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Vladimir Rodionov commented on HBASE-17852: ------------------------------------------- Backup/Delete/Merge operations must be executed in a transactional manner. Backup system table keeps data (meta-data) which allows to run backups and others commands. During backup create, delete or merge, we update backup system table multiple times and do not want these updates to be partial ones (when operation fails), because *it will prevent further backups/deletes/merges after a failure*. That is why we take snapshot of a backup system table and restore this table from snapshot, previously taken, in case of a command (create/delete/merge) failure. By consistency of data I mean - no partial updates should be visible to a user after operation completes (either successfully or not). Partial updates in a backup system tables == corruption of a system table and MUST be avoided. When corruption happens - the only way to restore backup system is to truncate backup system table and re-run all backups in full mode. > 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 > Fix For: 2.0.0-beta-1 > > Attachments: HBASE-17852-v1.patch, HBASE-17852-v2.patch, > HBASE-17852-v3.patch, HBASE-17852-v4.patch, HBASE-17852-v5.patch > > -- This message was sent by Atlassian JIRA (v6.4.14#64029)