Return-Path: X-Original-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id BC59810D30 for ; Wed, 19 Nov 2014 05:51:34 +0000 (UTC) Received: (qmail 72020 invoked by uid 500); 19 Nov 2014 05:51:34 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 71962 invoked by uid 500); 19 Nov 2014 05:51:34 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 71859 invoked by uid 99); 19 Nov 2014 05:51:34 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 19 Nov 2014 05:51:34 +0000 Date: Wed, 19 Nov 2014 05:51:34 +0000 (UTC) From: "Lei (Eddy) Xu (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HDFS-3702) Add an option for NOT writing the blocks locally if there is a datanode on the same box as the client MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HDFS-3702?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Lei (Eddy) Xu updated HDFS-3702: -------------------------------- Assignee: Lei (Eddy) Xu Target Version/s: 2.7.0 Affects Version/s: (was: 2.0.0-alpha) (was: 1.0.3) 2.5.1 Status: Patch Available (was: Open) > Add an option for NOT writing the blocks locally if there is a datanode on the same box as the client > ----------------------------------------------------------------------------------------------------- > > Key: HDFS-3702 > URL: https://issues.apache.org/jira/browse/HDFS-3702 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client > Affects Versions: 2.5.1 > Reporter: Nicolas Liochon > Assignee: Lei (Eddy) Xu > Priority: Minor > Attachments: HDFS-3702.000.patch > > > This is useful for Write-Ahead-Logs: these files are writen for recovery only, and are not read when there are no failures. > Taking HBase as an example, these files will be read only if the process that wrote them (the 'HBase regionserver') dies. This will likely come from a hardware failure, hence the corresponding datanode will be dead as well. So we're writing 3 replicas, but in reality only 2 of them are really useful. -- This message was sent by Atlassian JIRA (v6.3.4#6332)