance need to be made, the conceive of Apache is to humble latency and augment throughput, appurtenant to to obviously handling more requests, thus ensuring consistent and secure processing of requests within judicious time-frames.
The Apache reading considered by means of the Apache Base as providing high-performance is the multi-threaded translation which mixes the use of diverse processes and individual threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads set up a lower upper basic than processes), it does not compare with the performances of the event-based architecture provided via other servers, especially when they change events with a variety of hand threads.
This inequality can be easily explained by means of the high up that a man filament per connection brings (as opposed to a four of breadwinner threads per CPU, each processing many correlation events). Each squeeze through needs to maintain its own clamp, habitat, and switching from inseparable theme to another is also an valuable stint for CPUs.