[IMPALA-4381] Incorrect results for TPC-H Q4 in test_mem_usage_scaling.py

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 2.8.0
• Component/s: Backend
• Labels: correctness
• Target Version: Impala 2.8.0
• Assignee: Jim Apple
• Reporter: Tim Armstrong
• Created: 27/Oct/16 00:54
• Updated: 02/Nov/16 20:53
• Resolved: 02/Nov/16 20:53

Description

I noticed that I was reproducibly getting incorrect results for some tests in test_mem_usage_scaling.py. E.g. q4.

I was able to bisect the problem to the commit 61fcb489745f3f0b3f1abbf9fbf666a29a6363de "IMPALA-4300: Speed up BloomFilter::Or with SIMD"

I'm not sure why we're not seeing on the jenkins machines - maybe it's related to the CPU I'm running on.