[HBASE-18806] VerifyRep by snapshot need not to restore snapshot for each mapper

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-beta-2
• Fix Version/s: 2.0.0-beta-2, 2.0.0
• Component/s: Replication
• Hadoop Flags: Reviewed
• Assignee: Zheng Hu
• Reporter: Zheng Hu
• Created: 13/Sep/17 11:29
• Updated: 21/Mar/18 22:23
• Resolved: 04/Jan/18 02:18

Description

In following method stack, seems like each mapper task will restore the snapshot. If we verify replication by a snapshot which has many hfiles, then we will take long time to restore snapshot. In our cluster, we took ~30min for the snapshot restoring when verify a big table.

Verifier.map
    |-------->  replicatedScanner = new TableSnapshotScanner(...)
                                                                |-------->  TableSnapshotScanner.init()
                                                                                          |-----> RestoreSnapshotHelper.copySnapshotForScanner

Issue Links

• links to: Review Board(master)