Microsoft has released a new version of their SQL Server JDBC driver:
Table-Valued Parameters (TVPs)
TVP support allows a client application to send parameterized data to the server more efficiently by sending multiple rows to the server with a single call. You can use the JDBC Driver 6.0 to encapsulate rows of data in a client application and send the data to the server in a single parameterized command.
There are a couple of interesting features in this driver which could help your Hadoop cluster play nice with SQL Server.