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https://issues.apache.org/jira/browse/HBASE-17852?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladimir Rodionov updated HBASE-17852:
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    Status: Patch Available  (was: Open)

> Add Fault tolerance to HBASE-14417 (Support bulk loaded files in incremental 
> backup)
> ------------------------------------------------------------------------------------
>
>                 Key: HBASE-17852
>                 URL: https://issues.apache.org/jira/browse/HBASE-17852
>             Project: HBase
>          Issue Type: Sub-task
>            Reporter: Vladimir Rodionov
>            Assignee: Vladimir Rodionov
>            Priority: Major
>             Fix For: 2.0.0
>
>         Attachments: HBASE-17852-v10.patch, screenshot-1.png
>
>
> Design approach rollback-via-snapshot implemented in this ticket:
> # Before backup create/delete/merge starts we take a snapshot of the backup 
> meta-table (backup system table). This procedure is lightweight because meta 
> table is small, usually should fit a single region.
> # When operation fails on a server side, we handle this failure by cleaning 
> up partial data in backup destination, followed by restoring backup 
> meta-table from a snapshot. 
> # When operation fails on a client side (abnormal termination, for example), 
> next time user will try create/merge/delete he(she) will see error message, 
> that system is in inconsistent state and repair is required, he(she) will 
> need to run backup repair tool.
> # To avoid multiple writers to the backup system table (backup client and 
> BackupObserver's) we introduce small table ONLY to keep listing of bulk 
> loaded files. All backup observers will work only with this new tables. The 
> reason: in case of a failure during backup create/delete/merge/restore, when 
> system performs automatic rollback, some data written by backup observers 
> during failed operation may be lost. This is what we try to avoid.
> # Second table keeps only bulk load related references. We do not care about 
> consistency of this table, because bulk load is idempotent operation and can 
> be repeated after failure. Partially written data in second table does not 
> affect on BackupHFileCleaner plugin, because this data (list of bulk loaded 
> files) correspond to a files which have not been loaded yet successfully and, 
> hence - are not visible to the system 



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