Return-Path: X-Original-To: apmail-hbase-commits-archive@www.apache.org Delivered-To: apmail-hbase-commits-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 73C5A715B for ; Thu, 15 Dec 2011 03:56:32 +0000 (UTC) Received: (qmail 83196 invoked by uid 500); 15 Dec 2011 03:56:32 -0000 Delivered-To: apmail-hbase-commits-archive@hbase.apache.org Received: (qmail 83161 invoked by uid 500); 15 Dec 2011 03:56:30 -0000 Mailing-List: contact commits-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@hbase.apache.org Delivered-To: mailing list commits@hbase.apache.org Received: (qmail 83152 invoked by uid 99); 15 Dec 2011 03:56:27 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 15 Dec 2011 03:56:27 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=5.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.4] (HELO eris.apache.org) (140.211.11.4) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 15 Dec 2011 03:56:25 +0000 Received: from eris.apache.org (localhost [127.0.0.1]) by eris.apache.org (Postfix) with ESMTP id 55B4B23888CD for ; Thu, 15 Dec 2011 03:56:04 +0000 (UTC) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: svn commit: r1214614 - /hbase/trunk/src/docbkx/book.xml Date: Thu, 15 Dec 2011 03:56:04 -0000 To: commits@hbase.apache.org From: dmeil@apache.org X-Mailer: svnmailer-1.0.8-patched Message-Id: <20111215035604.55B4B23888CD@eris.apache.org> Author: dmeil Date: Thu Dec 15 03:56:03 2011 New Revision: 1214614 URL: http://svn.apache.org/viewvc?rev=1214614&view=rev Log: hbase-5036 book.xml architecture chapter minor mods regarding region-RS assignment Modified: hbase/trunk/src/docbkx/book.xml Modified: hbase/trunk/src/docbkx/book.xml URL: http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/book.xml?rev=1214614&r1=1214613&r2=1214614&view=diff ============================================================================== --- hbase/trunk/src/docbkx/book.xml (original) +++ hbase/trunk/src/docbkx/book.xml Thu Dec 15 03:56:03 2011 @@ -1319,6 +1319,8 @@ if (!b) { Startup Sequencing The META location is set in ROOT first. Then META is updated with server and startcode values. + For information on region-RegionServer assignment, see . + @@ -1724,46 +1726,35 @@ scan.setFilter(filter);
Startup When HBase starts regions are assigned as follows (short version): - - - The Master invokes the AssignmentManager upon startup. + The Master invokes the AssignmentManager upon startup. - - The AssignmentManager looks at the existing region assignments - in META. + The AssignmentManager looks at the existing region assignments in META. - - If the region assignment is still valid (i.e., if the RegionServer) is still online + If the region assignment is still valid (i.e., if the RegionServer) is still online then the assignment is kept. - - - If the assignment is invalid, then the LoadBalancerFactory is invoked to assign the - region. The DefaultLoadBalancer will randomly assign the region to a RegionServer. - + If the assignment is invalid, then the LoadBalancerFactory is invoked to assign the + region. The DefaultLoadBalancer will randomly assign the region to a RegionServer and + update META. - - + +
Failover When a RegionServer fails (short version): - - - The regions immediately become unavailable because the RegionServer is down. + The regions immediately become unavailable because the RegionServer is down. - - The Master will detect that the RegionServer has failed. + The Master will detect that the RegionServer has failed. - - The region assignments will be considered invalid and will be re-assigned just + The region assignments will be considered invalid and will be re-assigned just like the startup sequence. - +
@@ -1784,9 +1775,9 @@ scan.setFilter(filter); First replica is written to local node - Second replica to another node in same rack + Second replica is written to another node in same rack - Third replica to a node in another rack (if sufficient nodes) + Third replica is written to a node in another rack (if sufficient nodes) HBase eventually achieves locality for a region after a flush a compaction.