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https://issues.apache.org/jira/browse/HBASE-13031?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14319171#comment-14319171
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Jesse Yates edited comment on HBASE-13031 at 2/12/15 10:58 PM:
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The problem I saw with that is they (flurry) don't want to keep around an
entire second copy of the table if there is a compaction happening.... which
does bring up the question of, what good is a snapshot if it doesn't capture
the state of an entire table? If you have writes happening at the same time
(which causes the compaction) then the partial snapshots will never be 'up to
date'.
or, what Andrew said :)
was (Author: jesse_yates):
The problem I saw with that is they (flurry) don't want to keep around an
entire second copy of the table if there is a compaction happening.... which
does bring up the question of, what good is a snapshot if it doesn't capture
the state of an entire table? If you have writes happening at the same time
(which causes the compaction) then the partial snapshots will never be 'up to
date'.
> Ability to snapshot based on a key range
> ----------------------------------------
>
> Key: HBASE-13031
> URL: https://issues.apache.org/jira/browse/HBASE-13031
> Project: HBase
> Issue Type: Improvement
> Reporter: churro morales
> Assignee: churro morales
> Fix For: 2.0.0, 0.94.26, 1.1.0, 0.98.11
>
>
> Posted on the mailing list and seems like some people are interested. A
> little background for everyone.
> We have a very large table, we would like to snapshot and transfer the data
> to another cluster (compressed data is always better to ship). Our problem
> lies in the fact it could take many weeks to transfer all of the data and
> during that time with major compactions, the data stored in dfs has the
> potential to double which would cause us to run out of disk space.
> So we were thinking about allowing the ability to snapshot a specific key
> range.
> Ideally I feel the approach is that the user would specify a start and stop
> key, those would be associated with a region boundary. If between the time
> the user submits the request and the snapshot is taken the boundaries change
> (due to merging or splitting of regions) the snapshot should fail.
> We would know which regions to snapshot and if those changed between when the
> request was submitted and the regions locked, the snapshot could simply fail
> and the user would try again, instead of potentially giving the user more /
> less than what they had anticipated. I was planning on storing the start /
> stop key in the SnapshotDescription and from there it looks pretty straight
> forward where we just have to change the verifier code to accommodate the key
> ranges.
> If this design sounds good to anyone, or if I am overlooking anything please
> let me know. Once we agree on the design, I'll write and submit the patches.
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