jdbc connector receives TCP/IP error against the warehouse

I'm facing the same issue from Synapse Spark. The problem is due to Fabric's forced usage of Redirect connections for Azure hosted compute. Local Spark works fine, cloud does not.

The error:

2024-09-07 22:59:22,622 INFO ApplicationMaster [shutdown-hook-0]: Unregistering ApplicationMaster with FAILED (diag message: User class threw exception: com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host ....pbidedicated.windows.net\...dw (redirected from ...-....msit-datawarehouse.fabric.microsoft.com), port 1433 has failed. Error: "null. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".
	at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:234)
	at com.microsoft.sqlserver.jdbc.SQLServerException.ConvertConnectExceptionToSQLServerException(SQLServerException.java:285)
	at com.microsoft.sqlserver.jdbc.SocketFinder.findSocket(IOBuffer.java:2462)
	at com.microsoft.sqlserver.jdbc.TDSChannel.open(IOBuffer.java:668)
	at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:2695)
	at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:2362)
	at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:2213)
	at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:1276)
	at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:861)
	at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:677)
	at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:189)

 The code (scala):

val server = driverOpts.FabricSqlKeepAliveDriver.Source.SqlServer.Server
val domain = driverOpts.FabricSqlKeepAliveDriver.Source.SqlServer.Domain
val port = driverOpts.FabricSqlKeepAliveDriver.Source.SqlServer.Port
val database = driverOpts.FabricSqlKeepAliveDriver.Source.SqlServer.Database
val tables = driverOpts.FabricSqlKeepAliveDriver.Source.SqlServer.Tables
val jdbcUrl = s"jdbc:sqlserver://${server}.${domain}:${port};database=${database}"

val connectionProperties = new java.util.Properties()
connectionProperties.setProperty("accessToken", accessToken)
connectionProperties.setProperty("encrypt", "true")
connectionProperties.setProperty("trustServerCertificate", "false")
connectionProperties.setProperty("hostNameInCertificate", s"*.${domain}")
connectionProperties.setProperty("loginTimeout", "30")

DriverManager.registerDriver(new com.microsoft.sqlserver.jdbc.SQLServerDriver());

// This will throw in Azure Synapse Spark
val connection: Connection = DriverManager.getConnection(jdbcUrl, connectionProperties)

Local:

Azure:

In regular Azure SQL, you can force Proxy connections to solve this problem:

Azure SQL Database connectivity architecture - Azure SQL Database and Azure Synapse Analytics | Microsoft Learn

Fabric doesn't have a solution yet, unless someone can comment on this thread.