Bug #120974 Client connection kill command doesn't kill process

• Submitted: 21 Jul 18:54
• Modified: 22 Jul 8:43
• Reporter: Valerie Rentz
• Status: Open
• Category: MySQL Server: Information schema
• Severity: S2 (Serious)
• Version: 8.0.34-26
• OS: Any
• CPU Architecture: Any

[21 Jul 18:54] Valerie Rentz

Description:
When running an information_schema query, cannot kill the query.

How to repeat:
Connect directly to the MySQL instance using localhost root privileges.  Run the following:

SELECT TABLE_ID, NAME
FROM INFORMATION_SCHEMA.INNODB_TABLES
WHERE TABLE_ID = 12345678;

The query runs a long time.  

Attempt to kill the process using any kill command, normal, etcetera.  The status says killed.
Connect again using the privileged user.
Now have original process and another duplicated process running.

| 1704  executing  SELECT TABLE_ID, NAME FROM INFORMATION_SCHEMA.INNODB_TABLES
WHERE TABLE_ID = 12345678 | 1662990 |         0 |             0 |
| 1849  executing  SELECT TABLE_ID, NAME FROM INFORMATION_SCHEMA.INNODB_TABLES
WHERE TABLE_ID = 12345678 |  320291 

This appears to affect these types of queries.  

Suggested fix:
The kill command using a privileged user should be able to do just that.

[22 Jul 7:36] MySQL Verification Team

Percona versions and 8.0.x are not supported.
Let us know if this is reproducible on 8.4.10 from dev.mysql.com