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https://issues.apache.org/jira/browse/HBASE-17852?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16329494#comment-16329494
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Appy commented on HBASE-17852:
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Replication is doing it, but it's already in hbase-server module so it's
definitely not the ideal example. But I think its possible to do procv2 +
backup without tight integration with hbase-server i.e. while keeping things in
separate module. Won't be surprised if it requires some refactoring/small
design improvements in proc2 code itself, but that'll be all for good. Maybe
backup module become the poster face for "Building features with procv2" and we
make replication do the same.
> 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-v1.patch, HBASE-17852-v2.patch,
> HBASE-17852-v3.patch, HBASE-17852-v4.patch, HBASE-17852-v5.patch,
> HBASE-17852-v6.patch, HBASE-17852-v7.patch, HBASE-17852-v8.patch,
> HBASE-17852-v9.patch
>
>
> 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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