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https://issues.apache.org/jira/browse/HBASE-29315?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Duo Zhang resolved HBASE-29315.
-------------------------------
Fix Version/s: 2.7.0
3.0.0-beta-2
2.6.3
2.5.12
Hadoop Flags: Reviewed
Resolution: Fixed
Pushed to all active branches.
Thanks [~charlesconnell]!
> Cancel Split/MergeTableRegionProcedure if table modification is in progress
> ---------------------------------------------------------------------------
>
> Key: HBASE-29315
> URL: https://issues.apache.org/jira/browse/HBASE-29315
> Project: HBase
> Issue Type: Bug
> Components: proc-v2
> Reporter: Charles Connell
> Assignee: Charles Connell
> Priority: Minor
> Labels: pull-request-available
> Fix For: 2.7.0, 3.0.0-beta-2, 2.6.3, 2.5.12
>
>
> When adding new replicas, ModifyTableProcedure roughly does the following:
> # Edits the table descriptor
> # Closes and opens all existing regions
> # Creates replication peer to support the new replica regions
> # Opens new replica regions
> When closing a region in step 2, the act of closing it can trigger a split.
> When the HMaster runs the SplitTableRegionProcedure, it roughly does:
> # Close the region to be split
> # Split the store files
> # Open the new daughter regions (including replicas)
> When a split is done as part of a ModifyTableProcedure that adds replicas, we
> get the following combination of behavior:
> # Edit the table descriptor
> # Close and open all existing regions, adding a SplitTableRegionProcedure to
> the HMaster's queue
> # To begin the SplitTableRegionProcedure, close region to be split
> # Split store files
> # Open the new daughter regions, including replicas, completing the
> SplitTableRegionProcedure
> # Create replication peer to support the new replica regions
> # Open new replica regions, even though some were already opened in step 5.
> Double-opening doesn't work, and the open procedures get stuck.
> -There are a few ways to correct this problem, but perhaps the most intuitive
> way is to use the existing lock mechanisms in the procedure system. The
> ModifyTableProcedure can lock the table from beginning to end, allowing only
> itself and its child procedures to modify the table. This would enforce in
> code what is already an implicit assumption in the implementation of the
> procedure – that nobody else open regions while it's running.-
> Discussed over
> [email|https://lists.apache.org/thread/0x4pxr5jt8cwprq6xhxr6d5g3lctlhhc].
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