MySQL Bugs: #117719: The event scheduler is not working.

Bug #117719	The event scheduler is not working.
Submitted:	17 Mar 2:13
Reporter:	huazai huazai	Email Updates:
Status:	Open	Impact on me:	None
Category:	MySQL Server: Stored Routines	Severity:	S2 (Serious)
Version:	8.0.41	OS:	Any
Assigned to:	MySQL Verification Team	CPU Architecture:	Any
Description:
Setting a single database to read-only status may cause scheduled event tasks in other databases to fail.Even if the read-only attribute of a database that has already been set to read-only is removed, it still does not take effect.

How to repeat:
【1】 How to reproduce
create database test_1;
use test_1;
CREATE EVENT IF NOT EXISTS event_test_1
ON SCHEDULE EVERY 1 MINUTE
STARTS CURRENT_TIMESTAMP
DO select 1;

create database test_2;
use test_2;
CREATE EVENT IF NOT EXISTS event_test_1
ON SCHEDULE EVERY 1 MINUTE
STARTS CURRENT_TIMESTAMP
DO select 1;

select now();
select EVENT_NAME,EVENT_SCHEMA,INTERVAL_FIELD,STATUS,STARTS,CREATED,LAST_ALTERED,LAST_EXECUTED from information_schema.EVENTS;

【2】Execution result

mysql> select version();
+--------------+
| version()    |
+--------------+
| 8.0.41-debug |
+--------------+
1 row in set (0.00 sec)

mysql> create database test_1;
Query OK, 1 row affected (0.01 sec)

mysql> use test_1;
Database changed
mysql> CREATE EVENT IF NOT EXISTS event_test_1
    -> ON SCHEDULE EVERY 1 MINUTE
    -> STARTS CURRENT_TIMESTAMP
    -> DO select 1;
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> create database test_2;
Query OK, 1 row affected (0.01 sec)

mysql> use test_2;
Database changed
mysql> CREATE EVENT IF NOT EXISTS event_test_1
    -> ON SCHEDULE EVERY 1 MINUTE
    -> STARTS CURRENT_TIMESTAMP
    -> DO select 1;
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2025-03-17 08:58:56 |
+---------------------+
1 row in set (0.00 sec)

mysql> select EVENT_NAME,EVENT_SCHEMA,INTERVAL_FIELD,STATUS,STARTS,CREATED,LAST_ALTERED,LAST_EXECUTED from information_schema.EVENTS;
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| EVENT_NAME   | EVENT_SCHEMA | INTERVAL_FIELD | STATUS  | STARTS              | CREATED             | LAST_ALTERED        | LAST_EXECUTED       |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| event_test_1 | test_1       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 |
| event_test_1 | test_2       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
2 rows in set (0.01 sec)

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2025-03-17 08:59:59 |
+---------------------+
1 row in set (0.00 sec)

mysql> select EVENT_NAME,EVENT_SCHEMA,INTERVAL_FIELD,STATUS,STARTS,CREATED,LAST_ALTERED,LAST_EXECUTED from information_schema.EVENTS;
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| EVENT_NAME   | EVENT_SCHEMA | INTERVAL_FIELD | STATUS  | STARTS              | CREATED             | LAST_ALTERED        | LAST_EXECUTED       |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| event_test_1 | test_1       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:59:56 |
| event_test_1 | test_2       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:59:56 |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
2 rows in set (0.01 sec)

mysql> ALTER SCHEMA test_1 READ ONLY=1;
Query OK, 1 row affected (0.01 sec)

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2025-03-17 09:01:51 |
+---------------------+
1 row in set (0.00 sec)

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2025-03-17 09:03:49 |
+---------------------+
1 row in set (0.00 sec)

【Problem 1】The events in both databases are invalid.

mysql> select EVENT_NAME,EVENT_SCHEMA,INTERVAL_FIELD,STATUS,STARTS,CREATED,LAST_ALTERED,LAST_EXECUTED from information_schema.EVENTS;
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| EVENT_NAME   | EVENT_SCHEMA | INTERVAL_FIELD | STATUS  | STARTS              | CREATED             | LAST_ALTERED        | LAST_EXECUTED       |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| event_test_1 | test_1       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 09:00:56 |
| event_test_1 | test_2       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 09:01:56 |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
2 rows in set (0.01 sec)

【Problem 2】Even if the read-only attribute of test_1 is removed, it still does not work.

mysql> ALTER SCHEMA test_1 READ ONLY=0;
Query OK, 1 row affected (0.01 sec)

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2025-03-17 09:06:01 |
+---------------------+
1 row in set (0.00 sec)

mysql> select EVENT_NAME,EVENT_SCHEMA,INTERVAL_FIELD,STATUS,STARTS,CREATED,LAST_ALTERED,LAST_EXECUTED from information_schema.EVENTS;
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| EVENT_NAME   | EVENT_SCHEMA | INTERVAL_FIELD | STATUS  | STARTS              | CREATED             | LAST_ALTERED        | LAST_EXECUTED       |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
| event_test_1 | test_1       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 09:00:56 |
| event_test_1 | test_2       | MINUTE         | ENABLED | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 08:58:56 | 2025-03-17 09:01:56 |
+--------------+--------------+----------------+---------+---------------------+---------------------+---------------------+---------------------+
2 rows in set (0.00 sec)