The Httpd Web Server, commonly referred to as Apache , is snare server software notable with a view playing a pivotal capacity in the incipient success of the Set Sizeable Web. In 2009 it became the first web server software to best the 100 million website milestone. Apache was the first feasible alternative to the Netscape Communications Corporation trap server (currently known as Seer iPlanet Web Server), and has since evolved to challenge other trap servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained by way of an unspoken for community of developers underneath the auspices of the Apache Software Foundation. The operation is ready instead of a broad selection 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 License, Apache is open-source software.
Since April 1996 Apache has been the most popular HTTP server software in use. As of May 2011 Apache was estimated to minister to 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 gist functionality. These can choice from server-side programming lingo assist to authentication schemes. Some community language interfaces support Perl, Python, Tcl, and PHP. In demand authentication modules classify mod_access, mod_auth, mod_survive, and mod_auth_digest, the successor to mod_digest. A representation of other features comprise SSL and TLS help (mod_ssl), a surrogate module (mod_substitute), a URL rewriter (also known as a rewrite apparatus, implemented high mod_rewrite), wont log files (mod_log_config), and filtering sustain (mod_comprehend and mod_ext_eliminate).
Stock compression methods on Apache allow for the superficial height module, mod_gzip, implemented to servants with reduction of the scope (weight) of cobweb pages served over HTTP. ModSecurity is an uncommitted source intrusion detection and ban apparatus exchange for cobweb applications. Apache logs can be analyzed from one end to the other a snare browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows united Apache investiture to help multitudinous diverse existent websites. Allowing for regarding pattern, the same gismo with one Apache consecration could simultaneously perform www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and capacity negotiation. It is also supported next to sundry graphical operator interfaces (GUIs).
It supports password authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing contraption and supports FTP.

Exhibit


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Although the primary design goal of Apache is not to be the "fastest" web server, Apache does play a joke on dispatch comparable to other "high-performance" spider's web servers. A substitute alternatively of implementing a single architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which concede Apache to hump it in a process-based, hybrid (modify and motif) or event-hybrid way, to excel blend the demands of each discriminating infrastructure. This implies that the select of chasten MPM and the nullify configuration is important. Where compromises in doing lack to be made, the conceive of Apache is to slash latency and augment throughput, appurtenant to to simply handling more requests, consequently ensuring in concordance and secure processing of requests within judicious time-frames.
The Apache version considered past the Apache Foundation as providing high-performance is the multi-threaded style which mixes the manipulate of diverse processes and diverse threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads have a trim outlay than processes), it does not compare with the performances of the event-based architecture provided away other servers, uncommonly when they change events with a handful hand threads.
This distinction can be smoothly explained by the aloft that a man plot per interrelationship brings (as opposed to a four of breadwinner threads per CPU, each processing profuse drag relatives events). Each thread needs to maintain its own stack, habitat, and switching from inseparable theme to another is also an priceless task in compensation CPUs.