Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm
Precedence: bulk
Date: Sat, 20 Jun 2015 00:10:00 +0000 (UTC)
From: "Duo Zhang (JIRA)" <jira@apache.org>
To: issues@hbase.apache.org
Message-ID: <JIRA.12838977.1434668557000.125303.1434759000724@Atlassian.JIRA>
In-Reply-To: <JIRA.12838977.1434668557000@Atlassian.JIRA>
References: <JIRA.12838977.1434668557000@Atlassian.JIRA>
 <JIRA.12838977.1434668557117@arcas>
Subject: [jira] [Commented] (HBASE-13937) Partially revert HBASE-13172
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HBASE-13937?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14594157#comment-14594157 ] 

Duo Zhang commented on HBASE-13937:
-----------------------------------

{quote}
thus guaranteeing that the region server cannot accept any more writes.
{quote}
But still readable right? Does HBase guarantee this level of consistency?
1. A writes row to HBase.
2  A tells B to read the row.
3. B can read the row from HBase.

If not, then I think remove recoverLease is enough here. Otherwise we still to make sure that the regionserver can not process any request.

And I think this discussion should be in the parent issue, so +1 on patch v3 :)

> Partially revert HBASE-13172 
> -----------------------------
>
>                 Key: HBASE-13937
>                 URL: https://issues.apache.org/jira/browse/HBASE-13937
>             Project: HBase
>          Issue Type: Sub-task
>          Components: Region Assignment
>            Reporter: Enis Soztutar
>            Assignee: Enis Soztutar
>             Fix For: 0.98.14, 1.2.0, 1.1.1, 1.3.0
>
>         Attachments: hbase-13937_v1.patch, hbase-13937_v2.patch, hbase-13937_v3.patch
>
>
> HBASE-13172 is supposed to fix a UT issue, but causes other problems that parent jira (HBASE-13605) is attempting to fix. 
> However, HBASE-13605 patch v4 uncovers at least 2 different issues which are, to put it mildly, major design flaws in AM / RS. 
> Regardless of 13605, the issue with 13172 is that we catch {{ServerNotRunningYetException}} from {{isServerReachable()}} and return false, which then puts the Server to the {{RegionStates.deadServers}} list. Once it is in that list, we can still assign and unassign regions to the RS after it has started (because regular assignment does not check whether the server is in  {{RegionStates.deadServers}}. However, after the first assign and unassign, we cannot assign the region again since then the check for the lastServer will think that the server is dead. 
> It turns out that a proper patch for 13605 is very hard without fixing rest of  broken AM assumptions (see HBASE-13605, HBASE-13877 and HBASE-13895 for a colorful history). For 1.1.1, I think we should just revert parts of HBASE-13172 for now. 


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