SQL Workbench /J & Aurora & MariaDB driver getting "could not load system variables" - FIXED!

 Using the 2.7.3 MariaDB java connector with SQL Workbench /J, I was trying to reach my aurora instance but kept getting this error:

could not load system variables

• https://community.dremio.com/t/mysql-source-creation-fails/6738/2
• https://github.com/sysown/proxysql/issues/2523
• https://github.com/sysown/proxysql/issues/2009
• https://stackoverflow.com/questions/63283846/issue-integrating-mariadb-client-with-mysql-db

Finally found an answer here:

• https://jira.mariadb.org/browse/CONJ-824

As per Diego Dupin:

Aurora proxy has a known race condition issue that results in skipping other queries in proxy buffer. connection might be in hang waiting for query response. During authentication, socket has a timeout, that will result throwing the error you describe.

So if `usePipelineAuth` or `useBatchMultiSend` is enable, it might work ... or not. All pipeline options (`usePipelineAuth` and `useBatchMultiSend`) must be disabled when using aurora. Problem has been reported to aurora a few times without correction.

What worked for us was adding this after the DB name 

usePipelineAuth=false&useBatchMultiSend=false

like this:

jdbc:mysql://127.0.0.1:3307/mydbname?usePipelineAuth=false&useBatchMultiSend=false