Return-Path: X-Original-To: apmail-hbase-user-archive@www.apache.org Delivered-To: apmail-hbase-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id D6E46CF83 for ; Mon, 2 Jul 2012 17:38:28 +0000 (UTC) Received: (qmail 25733 invoked by uid 500); 2 Jul 2012 17:38:27 -0000 Delivered-To: apmail-hbase-user-archive@hbase.apache.org Received: (qmail 25691 invoked by uid 500); 2 Jul 2012 17:38:27 -0000 Mailing-List: contact user-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hbase.apache.org Delivered-To: mailing list user@hbase.apache.org Received: (qmail 25681 invoked by uid 99); 2 Jul 2012 17:38:27 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 02 Jul 2012 17:38:27 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=FSL_RCVD_USER,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of bryanck@gmail.com designates 209.85.160.41 as permitted sender) Received: from [209.85.160.41] (HELO mail-pb0-f41.google.com) (209.85.160.41) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 02 Jul 2012 17:38:18 +0000 Received: by pbbrp2 with SMTP id rp2so9632860pbb.14 for ; Mon, 02 Jul 2012 10:37:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-type:subject:date:message-id:to:mime-version:x-mailer; bh=kRhpWjJNrU77dokv4meDNOKQOj0la2/jaETbPPt8ej4=; b=WSRBXw2ClX1+9iiqV9djJu3YGq4Jz/CqASyTCHCrGK7knS3zL5OfSGiFS+QKqzmC1n qv+829DTD7GyNKHUKprV84BmuckBXy84bPNZC7wLObu/HkBd5yekeXFZKi3eDJNxlH5l izapkLq+yIsyaw/Kz0Yc47UWv2RluYNcxfrVts0ZzVbBnSm65MVabnDM3fPdebilZVax c/Avjxn8JgSU++qNu1aGIBPtAt26X6M7wyS7zCimuFnKn2bhddcMQrF1UcERVYLBPQ4M Xa9fRPBbNXiKBDx6OTc0QVYkOxaV3Y+opNIEol3YXYrVcYykednCPoa0UxoCu/PArMM2 jKBQ== Received: by 10.68.225.6 with SMTP id rg6mr32633585pbc.100.1341250676903; Mon, 02 Jul 2012 10:37:56 -0700 (PDT) Received: from [10.41.41.146] (71-6-107-162.static-ip.telepacific.net. [71.6.107.162]) by mx.google.com with ESMTPS id jz4sm13453851pbc.17.2012.07.02.10.37.55 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 02 Jul 2012 10:37:55 -0700 (PDT) From: Bryan Keller Content-Type: multipart/alternative; boundary="Apple-Mail=_38950110-FAA7-4948-92FD-0C823A181DDE" Subject: WAL corruption Date: Mon, 2 Jul 2012 10:37:53 -0700 Message-Id: <1E6B8C7E-80BF-4758-BF30-67EE8EAB3934@gmail.com> To: user@hbase.apache.org Mime-Version: 1.0 (Apple Message framework v1278) X-Mailer: Apple Mail (2.1278) --Apple-Mail=_38950110-FAA7-4948-92FD-0C823A181DDE Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii During an upgrade of my cluster to 0.90 to 0.92 over the weekend, the = WAL (files in the /hbase/.logs directory) was corrupted and it prevented = HBase from starting up. The exact exception was "java.io.IOException: = Could not obtain the last block locations" on the WAL files. I was able to recover by deleting the /hbase/.logs directory. My = question is, if HBase had no pending updates, i.e. nothing writing to = it, is there any risk of data loss by deleting the WAL directory? For = example, does rebalancing, flushing, or compaction use the WAL or is the = WAL used only for inserts/updates/deletes?= --Apple-Mail=_38950110-FAA7-4948-92FD-0C823A181DDE--