[IMPALA-7828] test_mem_leak() is flaky

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 3.2.0
• Fix Version/s: Impala 3.2.0
• Component/s: Backend
• Labels: broken-build
• Epic Color: ghx-label-3
• Assignee: Michael Ho
• Reporter: Michael Ho
• Created: 07/Nov/18 18:02
• Updated: 21/Nov/18 00:52
• Resolved: 08/Nov/18 18:52

Description

Before IMPALA-4063, the error message detected during FragmentInstanceState::Close() was always lost. After IMPALA-4063, we may sometimes get the error message in FragmentInstanceState::Close(). It's non-deterministic as the fragment instance thread may race with the query state thread which reports the final status. The test currently tries to handle this non-determinism by using "row_regex:.*" in the -ERRORS- section but it doesn't seem to work.

Let's unbreak the test for now. Longer run, we need to move the point in which all fragment instances are done after FragmentInstanceState::Close() so things will become deterministic. This may have implication to query completion time so performance may need to be evaluated.

Stacktrace
query_test/test_udfs.py:313: in test_ir_functions
    self.run_test_case('QueryTest/udf-no-expr-rewrite', vector, use_db=unique_database)
common/impala_test_suite.py:496: in run_test_case
    self.__verify_results_and_errors(vector, test_section, result, use_db)
common/impala_test_suite.py:358: in __verify_results_and_errors
    replace_filenames_with_placeholder)
common/test_result_verifier.py:362: in verify_raw_results
    verify_errors(expected_errors, actual_errors)
common/test_result_verifier.py:314: in verify_errors
    VERIFIER_MAP['VERIFY_IS_EQUAL'](expected, actual)
common/test_result_verifier.py:271: in verify_query_result_is_equal
    assert expected_results == actual_results
E   assert Comparing QueryTestResults (expected vs actual):
E     row_regex:.* != None
E     Number of rows returned (expected vs actual): 1 != 0