[HIVE-16571] HiveServer2: Prefer LIFO over round-robin for Tez session reuse

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.0.0
• Component/s: HiveServer2, Tez
• Target Version/s: 3.0.0
• Assignee: Gopal Vijayaraghavan
• Reporter: Gopal Vijayaraghavan
• Created: 02/May/17 22:31
• Updated: 22/May/18 23:57
• Resolved: 05/Jun/17 21:33

Description

Currently Tez session reuse is entirely round-robin, which means a single user might have to run upto 32 queries before reusing a warm session on a HiveServer2.

This is not the case when session reuse is disabled, with a user warming up their session on the 1st query.