When the connection to the database has failed there is sometimes no alerting or notification when you attempt to work with the server in the Servers tab, such as expanding the Tables folder. This may be related to use of the generic JDBC driver (or maybe a the specific JDBC driver I'm using) as I can not reproduce it using MySql as the database.

To reproduce:

Set up an ssh tunnel to a server that is running the database

Connect to the database in Data Studio over the tunnel

Kill the ssh tunnel

Expand the Tables folder in Data Studio.

Table expands and is empty

When using MySql as the remote database, there is a "Communication link..." error when you expand the Tables folder.

When using the Hsqldb 2.3.2 driver there is no error.

I was able to find the attached error in the datastudio.log file