ALTER INSTANCE
The ALTER INSTANCE
statement is used to make changes to a single TiDB instance. Currently, TiDB only supports the RELOAD TLS
clause.
RELOAD TLS
You can execute the ALTER INSTANCE RELOAD TLS
statement to reload the certificate (ssl-cert
), the key (ssl-key
), and the CA (ssl-ca
) from the original configuration path.
The newly loaded certificate, key, and CA take effect on the connection that is established after the statement is successfully executed. The connection established before this statement execution is not affected.
When an error occurs during reloading, by default, this error message is returned and the previous key and certificate continue to be used. However, if you have added the optional NO ROLLBACK ON ERROR
, when an error occurs during reloading, the error is not returned, and the subsequent requests are handled with the TLS security connection disabled.
Syntax diagram
AlterInstanceStmt:
- AlterInstanceStmt
- InstanceOption
AlterInstanceStmt ::=
'ALTER' 'INSTANCE' InstanceOption
InstanceOption ::=
'RELOAD' 'TLS' ('NO' 'ROLLBACK' 'ON' 'ERROR')?
Example
ALTER INSTANCE RELOAD TLS;
MySQL compatibility
The ALTER INSTANCE RELOAD TLS
statement only supports reloading from the original configuration path. It does not support dynamically modifying the loading path or dynamically enabling the TLS encrypted connection feature when TiDB is started. This feature is disabled by default when you restart TiDB.