kill statement can't interrupt subquery

[tiancaiamao]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

As I've mentioned in #10959, the MAX_EXECUTION_TIME hint can only kill queries in execute phase, kill statement has the same problem.

This query can be killed

select 1,  sleep(5);

while this cannot:

select 1,  (select sleep(5));

2. What did you expect to see?

kill tidb xxx should interrupt this query select 1, (select sleep(5));

3. What did you see instead?

The query is not interrupted

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

git hash 21d2590

[wjhuang2016]

related to #11905

[ghost]

I checked this bug against master, and it's fixed:

mysql> select tidb_version()\G
*************************** 1. row ***************************
tidb_version(): Release Version: v4.0.0-beta.2-769-g2024e4463
Edition: Community
Git Commit Hash: 2024e44636f2fb9798982a1cc0ec22176e07f5c1
Git Branch: master
UTC Build Time: 2020-07-14 09:26:07
GoVersion: go1.13
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false
1 row in set (0.00 sec)

mysql> select 1,  sleep(5);
+---+----------+
| 1 | sleep(5) |
+---+----------+
| 1 |        0 |
+---+----------+
1 row in set (5.00 sec)

mysql> select 1,  sleep(10); <-- this one was killed, hence sleep returning 1
+---+-----------+
| 1 | sleep(10) |
+---+-----------+
| 1 |         1 |
+---+-----------+
1 row in set (3.86 sec)

I am going to close this issue now.