Why loading data from dataflow requires Gateway

[Frostwind]

Hello everyone.

On our PPU workspace we have a set of dataflows loading and processing data from our SQL database. This part works correctly: requests go through gateway, we see SQL requests in SQL profier, gateway does its work too as I can see by CPU and processes list.

Additionally we have datasets, that collect processed data from the dataflows on the same workspace.

When the datasets load data from the dataflows I see that no SQL requests go to the database, but our On-Premise Gateway shows high CPU load. 

When I open Gateway and cloud connections settings of the dataset, I see a note:

You don't need a gateway for this dataset, because all of its data sources are in the cloud, but you can use a gateway for enhanced control over how you connect

But if I try to map datasource to Cloud Connections (below), during refresh it gives error:

Refresh failed because this dataset requires a gateway. Please select a gateway from dataset settings.

Question: Is that correct behaviour? Am I missing some settings here? 

[GilbertQ]

Hi @Frostwind 

Yes that is correct because if you are using a combination of cloud and on-premise connections it then routes all the traffic through the gateway.

This is by design.

[Frostwind · Accepted solution]

Seems like I found the issue.

The error message was misleading. Dataset doesn't require gateway. When you switch to cloud connection, you need to reauthenticate at Data source credentials below. For some reasons Power BI was not able verify credentials there, but the warning message is visible only if you open that setting, so I didn't see it.

Now it works through direct connection

[Frostwind]

@GilbertQ, thank you for the response.

Can I clarify one more moment? What do you mean by a combination of cloud and on-premise connections? Aren't dataflows and datasets both on the cloud? Datasets connect only to dataflows, they don't have any other connections. And they both are in the same workspace