What causes UserErrorMySqlConnectionFailed?

The MySQL server is not publicly accessible and no SHIR or VNet integration is configured. The username or password in the ADF linked service is incorrect or has expired. Firewall rules on the MySQL server do not allow inbound connections from the ADF IP range or SHIR host. The MySQL port (default 3306) is blocked by a network security group or corporate firewall. SSL/TLS is required by the MySQL server but not configured in the linked service

How do I fix UserErrorMySqlConnectionFailed?

Test the connection from the linked service settings page in ADF — it will report the specific failure reason.. Verify that the MySQL server allows inbound connections from the SHIR host IP or ADF's Azure IP ranges.. Check the username and password — rotate and update in ADF if credentials have changed.. Confirm the port (3306 by default) is open in the MySQL server's firewall and any network security groups.. If the database is on-premises or in a private network, route traffic through a self-hosted IR.. Check MySQL server SSL settings and enable SSL in the ADF linked service if required.

High severitydata source

Power BI Refresh Error:
UserErrorMySqlConnectionFailed

What does this error mean?

ADF could not connect to the MySQL database — the connection may be blocked by network rules, the credentials may be wrong, or the MySQL server may be unreachable.

Common causes

1The MySQL server is not publicly accessible and no SHIR or VNet integration is configured
2The username or password in the ADF linked service is incorrect or has expired
3Firewall rules on the MySQL server do not allow inbound connections from the ADF IP range or SHIR host
4The MySQL port (default 3306) is blocked by a network security group or corporate firewall
5SSL/TLS is required by the MySQL server but not configured in the linked service

How to fix it

1Test the connection from the linked service settings page in ADF — it will report the specific failure reason.
2Verify that the MySQL server allows inbound connections from the SHIR host IP or ADF's Azure IP ranges.
3Check the username and password — rotate and update in ADF if credentials have changed.
4Confirm the port (3306 by default) is open in the MySQL server's firewall and any network security groups.
5If the database is on-premises or in a private network, route traffic through a self-hosted IR.
6Check MySQL server SSL settings and enable SSL in the ADF linked service if required.

Frequently asked questions

Do I need a self-hosted IR to connect ADF to an on-premises MySQL database?

Yes. ADF cannot connect directly to on-premises databases — you must install a self-hosted IR on a machine in the same network as the MySQL server and route the connection through it.

Official documentation: azure-data-factory