Return-Path: Delivered-To: apmail-lucene-hadoop-commits-archive@locus.apache.org Received: (qmail 49941 invoked from network); 20 Jul 2007 03:13:56 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 20 Jul 2007 03:13:56 -0000 Received: (qmail 50123 invoked by uid 500); 20 Jul 2007 03:13:27 -0000 Delivered-To: apmail-lucene-hadoop-commits-archive@lucene.apache.org Received: (qmail 50104 invoked by uid 500); 20 Jul 2007 03:13:27 -0000 Mailing-List: contact hadoop-commits-help@lucene.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hadoop-dev@lucene.apache.org Delivered-To: mailing list hadoop-commits@lucene.apache.org Received: (qmail 50094 invoked by uid 99); 20 Jul 2007 03:13:27 -0000 Received: from herse.apache.org (HELO herse.apache.org) (140.211.11.133) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 19 Jul 2007 20:13:27 -0700 X-ASF-Spam-Status: No, hits=-100.0 required=10.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.130] (HELO eos.apache.org) (140.211.11.130) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 19 Jul 2007 20:13:24 -0700 Received: from eos.apache.org (localhost [127.0.0.1]) by eos.apache.org (Postfix) with ESMTP id 927315A250 for ; Fri, 20 Jul 2007 03:13:04 +0000 (GMT) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Apache Wiki To: hadoop-commits@lucene.apache.org Date: Fri, 20 Jul 2007 03:13:04 -0000 Message-ID: <20070720031304.13321.71174@eos.apache.org> Subject: [Lucene-hadoop Wiki] Update of "ImportantConcepts" by TedDunning X-Virus-Checked: Checked by ClamAV on apache.org Dear Wiki user, You have subscribed to a wiki page or wiki category on "Lucene-hadoop Wiki" for change notification. The following page has been changed by TedDunning: http://wiki.apache.org/lucene-hadoop/ImportantConcepts ------------------------------------------------------------------------------ Some notable terms that may confuse you: * Hadoop - Hadoop itself refers to the overall system that runs jobs, distributes tasks (pieces of these jobs) and stores data in a parallel and distributed fashion. + + * [:HadoopMapReduce:Map/reduce] - Is the style in which most programs running on Hadoop are written. In this style, input is broken in tiny pieces which are processed independently (the map part). The results of these independent processes are then collated into groups and processed as groups (the reduce part). Follow the link for a much more complete description. * Job - In hadoop, the combination of all of the jars and classes needed to run a map/reduce program is called a job. All of these components are themselves collected into a jar which is usually referred to as a job file. To execute a job, you normally will use the command: