The Slashdot effect is a particular example of how incoming links from a popular website can cause a smaller site to slow down or even temporarily close due to the increased traffic. The name comes from the huge influx of web traffic that often results from sites being mentioned on Slashdot, a popular technology news and information site. Typically, less robust sites are unable to cope with the huge increase in traffic and become unavailable – either their bandwidth is consumed or their servers fail to cope with the high strain.

Links from other popular websites can cause problems comparable to the Slashdot effect – see web traffic#Traffic overload.

=Cause=

Slashdot consists of brief submitted articles and a self-moderated discussion on each story. In response to the stories, large masses of readers tend to simultaneously rush to view referenced sites. The ensuing flood of page requests, known as a slashdotting, often exceeds the ability of the site to respond in a timely manner, rendering the site slashdotted and, for many visitors, unavailable for a time, occasionally exceeding the site s bandwidth limitations or causing servers to slow down. A [http://it.slashdot.org/comments.plsid=150104&cid=12584521 recent comment] in a Slashdot story summarizes the effect nicely: Slashdot is world famous. A roving random distributed denial of service attack before which web, network and systems administrators alike quake and have terrible nightmares about.

Slashdotted is sometimes abbreviated as /.ed in postings on the Slashdot site.

The Slashdot effect has also been seen on sites that are mocked on the Awful Link of the Day section of the popular humor website [http://www.somethingawful.com Something Awful], which ridicules sites, movies, video games, music bands, etc. that it considers bad or stupid. One affected site, a website devoted to anthropomorphic furry art, even closed down permanently because the influx of visitors from Something Awful, and the insulting and profane email messages that were sent en masse by SA readers to the administrator s inbox.

=Extent=

Major news sites or corporate websites are typically unaffected by the Slashdot effect because they have been engineered to serve large numbers of requests. Websites that usually fall victim are generally smaller sites either hosted on home servers, with many large images or movie files or with inefficiently written dynamic content (e.g. many database hits for every web hit even if all web hits are requesting the same page). These websites often become unavailable within just a few minutes of an article s posting on Slashdot, even before any comments have been posted. Occasionally, paying Slashdot subscribers, who have access to stories before non-paying users, have rendered a site unavailable even before the story is posted for the general userbase.

Few definitive numbers [http://ssadler.phy.bnl.gov/adler/SDE/SlashDotEffect.html][http://www.astro.princeton.edu/~mjuric/universe/slashdotting/] [http://ascii.pdp10.org/images.shtml#slashdotted] exist regarding the precise magnitude of the Slashdot effect, but estimates put the peak of the mass influx of page requests at anywhere from several hundred to several thousand hits per minute. The flood usually peaks when the article is at the top of Slashdot s front page and gradually subsides as the story is superseded by newer items. Traffic usually remains at elevated levels until the article is pushed off the front page, which can take from 12 to 18 hours after its initial posting. However, certain things get bogged down for longer time. This all depends on the number of people posting, and for how long the story stays interesting. The marriage proposal of Slashdot founder Rob Malda [http://slashdot.org/articles/02/02/14/143254.shtmltid=166] and the announcement of Windows 2000 and Windows NT 4 source code leaks [http://slashdot.org/article.plsid=04/02/12/2114228&tid=109] were a couple of the more active stories.

Some have recently commented that the slashdot effect has been diminishing. [http://www.businessweek.com/technology/content/mar2005/tc2005032_0932_tc119.htm]

==Communities==

When the targeted website has a internet community-based structure, the term can also refer to the secondary effect of having a large group of users suddenly setting up accounts and starting to participate in the community. While in some cases this has been considered a good thing, in others it is viewed with disdain by the prior members, as quite often the sheer number of new people brings a lot of the unwanted aspects of Slashdot along with it, such as incessant Internet troll, vandalism, and Newbie-like behavior (see Slashdot trolling phenomena).

=Assistance and prevention=

Slashdot does not mirror (computing) the sites it links to on its own servers nor does it endorse a third party solution. Slashdot, a commercial venture, makes its name by listing interesting web sites or news stories on its front page which are then consequently and routinely bombarded with more traffic than they were prepared for and, in some cases, more than they cared for.

The mirroring of content may constitute a breach of copyright, and in many cases, cause ad revenue to be lost for the site. The questionable legality of this practice is one of the primary reasons it has not been instituted. One may also argue that having to ask for permission to link to another page is against the spirit of the World Wide Web.

One tool commonly advocated to assist smaller sites in bearing the load of a Slashdot effect is the Coral Content Distribution Network P2P Web Cache [http://www.scs.cs.nyu.edu/coral/], designed at New York University. However, the Coral caching system does not rewrite intrasite links, nor does it rewrite image URL s, so a Coral-ized link from Slashdot will still usually deal a crushing blow to an unprepared server.

[http://www.mirrordot.org/ MirrorDot] and [http://www.networkmirror.com Network Mirror] are systems that automatically mirror any Slashdot-linked pages and ensure the content would remain available, even if the original site got clobbered - trying to solve the Slashdot effect.

After repeated incidents in which Mozilla Organization s Bugzilla bugtracker was taken down when Slashdot linked directly to bug entries, Bugzilla started blocking links from Slashdot. Clicking a hyperlink on Slashdot to Bugzilla now produces the error message Sorry, links to Bugzilla from Slashdot are disabled.

=External links=