[HBASE-5494] Introduce a zk hosted table-wide read/write lock so only one table operation at a time

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.89-fb
• Hadoop Flags: Reviewed
• Assignee: Alex Feinberg
• Reporter: Michael Stack
• Created: 29/Feb/12 21:25
• Updated: 13/Jun/22 15:33
• Resolved: 12/May/12 04:16

Description

I saw this facility over in the accumulo code base.

Currently we just try to sort out the mess when splits come in during an online schema edit; somehow we figure we can figure all possible region transition combinations and make the right call.

We could try and narrow the number of combinations by taking out a zk table lock when doing table operations.

For example, on split or merge, we could take a read-only lock meaning the table can't be disabled while these are running.

We could then take a write only lock if we want to ensure the table doesn't change while disabling or enabling process is happening.

Shouldn't be too hard to add.

Issue Links

• is depended upon by: HBASE-5487 Generic framework for Master-coordinated tasks
• is depended upon by: HBASE-5504 Online Merge
• is related to: HBASE-7305 ZK based Read/Write locks for table operations