Return-Path: X-Original-To: apmail-hbase-issues-archive@www.apache.org Delivered-To: apmail-hbase-issues-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 1FC3E10082 for ; Thu, 13 Jun 2013 05:34:29 +0000 (UTC) Received: (qmail 12414 invoked by uid 500); 13 Jun 2013 05:34:25 -0000 Delivered-To: apmail-hbase-issues-archive@hbase.apache.org Received: (qmail 11855 invoked by uid 500); 13 Jun 2013 05:34:22 -0000 Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list issues@hbase.apache.org Received: (qmail 11795 invoked by uid 99); 13 Jun 2013 05:34:20 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 13 Jun 2013 05:34:20 +0000 Date: Thu, 13 Jun 2013 05:34:20 +0000 (UTC) From: "Himanshu Vashishtha (JIRA)" To: issues@hbase.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Created] (HBASE-8741) Mutations on Regions in recovery mode might have same sequenceIDs MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 Himanshu Vashishtha created HBASE-8741: ------------------------------------------ Summary: Mutations on Regions in recovery mode might have same sequenceIDs Key: HBASE-8741 URL: https://issues.apache.org/jira/browse/HBASE-8741 Project: HBase Issue Type: Bug Components: MTTR Affects Versions: 0.95.1 Reporter: Himanshu Vashishtha Assignee: Himanshu Vashishtha Currently, when opening a region, we find the maximum sequence ID from all its HFiles and then set the LogSequenceId of the log (in case the later is at a small value). This works good in recovered.edits case as we are not writing to the region until we have replayed all of its previous edits. With distributed log replay, if we want to enable writes while a region is under recovery, we need to make sure that the logSequenceId > maximum logSequenceId of the old regionserver. Otherwise, we might have a situation where new edits have same (or smaller) sequenceIds. We can store region level information in the WALTrailer, than this scenario could be avoided by: a) reading the trailer of the "last completed" file, i.e., last wal file which has a trailer and, b) completely reading the last wal file (this file would not have the trailer, so it needs to be read completely). In future, if we switch to multi wal file, we could read the trailer for all completed WAL files, and reading the remaining incomplete files. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira