[jira] [Commented] (HBASE-4083) If Enable table is not completed and is partial, then scanning of the table is not working

["ramkrishna.s.vasudevan (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-4083?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13063330#comment-13063330 ] 

ramkrishna.s.vasudevan commented on HBASE-4083:
-----------------------------------------------

This issue is similar to HBASE-4052 (improper disabling of table).
Following scenarios needs to be considered.
If a table T1 has three regions R1, R2 and R3 
The table T1 is disabled successfully.
We now issue an enable command for T1
Scenario 1:
===========
All the regions R1, R2 and R3 are onlined and the state in zookeeper for the table is ENABLING and then the Active master went down,
R1- online
R2- online			T1-ENABLING
R3-online
	Here the scan will work properly but the table state will be ENABLING.(This is not a problem in the user perspective when he tries to scan but as per the state of the system this is a serious concern).
Scenario:2
==========
None of the regions R1, R2 and R3 are onlined but the Active Master went down when the zookeeper state for the table was in ENABLING.
R1- Offlined
R2- Offlined			T1-ENABLING
R3-Offlined
Here the scan operation performed on the table will throw NotServingRegionException.
Scenario:3
========
The regions R1, R2  are onlined and R3 are not yet onlined and the Active Master went down when the zookeeper state was ENABLING.
R1- online
R2- online		T1-ENABLING
R3-offlined

Here the offlined regions cannot be scanning and NotServingRegionException will be thrown. 


> If Enable table is not completed and is partial, then scanning of the table is not working 
> -------------------------------------------------------------------------------------------
>
>                 Key: HBASE-4083
>                 URL: https://issues.apache.org/jira/browse/HBASE-4083
>             Project: HBase
>          Issue Type: Bug
>            Reporter: ramkrishna.s.vasudevan
>            Assignee: ramkrishna.s.vasudevan
>
> Consider the following scenario
> Start the Master, Backup master and RegionServer.
> Create a table which in turn creates a region.
> Disable the table.
> Enable the table again. 
> Kill the Active master exactly at the point before the actual region assignment is started.
> Restart or switch master.
> Scan the table.
> NotServingRegionExcepiton is thrown.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira