[HBASE-26864] SplitTableRegionProcedure calls openParentRegions() at a wrong state during rollback.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.10
• Fix Version/s: 2.5.0, 3.0.0-alpha-3, 2.4.12
• Component/s: Region Assignment
• Hadoop Flags: Reviewed
• Assignee: Huaxiang Sun
• Reporter: Huaxiang Sun
• Created: 18/Mar/22 19:59
• Updated: 01/Sep/22 10:57
• Resolved: 26/Mar/22 19:22

Description

Changed the issue title and description for the scope of the work. 

there is a bug in handling Rollback in SplitTableRegionProcedure.

https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/SplitTableRegionProcedure.java#L304

https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/SplitTableRegionProcedure.java#L385

In the state machine:


        case SPLIT_TABLE_REGION_CLOSE_PARENT_REGION:
          addChildProcedure(createUnassignProcedures(env));
          // Comments from HX:
          // createUnassignProcedures() can throw out IOException. If this happens,
          // it wont reach state SPLIT_TABLE_REGIONS_CHECK_CLOSED_REGION and no parent regions
          // is closed as all created UnassignProcedures are rolled back. If it rolls back with
          // state SPLIT_TABLE_REGION_CLOSE_PARENT_REGION, no need to call openParentRegion(),
          // otherwise, it will result in OpenRegionProcedure for an already open region.
          setNextState(SplitTableRegionState.SPLIT_TABLE_REGIONS_CHECK_CLOSED_REGIONS);
          break;


In the rollback,


        case SPLIT_TABLE_REGIONS_CHECK_CLOSED_REGIONS:
          // Doing nothing, in SPLIT_TABLE_REGION_CLOSE_PARENT_REGION,
          // we will bring parent region online
          break;
        case SPLIT_TABLE_REGION_CLOSE_PARENT_REGION:
          // Comments from HX: 
          // OpenParentRegion() should not be called here as explained above.
          openParentRegion(env);
          break; 

Issue Links

• links to: GitHub Pull Request #4261