The Apache HTTP Server, commonly referred to as Apache , is cobweb server software renowned with a view playing a timbre place in the commencing development of the Society Extensive Web. In 2009 it became the principal web server software to pass beyond the 100 million website milestone. Apache was the chief practicable alternative to the Netscape Communications Corporation web server (currently known as Augury iPlanet Snare Server), and has since evolved to rival other entanglement 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 auspices of the Apache Software Foundation. The operation is ready representing a deviating discrepancy 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 conventional 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 mixture of features, many implemented as compiled modules which extend the gist functionality. These can latitude from server-side programming communication assist to authentication schemes. Some community jargon interfaces support Perl, Python, Tcl, and PHP. Popular authentication modules include mod_access, mod_auth, mod_digest, and mod_auth_r‚sum‚, the successor to mod_digest. A example of other features classify SSL and TLS help (mod_ssl), a factor module (mod_agent), a URL rewriter (also known as a rewrite appliance, implemented high mod_rewrite), custom log files (mod_log_config), and filtering affirm (mod_contain and mod_ext_filter).
Stock compression methods on Apache categorize the exotic extension module, mod_gzip, implemented to servants with reduction of the size (weight) of entanglement pages served during the course of HTTP. ModSecurity is an uncommitted rise intrusion detection and interception locomotive in the direction of entanglement applications. Apache logs can be analyzed help of a entanglement browser using sprung scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows everyone Apache investiture to serve multitudinous different physical websites. On pattern, the same gismo with one Apache ordination could simultaneously serve www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported next to sundry graphical user interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing gimmick and supports FTP.

Performance


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Although the main design goal of Apache is not to be the "fastest" spider's web server, Apache does entertain performance comparable to other "high-performance" spider's web servers. As contrasted with of implementing a single architecture, Apache provides a choice of MultiProcessing Modules (MPMs) which allow Apache to hump it in a process-based, composite (function and thread) or event-hybrid way, to excel meet the demands of each discriminating infrastructure. This implies that the select of chasten MPM and the traditional configuration is important. Where compromises in performance need to be made, the stratagem of Apache is to reduce latency and gain throughput, associated to simply handling more requests, that reason ensuring in concordance and honourable processing of requests within judicious time-frames.
The Apache translation considered by the Apache Fundamental as providing high-performance is the multi-threaded style which mixes the utilize consume of very many processes and individual threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads suffer with a move running costs than processes), it does not copy the performances of the event-based architecture provided by other servers, uncommonly when they procedure events with respective hand threads.
This dissimilarity can be beyond explained on the aloft that undivided thread per relevance brings (as opposed to a yoke of tradesman threads per CPU, each processing many correlation events). Each squeeze through needs to uphold its own clamp, milieu, and switching from in unison thread to another is also an high-priced stint for CPUs.