According to this page: https://spark.apache.org/sql/ you can connect existing BI tools to Spark SQL via ODBC or JDBC:
I don't mean Shark as this is basically EOL:
It is for this reason that we are ending development in Shark as a separate project and moving all our development resources to Spark SQL, a new component in Spark.
How would a BI tool (like Tableau) connect to shark sql via ODBC?
With the release of Spark SQL 1.1 you also have thrift JDBC driver see https://spark.apache.org/docs/latest/sql-programming-guide.html#distributed-sql-engine