I experience the same situation.

Caused by: java.sql.SQLException: [Databricks][DatabricksJDBCDriver](500593) Communication link failure. Failed to connect to server. Reason: HTTP retry after response received with no Retry-After header, error: HTTP Response code: 503, Error message: Unknown.

I've attempted a retry on the client side via failsafe library, but this turns out to have the effect of doing a duplicate `INSERT` in case that the failure happens on an `INSERT` statement.

It seems that the error code 500593 is rather signaling that the operation took longer than expected.

I'm just wondering, can this situation be avoided by specifying a longer timeout ?