The Httpd Web Server, commonly referred to as Apache , is snare server software renowned seeking playing a level place in the incipient broadening of the Set Wide Web. In 2009 it became the principal web server software to outshine the 100 million website milestone. Apache was the first practicable alternative to the Netscape Communications Corporation network server (currently known as Augury iPlanet Web Server), and has since evolved to challenge 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 during an unspoken for community of developers under the auspices of the Apache Software Foundation. The germaneness is elbow on 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 junior to the Apache Allow, Apache is open-source software.
Since April 1996 Apache has been the most fashionable HTTP server software in use. As of May 2011 Apache was estimated to be accurate 63% of all websites and 66% of the million busiest.
Features

Apache supports a variety of features, many implemented as compiled modules which proffer the insides functionality. These can range from server-side programming lingo assist to authentication schemes. Some inferior words interfaces support Perl, Python, Tcl, and PHP. Favoured authentication modules classify mod_access, mod_auth, mod_pr‚cis, and mod_auth_synopsis, the successor to mod_digest. A sample of other features include SSL and TLS supporter (mod_ssl), a surrogate module (mod_substitute), a URL rewriter (also known as a rewrite engine, implemented high mod_rewrite), wont log files (mod_log_config), and filtering support (mod_comprehend and mod_ext_eliminate).
Sought-after compression methods on Apache take in the foreign height module, mod_gzip, implemented to help with reduction of the size (weight) of snare pages served over with HTTP. ModSecurity is an uncommitted rise intrusion detection and ban apparatus in the direction of cobweb applications. Apache logs can be analyzed from one end to the other a web browser using delivered scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows everyone Apache consecration to one's duty multitudinous divers actual websites. On benchmark, joined gismo with harmonious Apache swearing-in could simultaneously favourable to www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable boob messages, DBMS-based authentication databases, and capacity negotiation. It is also supported by respective graphical operator interfaces (GUIs).
It supports password authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing tool and supports FTP.

Performance


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Although the sheer develop aspiration of Apache is not to be the "fastest" web server, Apache does take dispatch comparable to other "high-performance" network servers. Instead of implementing a only architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which permit Apache to leg it in a process-based, half-breed (deal with and thread) or event-hybrid mode, to superior match the demands of each particular infrastructure. This implies that the select of suitable MPM and the traditional configuration is important. Where compromises in doing need to be made, the lay out of Apache is to reduce latency and gain throughput, relative to obviously handling more requests, that reason ensuring predictable and honourable processing of requests within judicious time-frames.
The Apache adaptation considered not later than the Apache Base as providing high-performance is the multi-threaded style which mixes the put to use of diverse processes and various threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads suffer with a deign upper basic than processes), it does not match the performances of the event-based architecture provided via other servers, especially when they prepare events with a handful workman threads.
This distinction can be beyond explained by the aloft that one plot per union brings (as opposed to a twosome of worker threads per CPU, each processing profuse connection events). Each ease needs to contend its own load, habitat, and switching from inseparable theme to another is also an priceless stint in compensation CPUs.