title: Setting up a second connection with AWS Glue to a target RDS/Mysql instance fails
body: <p>I'm trying to setup an ETL job with AWS Glue that should pull data from the production database on RDS/Aurora, run some very light weight data manipulation (mainly: removing some columns) and then output to another RDS/Mysql instance for "data warehouse". Each component is in its own VPC. RDS/Aurora &lt;> AWS Glue works however I'm having hard time figuring out what's wrong with AWS Glue &lt;> RDS/Mysql connection: the error is a generic "Check that your connection definition references your JDBC database with correct URL syntax, username, and password. Could not create connection to database server."</p>
  
  <p>I've been following this step-by-step guide <a href="https://aws.amazon.com/blogs/big-data/connecting-to-and-running-etl-jobs-across-multiple-vpcs-using-a-dedicated-aws-glue-vpc/" rel="nofollow noreferrer">https://aws.amazon.com/blogs/big-data/connecting-to-and-running-etl-jobs-across-multiple-vpcs-using-a-dedicated-aws-glue-vpc/</a> and - I think - I covered all points. To debug, I've also tried to spin a new EC2 instance in the same AWS Glue VPC and subnet and I tried to access the output database and it worked</p>
  
  <p>Comparing the first working connection with the second one doesn't yield to any obvious difference and the fact I was able to connect from an EC2 instance makes me even more confused on where is the problem</p>