Rajesh Balamohan created HIVE-22850: ---------------------------------------
Summary: Optimise lock acquisition in TxnHandler Key: HIVE-22850 URL: https://issues.apache.org/jira/browse/HIVE-22850 Project: Hive Issue Type: Improvement Components: Hive Reporter: Rajesh Balamohan With concurrent queries, time taken for lock acquisition increases substantially. As part of lock acquisition in the query, {{TxnHandler::checkLock}} gets invoked. This involves getting a mutex and compare the locks being requested for, with that of existing locks in {{HIVE_LOCKS}} table. With concurrent queries, time taken to do this check increase and this significantly increases the time taken for getting mutex for other threads. In a synthetic workload, it was in the order of 10+ seconds. This codepath can be optimized when all lock requests are SHARED_READ. -- This message was sent by Atlassian Jira (v8.3.4#803005)