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https://issues.apache.org/jira/browse/HBASE-12332?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14242078#comment-14242078
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Jingcheng Du commented on HBASE-12332:
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Thanks Jon [~jmhsieh], we will add such tests.
>>The problem is that if we are in the middle of reading a mob file and it is
>>moved to the archive, the read could fail and it is not clear if they read
>>would be retried against the new location from the same spot.
I think it's not a problem. When the read fails after the file is archived, the
mob will try to read the file from the archive. This case will be added in
another JIRA to make sure the current implementation is right.
I call tell how the read works in mob based on the mentioned steps.
1) Create a table A with mob, add cells to it. These cells with tags of table A.
2) Snapshot it.
3) Clone it as a different table B. Now the cells in the table B still have
tags of table A.
4) Read from the snapshot, the reader find the tag of table is A not B itself,
will try to read the file from the candidate directories of A (working
directory or archive of A), then it finds the file in the working directory of
A.
5) Delete the original table A, the mob files are archived. The reader try to
read the next candidate directory which is the archive of A, then it will find
the file there.
We will add test cases to prove it. Thanks.
> [mob] use filelink instad of retry when resolving an hfilelink.
> ---------------------------------------------------------------
>
> Key: HBASE-12332
> URL: https://issues.apache.org/jira/browse/HBASE-12332
> Project: HBase
> Issue Type: Sub-task
> Components: mob
> Affects Versions: hbase-11339
> Reporter: Jonathan Hsieh
> Fix For: hbase-11339
>
> Attachments: HBASE-12332-V1.diff
>
>
> in the snapshot code, hmobstore was modified to traverse an hfile link to a
> mob. Ideally this should use the transparent filelink code to read the data.
> Also there will likely be some issues with the mob file cache with these
> links.
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