Amazon RDS for MySQL is deprecating minor versions 8.0.31, 8.0.29 and 8.0.28 on March 29, 2024

Question

Good day, on April the 29th AWS did a forced upgrade to our MySQL on RDS istance to version 8.0.31 from an older one we had.
Immediatelly after and without any modification our APP installed on a EC2 istance connected to DB istance where MySQL server is installed stopped to connect to MySQL.
In the EC2 log the error message  is:
3 13:46:01 ip-172-31-13-65 web: An unhandled exception has occurred while executing the request.
May  3 13:46:01 ip-172-31-13-65 web: System.NotSupportedException: Character set 'utf8mb3' is not supported by .Net Framework.
On MySQL istance we tried to modify from AWS parameters to:
character_set_client     | utf8mb4            |
| character_set_connection | utf8mb4            |
| character_set_database   | utf8mb4            |
| character_set_filesystem | binary             |
| character_set_results    | utf8mb4            |
| character_set_server     | utf8mb4            |
but nothing changed and the APP still do not connect.
Any suggestion?
Thanks

Accepted Answer

Hello,

As per your recent comment if you could not change the connector version then other solution would be to not use utf8mb3, use utf8mb4 instead if it is supported by your application(Please test it in Non-prod first). Use below query to identify columns with said character set.
```
SELECT table_schema,  table_name, column_name, character_set_name
 FROM INFORMATION_SCHEMA.COLUMNS 
where CHARACTER_SET_NAME = 'utf8mb3'
and TABLE_SCHEMA = 'schema_name';
```
Also check if default character set of any of the database is utf8mb3, you should also change that.
```
SELECT SCHEMA_NAME,DEFAULT_CHARACTER_SET_NAME
  FROM INFORMATION_SCHEMA.SCHEMATA
  WHERE DEFAULT_CHARACTER_SET_NAME = 'utf8mb3';
```

Answer

Hello,

This is a know MySQL client(Connector/Net) issue, from MySQL 8.0.29 onward MySQL server uses utf8mb3 rather than utf8, if you are running a old version MySQL connector/NET then it knows "utf8" and "utf8mb4" character sets but have no idea about "utf8mb3".

MySQl 8.0.29 release notes:
[+]https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-29.html

Please check the MySQL connector version you are using on the application end and test after updating it to latest version.

Hope it helps!

Amazon RDS for MySQL is deprecating minor versions 8.0.31, 8.0.29 and 8.0.28 on March 29, 2024

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