[IMPALA-11337] impala-shell can output the "Fetched X row(s)" line before the actual results

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 4.2.0
• Fix Version/s: Impala 4.2.0, Impala 4.1.1
• Component/s: Clients
• Epic Color: ghx-label-11
• Assignee: Joe McDonnell
• Reporter: Joe McDonnell
• Created: 06/Jun/22 18:20
• Updated: 23/Aug/22 05:49
• Resolved: 15/Jun/22 05:54

Description

In some scenarios, we are seeing that the "Fetched X row(s)" message is output before the actual data:

Query: SELECT * FROM test_table ORDER BY id DESC
Query submitted at: 2022-06-02 23:53:48 (Coordinator: https://coordinator:25000)
Query progress can be monitored at: https://coordinator:25000/query_plan?query_id=9d47858d6659cb87:2ccbdcdf00000000
Fetched 1 row(s) in 1.59s
0	john	10

The "Fetched X row(s)" message is going to stderr and the results are going to stdout, so this is not covered completely by the current tests. Nonetheless, we should expect the "Fetched X row(s)" output to happen after the results data is written.

We should add tests for this case and make sure that stdout is flushed prior to writing the "Fetched X row(s)" output.