[HIVE-10219] BytesBytesMultiHashMap::clear() can't be concurrently used with reads

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: llap
• Assignee: Sergey Shelukhin
• Reporter: Gopal Vijayaraghavan
• Created: 05/Apr/15 07:07
• Updated: 17/Feb/16 01:32
• Resolved: 07/Apr/15 19:01

Description

The semantics of the HashMap::clear() is unclear for concurrent access.

With HIVE-10128 fixes, the only remaining thread-safety concern is the behaviour of clear() calls.

Concurrent usage + clearing from HybridHash and VectorMapJoin operator will result in race conditions.

There is no valid clear() operations possible without knowledge of the cached nature and the ref-count of each hashtable.

Issue Links

• is related to: HIVE-10128 BytesBytesMultiHashMap does not allow concurrent read-only access