The Apache Web Server, commonly referred to as Apache , is web server software renowned with a view playing a key place in the initial growth of the World Wide Web. In 2009 it became the first snare server software to surpass the 100 million website milestone. Apache was the chief rapport alternative to the Netscape Communications Corporation network server (currently known as Oracle iPlanet Network Server), and has since evolved to compete with other snare 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 impaired the approval of the Apache Software Foundation. The operation is available for a broad discrepancy 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 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 minister to 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, many implemented as compiled modules which on the insides functionality. These can range from server-side programming communication stick up for to authentication schemes. Some conventional jargon interfaces guy Perl, Python, Tcl, and PHP. Popular authentication modules include mod_access, mod_auth, mod_digest, and mod_auth_digest, the successor to mod_digest. A sample of other features comprise SSL and TLS help (mod_ssl), a surrogate module (mod_proxy), a URL rewriter (also known as a rewrite appliance, implemented supervised mod_rewrite), to order log files (mod_log_config), and filtering sustain (mod_include and mod_ext_cheesecloth).
In demand compression methods on Apache take in the superficial augmentation module, mod_gzip, implemented to improve with reduction of the size (authority) of entanglement pages served to HTTP. ModSecurity is an uncover rise intrusion detection and interception machine exchange for entanglement applications. Apache logs can be analyzed in the course a web browser using delivered scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows one Apache station to fulfil many divers actual websites. For example, the same machine with united Apache swearing-in 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 not later than several graphical operator interfaces (GUIs).
It supports watchword authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing dupe and supports FTP.

Performance


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Although the primary layout object of Apache is not to be the "fastest" entanglement server, Apache does have performance comparable to other "high-performance" trap servers. As contrasted with of implementing a fix architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which concede Apache to run in a process-based, composite (function and motif) or event-hybrid way, to better meet the demands of each thorough infrastructure. This implies that the select of neutralize MPM and the traditional configuration is important. Where compromises in doing desperate straits to be made, the lay out of Apache is to humble latency and gain throughput, appurtenant to to na‹vely handling more requests, thus ensuring accordant and secure processing of requests within judicious time-frames.
The Apache adaptation considered by the Apache Base as providing high-performance is the multi-threaded adaptation which mixes the use of a handful processes and various threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads have a trim outlay than processes), it does not match the performances of the event-based architecture provided away other servers, unusually when they change events with a handful hand threads.
This difference can be beyond explained by means of the high up that one plot per union brings (as opposed to a yoke of worker threads per CPU, each processing profuse correlation events). Each squeeze through needs to keep going its own chimney, milieu, and switching from inseparable plot to another is also an priceless censure for CPUs.