Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm
Precedence: bulk
Date: Fri, 19 Feb 2016 07:43:18 +0000 (UTC)
From: "Stephen Yuan Jiang (JIRA)" <jira@apache.org>
To: issues@hbase.apache.org
Message-ID: <JIRA.12938402.1455152922000.91234.1455867798127@Atlassian.JIRA>
In-Reply-To: <JIRA.12938402.1455152922000@Atlassian.JIRA>
References: <JIRA.12938402.1455152922000@Atlassian.JIRA>
 <JIRA.12938402.1455152922737@arcas>
Subject: [jira] [Commented] (HBASE-15251) During a cluster restart, Hmaster
 thinks it is a failover by mistake
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HBASE-15251?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15153864#comment-15153864 ] 

Stephen Yuan Jiang commented on HBASE-15251:
--------------------------------------------

+1 the updated patch (v1) looks good to me.

> During a cluster restart, Hmaster thinks it is a failover by mistake
> --------------------------------------------------------------------
>
>                 Key: HBASE-15251
>                 URL: https://issues.apache.org/jira/browse/HBASE-15251
>             Project: HBase
>          Issue Type: Bug
>          Components: master
>    Affects Versions: 2.0.0, 0.98.15
>            Reporter: Clara Xiong
>            Assignee: Clara Xiong
>         Attachments: HBASE-15251-master-v1.patch, HBASE-15251-master.patch
>
>
> We often need to do cluster restart as part of release for a cluster of > 1000 nodes. We have tried our best to get clean shutdown but 50% of the time, hmaster still thinks it is a failover. This increases the restart time from 5 min to 30 min and decreases locality from 99% to 5% since we didn't use a locality-aware balancer. We had a bug HBASE-14129 but the fix didn't work. 
> After adding more logging and inspecting the logs, we identified two things that trigger the failover handling:
> 1.  When Hmaster.AssignmentManager detects any dead servers on service manager during joinCluster(), it determines this is a failover without further check. I added a check whether there is even any region assigned to these servers. During a clean restart, the regions are not even assigned.
> 2. When there are some leftover empty folders for log and split directories or empty wal files, it is also treated as a failover. I added a check for that. Although this can be resolved by manual cleanup, it is still too tedious for restarting a large cluster.
> Patch will follow shortly. The fix is tested and used in production now.


--
This message was sent by Atlassian JIRA
(v6.3.4#6332)