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Jingcheng Du commented on HBASE-16841: -------------------------------------- Thanks a lot [~huaxiang], I'll try to add the tests in this way. > Data loss in MOB files after cloning a snapshot and deleting that snapshot > -------------------------------------------------------------------------- > > Key: HBASE-16841 > URL: https://issues.apache.org/jira/browse/HBASE-16841 > Project: HBase > Issue Type: Bug > Components: mob, snapshots > Reporter: Jingcheng Du > Assignee: Jingcheng Du > Attachments: HBASE-16841-V2.patch, HBASE-16841-V3.patch, > HBASE-16841.patch > > > Running the following steps will probably lose MOB data when working with > snapshots. > 1. Create a mob-enabled table by running create 't1', {NAME => 'f1', IS_MOB > => true, MOB_THRESHOLD => 0}. > 2. Put millions of data. > 3. Run {{snapshot 't1','t1_snapshot'}} to take a snapshot for this table t1. > 4. Run {{clone_snapshot 't1_snapshot','t1_cloned'}} to clone this snapshot. > 5. Run {{delete_snapshot 't1_snapshot'}} to delete this snapshot. > 6. Run {{disable 't1'}} and {{delete 't1'}} to delete the table. > 7. Now go to the archive directory of t1, the number of .link directories is > different from the number of hfiles which means some data will be lost after > the hfile cleaner runs. > This is because, when taking a snapshot on a enabled mob table, each region > flushes itself and takes a snapshot, and the mob snapshot is taken only if > the current region is first region of the table. At that time, the flushing > of some regions might not be finished, and some mob files are not flushed to > disk yet. Eventually some mob files are not recorded in the snapshot manifest. > To solve this, we need to take the mob snapshot at last after the snapshots > on all the online and offline regions are finished in > {{EnabledTableSnapshotHandler}}. -- This message was sent by Atlassian JIRA (v6.3.4#6332)