[jira] [Created] (IMPALA-10235) Averaged timer profile counters can be negative for trivial queries

["Sahil Takiar (Jira)" <ji...@apache.org>]

Sahil Takiar created IMPALA-10235:
-------------------------------------

             Summary: Averaged timer profile counters can be negative for trivial queries
                 Key: IMPALA-10235
                 URL: https://issues.apache.org/jira/browse/IMPALA-10235
             Project: IMPALA
          Issue Type: Bug
            Reporter: Sahil Takiar
         Attachments: profile-output.txt

Steps to reproduce on master:
{code}
stakiar @ stakiar-desktop -bash ~/Impala 2020-10-13 11:13:02 master
 [74] → ./bin/impala-shell.sh -q "select sleep(100) from functional.alltypes limit 25" -p > profile-output.txt
...
Query: select sleep(100) from functional.alltypes limit 25
Query submitted at: 2020-10-13 11:13:07 (Coordinator: http://stakiar-desktop:25000)
Query progress can be monitored at: http://stakiar-desktop:25000/query_plan?query_id=694f94671571d4d1:cdec9db900000000
Fetched 25 row(s) in 2.64s
{code}

Attached the contents of {{profile-output.txt}}

Relevant portion of the profile:

{code}
    Averaged Fragment F00:(Total: 2s603ms, non-child: 272.519us, % non-child: 0.01%)
...
       - CompletionTime: -1665218428.000ns
...
       - TotalThreadsTotalWallClockTime: -1686005515.000ns
         - TotalThreadsSysTime: 0.000ns
         - TotalThreadsUserTime: 2.151ms
...
       - TotalTime: -1691524485.000ns
{code}

For whatever reason, this only affects the averaged fragment profile. For this query, there was only one coordinator fragment and thus only one fragment instance. It showed normal values:

{code}
    Coordinator Fragment F00:
...
         - CompletionTime: 2s629ms
...
         - TotalThreadsTotalWallClockTime: 2s608ms
           - TotalThreadsSysTime: 0.000ns
           - TotalThreadsUserTime: 2.151ms
...
         - TotalTime: 2s603ms
{code}



--
This message was sent by Atlassian Jira
(v8.3.4#803005)