[
https://issues.apache.org/jira/browse/IMPALA-11114?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Gergely Fürnstáhl resolved IMPALA-11114.
----------------------------------------
Fix Version/s: Impala 4.1.0
Resolution: Fixed
> calculate_tval fails with ZeroDevisionError if the standard deviations are 0
> ----------------------------------------------------------------------------
>
> Key: IMPALA-11114
> URL: https://issues.apache.org/jira/browse/IMPALA-11114
> Project: IMPALA
> Issue Type: Bug
> Reporter: Gergely Fürnstáhl
> Assignee: Gergely Fürnstáhl
> Priority: Minor
> Fix For: Impala 4.1.0
>
>
> Possible cause:
> _Rounding of the data or other forms of truncation could give zero standard
> deviation when in fact you have some. And if the difference that you are
> trying to measure is within your measurement error that is a problem not
> addressed by the t-test._
> [https://stats.stackexchange.com/questions/78570/t-test-with-sample-standard-deviation-of-zero-possible/275879]
> Full log:
> {code:java}
> Traceback (most recent call last):
> File "/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py",
> line 1131, in <module>
> report = Report(grouped, ref_grouped)
> File "/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py",
> line 494, in __init__
> self.__analyze()
> File "/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py",
> line 514, in __analyze
> query_comparison_row = Report.QueryComparisonRow(results, ref_results)
> File "/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py",
> line 370, in __init__
> self.__check_perf_change_significance(results, ref_results))
> File "/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py",
> line 390, in __check_perf_change_significance
> ref_stat[AVG], ref_stat[STDDEV], ref_stat[ITERATIONS])
> File "/home/gfurnstahl/Impala/tests/util/calculation_util.py", line 65, in
> calculate_tval
> return (avg - ref_avg) / sem
> ZeroDivisionError: float division by zero
> Traceback (most recent call last):
> File "bin/single_node_perf_run.py", line 359, in <module>
> main()
> File "bin/single_node_perf_run.py", line 349, in main
> perf_ab_test(options, args)
> File "bin/single_node_perf_run.py", line 267, in perf_ab_test
> compare(temp_dir, hash_a, hash_b)
> File "bin/single_node_perf_run.py", line 175, in compare
> report_benchmark_results(file_a, file_b, description)
> File "bin/single_node_perf_run.py", line 166, in report_benchmark_results
> stdout=f)
> File
> "/home/gfurnstahl/Impala/toolchain/toolchain-packages-gcc7.5.0/python-2.7.16/lib/python2.7/subprocess.py",
> line 190, in check_call
> raise CalledProcessError(retcode, cmd)
> subprocess.CalledProcessError: Command
> '['/home/gfurnstahl/Impala/tests/benchmark/report_benchmark_results.py',
> '--reference_result_file=/home/gfurnstahl/Impala/perf_results/perf_run_0SdUw7/a87f8c5df9f6fbf8d468921642d7ec3d37c5f4de.json',
>
> '--input_result_file=/home/gfurnstahl/Impala/perf_results/perf_run_0SdUw7/b4d04112559c3f04ebf42b36deb1cd537dea78c4.json',
> '--report_description="a87f8c5df9f6fbf8d468921642d7ec3d37c5f4de vs
> b4d04112559c3f04ebf42b36deb1cd537dea78c4"']' returned non-zero exit status
> 1{code}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
