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https://issues.apache.org/jira/browse/HBASE-17460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15865086#comment-15865086
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Bhupendra Kumar Jain commented on HBASE-17460:
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This patch will have one incompatible behavior change for enable table
replication API.
As per the earlier behavior, If the replication is enabled , user executes the
enable table replication command again and If table descriptor matches , It
will check the replication scope for each column family and if any of the
column family scope is not enabled, it will enable it. otherwise it will do
nothing and final result is success. But as per the patch, it will throw
exception if replication is already enabled.
I think, To handle the cyclic replication case, Only ignoring the replication
scope from comparison should be enough. No need to check to
isReplicationEnabled for local cluster.
> enable_table_replication can not perform cyclic replication of a table
> ----------------------------------------------------------------------
>
> Key: HBASE-17460
> URL: https://issues.apache.org/jira/browse/HBASE-17460
> Project: HBase
> Issue Type: Bug
> Components: Replication
> Reporter: NITIN VERMA
> Assignee: NITIN VERMA
> Labels: replication
> Fix For: 2.0.0, 1.4.0
>
> Attachments: 17460.branch-1.v3.txt, HBASE-17460.patch,
> HBASE-17460_v2.patch, HBASE-17460_v3.patch, HBASE-17460_v4.patch
>
> Original Estimate: 96h
> Remaining Estimate: 96h
>
> The enable_table_replication operation is broken for cyclic replication of
> HBase table as we compare all the properties of column families (including
> REPLICATION_SCOPE).
> Below is exactly what happens:
> 1. Running "enable_table_replication 'table1' " opeartion on first cluster
> will set the REPLICATION_SCOPE of all column families to peer id '1'. This
> will also create a table on second cluster where REPLICATION_SCOPE is still
> set to peer id '0'.
> 2. Now when we run "enable_table_replication 'table1'" on second cluster, we
> compare all the properties of table (including REPLICATION_SCOPE_, which
> obviously is different now.
> I am proposing a fix for this issue where we should avoid comparing
> REPLICATION_SCOPE inside HColumnDescriotor::compareTo() method, especially
> when replication is not already enabled on the desired table.
> I have made that change and it is working. I will submit the patch soon.
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