MySQL Connection Error for TDV

Since Zapier is coming in from outside your instance, a possible cause of your problem is the security group for your instance. Most ports on EC2 instances (except the SSH port) are normally blocked by default unless you explicitly open them.

So you would need to open the mysql port 3306 on your instance up to the ip address Zapier is coming in from. (preferably you would not open it up to everyone in the world.)

See Using Amazon RDS/EC2 on the Zapier site, starting from the section where it says Can't Connect to My Database. They continue on to provide specific instructions for the security group settings.

You will also probably need to grant permission on the database using the mysql GRANT command to the user coming in from the Zapier ip address.

Something like this should work :

GRANT ALL PRIVILEGES
ON mydb.*
TO 'user'@'54.86.9.50'
IDENTIFIED BY 'newpassword';

Or you can allow that user to come in from any ip adress like this:

GRANT ALL PRIVILEGES
ON mydb.*
TO 'user'@'%'
IDENTIFIED BY 'newpassword';

(Incoming requests would still be limited to Zapier ip addresses due to the security group settings.)

It is unlikely that a named instance is running on port 1433, unless you explicitly set it as such. I also suspect that SSMS is using shared memory (if local) or named pipes (if remote), unlike JDBC which is using TCP/IP (and I don't know how to set JDBC to use a different protocol).

From this documentation, it seems your connection string should be:

jdbc:sqlserver://MS8AT09;instanceName=AT09;...

With no port designation. You could also try using the IP address instead of the name, in case name resolution is hampered for some reason.

Please check what port the instance is running on (look at SQL Server Configuration Manager)...

...and confirm your connection string does not hard-code a port that is different (JDBC might ). Do not hard-code the dynamic port, because it may not be the port used next time SQL Server starts. From Microsoft's documentation:

We recommend that the port number always be specified, as this is more secure than using sqlbrowser.

So, you may want to set your named instance to run on a specific port number, instead of using a dynamic port (the default), and then hard-coding that port number in the JDBC connection string. You can use the one that the instance was using dynamically, since you know it isn't in use by anything else. Also see KB #823938. So your connection string would become (assuming you used port 56737):

jdbc:sqlserver://192.168.0.65;instanceName=AT09;port=56737;...