If you are unable to connect Sisense with your Redshift data this might be caused by high MTU settings.
Some Amazon EC2 servers are set by default to an MTU value of 9001 (Ethernet "Jumbo frame"), this setting might cause connectivity issues and you will not be able to connect Sisense with your Redshift data. What you will see when trying to connect to Redshift is a none responsive connection causing The import-data dialog box to hang.
In order to solve this, you will need to change the MTU settings to 1500 using the following command in your CMD:
1. From your start menu, run the command prompt by typing 'cmd' and 'enter'.
2. Copy and paste the following command:
netsh interface ipv4 set subinterface "Ethernet" mtu=1500 store=persistent
3. Hit Enter and restart your Amazon instance.
4. Run the ElastiCube Manager again and import the Redshift data.
For more information please see the following link: http://docs.aws.amazon.com/redshift/latest/mgmt/connecting-drop-issues.html
If you still encounter issues wit the above, please don't hesitate to submit a support request.