Error occurred while executing a query

20/03/2023 22:19:14 [http-nio-8080-exec-2] WARN  o.a.g.e.AuthenticationProviderFacade - The "mysql" authentication provider has encountered an internal error which will halt the authentication process. If this is unexpected or you are the developer of this authentication provider, you may wish to enable debug-level logging. If this is expected and you wish to ignore such failures in the future, please set "skip-if-unavailable: mysql" within your guacamole.properties. 

20/03/2023 22:19:14 [http-nio-8080-exec-2] ERROR o.a.g.rest.RESTExceptionMapper - Unexpected internal error:  

20/03/2023 22:19:14  ### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 

20/03/2023 22:19:14  The last packet successfully received from the server was 168 milliseconds ago.  The last packet sent successfully to the server was 160 milliseconds ago. 

20/03/2023 22:19:14  ### The error may exist in org/apache/guacamole/auth/jdbc/user/UserMapper.xml 

20/03/2023 22:19:14  ### The error may involve org.apache.guacamole.auth.jdbc.user.UserMapper.selectOne 

20/03/2023 22:19:14  ### The error occurred while executing a query 

20/03/2023 22:19:14  ### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 
   
20/03/2023 22:19:14  The last packet successfully received from the server was 168 milliseconds ago.  The last packet sent successfully to the server was 160 milliseconds ago.