after TiDB introduce concurrent DDL, creating mysql database is not written to history DDL

[lance6716]

What did you do?

MySQL [(none)]> admin show ddl jobs 1000;

What did you expect to see?

MySQL [(none)]> admin show ddl jobs 1000;
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
| JOB_ID | DB_NAME | TABLE_NAME                       | JOB_TYPE      | SCHEMA_STATE | SCHEMA_ID | TABLE_ID | ROW_COUNT | CREATE_TIME         | START_TIME          | END_TIME            | STATE  |
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
...
|      6 | mysql   | user                             | create table  | public       |         3 |        5 |         0 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | synced |
|      4 | mysql   |                                  | create schema | public       |         3 |        0 |         0 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | synced |
|      2 | test    |                                  | create schema | public       |         1 |        0 |         0 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | 2022-07-28 15:20:50 | synced |
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
34 rows in set (0.014 sec)

What did you see instead?

MySQL [(none)]> admin show ddl jobs 1000;
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
| JOB_ID | DB_NAME | TABLE_NAME                       | JOB_TYPE      | SCHEMA_STATE | SCHEMA_ID | TABLE_ID | ROW_COUNT | CREATE_TIME         | START_TIME          | END_TIME            | STATE  |
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
...
|      5 | mysql   | user                             | create table  | public       |         1 |        4 |         0 | 2022-07-28 15:18:18 | 2022-07-28 15:18:18 | 2022-07-28 15:18:18 | synced |
|      3 | test    |                                  | create schema | public       |         2 |        0 |         0 | 2022-07-28 15:18:18 | 2022-07-28 15:18:18 | 2022-07-28 15:18:18 | synced |
+--------+---------+----------------------------------+---------------+--------------+-----------+----------+-----------+---------------------+---------------------+---------------------+--------+
33 rows in set (0.018 sec)

So CDC's logic about history DDL is not compatible.

Versions of the cluster

Release Version: v6.2.0-alpha-453-g2a9350923
Edition: Community
Git Commit Hash: 2a935092309bb631a5453950f4e5a3f5e0d729a1
Git Branch: HEAD
UTC Build Time: 2022-07-21 07:08:35
GoVersion: go1.18.3
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: unistore

[lance6716]

I'm not sure about CDC's execution path, will it really create an empty Snapshot rather than create it from meta? I choose major severity and let other developer decide it.

cc @liuzix @hi-rustin

[jebter]

/label affects-6.2