[HIVE-13753] Make metastore client thread safe in DbTxnManager

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0, 2.1.0
• Fix Version/s: 1.3.0, 2.1.0
• Component/s: Transactions
• Target Version/s: 1.3.0, 2.1.0
• Assignee: Wei Zheng
• Reporter: Wei Zheng
• Created: 12/May/16 22:48
• Updated: 21/Jun/16 15:08
• Resolved: 16/May/16 17:27

Description

The fact that multiple threads sharing the same metastore client which is used for RPC to Thrift is not thread safe.

Race condition can happen when one sees "out of sequence response" error message from Thrift server. That means the response from the Thrift server is for a different request (by a different thread).

Solution will be to synchronize methods from the client side.