BI Aggregation, different source connections

Hi Lin,

Sorry i should have posted the tests below in the original post. There is already a gateway set up so I think that message is a bit of a red herring we are getting. Prior to posting i testing this:

1. Published to service the model with a connection to the HDInsight Spark Cluster as direct query. This worked

2. Published a model with 2 imported tables from Hive ODBC. This worked 

3. Published a composite model with a spark table set as direct query and 2 hive imported tables (tests 1 & 2 above) but no aggregations set up between Spark and Hive.  All data sources worked independently

4. Published a composite model with a spark table set as direct query and 2 hive imported tables and aggregations set up.  This failed with the no gateway available message

5. Published a composite model with Spark table set as direct query and also a table imported from Spark.  Aggregations were were set up and works in the service.

As all of the 5 tests work in Power BI desktop and only test 4 fails in the service. I also noticed on test 4 that when in the service I have no ability to set up the credentials as it is greyed out, although they are set in the desktop 

The question  therefore is, do you know if there is a restriction on the BI service, that means when using aggregations the direct query source and  the imported aggregated sources have to be from the same source i.e. Spark & Spark or Hive & Hive but not a combination of Spark & Hive? 

Thanks