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https://issues.apache.org/jira/browse/HBASE-25761?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17364035#comment-17364035
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Francis Christopher Liu commented on HBASE-25761:
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Thanks for your comment [~zhangduo].
>From what I can gather from the rough PoC that I did was that the salient
>difference between this implementation and the root table implementation is
>around the theme of backward compatibility. Some of which might seem valuable
>to the community hence I wonder what the community thinks:
1. The compatibility code is built-in as part of the core implementation there
is no extra code to support backward compatibility
2. It introduces no new major artifacts, such that:
- If hbase:meta region is not split it operationally will behave pretty much
exactly the same way as before (no operator changes, user changes, etc). As
opposed to having to be aware of the new hbase:root region from the get go.
- If hbase:meta region is split. Users/Operators only have to worry about
hbase:meta regions (which one would have to in any split meta implementation),
no new hbase:root table to worry about. Although yes one would need to be aware
of the first meta region getting assigned first.
3. I think it might also be smoother to get reviewed and checked in
- Intuitively given 1 & 2, I think it might be easier to add things more
piece meal vs root table
> POC: hbase:meta,,1 as ROOT
> --------------------------
>
> Key: HBASE-25761
> URL: https://issues.apache.org/jira/browse/HBASE-25761
> Project: HBase
> Issue Type: Sub-task
> Reporter: Michael Stack
> Assignee: Francis Christopher Liu
> Priority: Major
>
> One of the proposals up in the split-meta design doc suggests a
> sleight-of-hand where the current hard-coded hbase:meta,,1 Region is
> leveraged to serve as first Region of a split hbase:meta but also does
> double-duty as 'ROOT'. This suggestion was put aside as a complicating
> recursion in chat but then Francis noticed on a re-read of the BigTable
> paper, that this is how they describe they do 'ROOT': "The root tablet is
> just the first tablet in the METADATA table, but is treated specially -- it
> is never split..."
> This issue is for playing around with this notion to see what the problems
> are so can do a better description of this approach here, in the design:
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit?ts=606c120f#heading=h.ikbhxlcthjle
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