[HBASE-7305] ZK based Read/Write locks for table operations

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.95.0
• Component/s: Client, master, Zookeeper
• Hadoop Flags: Reviewed
• Release Note: Added a read/write lock implementation based on zookeeper recipe, and a table lock per HBase table. Master operations acquire a write lock to the table. Configuration, "hbase.table.lock.enable" can be used to disable the implementation.
• Tags: 0.96notable
• Assignee: Enis Soztutar
• Reporter: Enis Soztutar
• Created: 08/Dec/12 00:16
• Updated: 15/Oct/13 04:46
• Resolved: 22/Feb/13 00:20

Description

This has started as forward porting of HBASE-5494 and HBASE-5991 from the 89-fb branch to trunk, but diverged enough to have it's own issue.

The idea is to implement a zk based read/write lock per table. Master initiated operations should get the write lock, and region operations (region split, moving, balance?, etc) acquire a shared read lock.

Issue Links

• is related to: HBASE-7848 Use ZK-based read/write lock to make flush-type snapshot robust against table enable/disable/alter
• relates to: HBASE-7546 Obtain a table read lock on region split operations
• relates to: HBASE-7980 TestZKInterProcessReadWriteLock fails occasionally in QA test run
• relates to: HBASE-5494 Introduce a zk hosted table-wide read/write lock so only one table operation at a time
• relates to: HBASE-5991 Introduce sequential ZNode based read/write locks
• relates to: HBASE-7374 Expose master table operations for coprocessors by way of MasterServices

Sub-Tasks

• Improve javadoc to including more about table lock semantics (failure handling, canonical usage pattern, what the lock guards): Open