RapidMiner jTDS Network error: IOException: Connection refused: connect

Network error: IOException: Connection refused: connect

There a quite a number of reasons why you might get this error. However, assuming the following:

1. You're using jTDS to connect to connect to a SQL Server instance 
2. You're trying to use Windows authentication (not passing SQL Server credentials)
3. You've installed the ntlmauth.dll library (link to download page). 

Confirm the following via the SQL Server Configuration manager (Start->Run->SQLServerManager11.msc):

1.  The TCP/IP protocol is enabled.

2.  Your SQL Server instance is listening on the SQL Server default port of 1433 -or- you have entered the correct port in your jTDS configuration/connection string.

3.  The SQL Server Browser service is running.

If you confirmed and/or changed your configuration based on the above recommendations, restarted your SQL Server instance, and still cannot successfully connect, refer to the jTDS SourceForge FAQ page.