Inexplicable DataflowsStagingWarehouse Load on Capacity

We've recently started seeing entries for "High Scale Dataflow Compute - Warehouse Query" in the Capacity Metric App under Background records.  These were not present a couple months ago and we had a good baseline on the workspace's total compute.  Our dataflows have not changed but suddenly we're seeing a 6% increase in base capacity used under this workspace, attributed to these high-scale entries.

Within this workspace, no dataflows have staging enabled (all queries are italicized), but we are using SQL data destinations so that may be the underlying usage.  I initially thought the billing was just broken out differently in the metric app, but the % base capacity used by the entire workspace has increased by the amount from this line.  It doesn't show under the tooltip for each dataflow either, as NotebookEnjoyer experienced.  The app is no help to narrow this down further.  

Hi NotebookEnjoyer  ,
Thanks for reaching out to the Microsoft fabric community forum.

High Scale Dataflow Compute: You're charged when staging is enabled, based on Lakehouse (Staging storage) and Warehouse (Storage Compute) SQL engine consumption duration.
For high-scale scenarios when staging is turned on queries run on the Lakehouse or Warehouse SQL engine. Each second of compute time uses 6 CU seconds, so longer queries consume more. This could be the reason for high capacity consumption.
If your dataflow uses staging, to find out how much High Scale compute you used, open the Fabric Capacity Metrics App and filter by your Dataflow’s name. Right-click the name, look for High Scale compute in the list of operations, and check the duration.

I hope this information helps. Please do let us know if you have any further queries.
Thank you

Hi NotebookEnjoyer ,
Could you please confirm if the issue has been resolved after raising a support case? If a solution has been found, it would be greatly appreciated if you could share your insights with the community. This would be helpful for other members who may encounter similar issues.

Thank you for your understanding and assistance.

Has anyone been able to determine the source of this issue? A seemingly identical issue started for us on a random Monday and it's continued since then. I'm working with Microsoft support but we haven't found a cause yet.

Using the Fabric Capacity Metrics app and the built in time detail feature one of the stagingwarehousefordataflows warehouse objects is being hit 24/7 with a mix of "OneLake Write via Redirect",  "OneLake Write via Proxy", and "High Scale Dataflow Compute - Warehouse Query" system activities hitting the warehouse object every minute - sometimes every 30 seconds.

Nothing in our pipeline changed when this activity started. We have 3 dataflows that run within 5 minutes. Our usage went up around 10% - which is a 150% increase for us.

Hi sviesa​,

Your detail about activity every 30-60 seconds, 24/7, while your three dataflows only run for about 5 minutes, is the key clue. Dataflow refreshes can't produce that pattern, so something other than the refreshes is talking to the staging warehouse. While your support case runs, I would narrow it down with a few elimination tests.

1. Prove it is (or isn't) the dataflows. Pause all three dataflow schedules for a few hours and watch the staging warehouse item in the Capacity Metrics app:

schedules paused, activity continues -> not the refreshes:
                                        something else is polling
schedules paused, activity stops      -> tied to the dataflows:
                                        go to step 2

2. Turn off staging where you don't need it. For simple copy-and-drop-a-column queries landing in a Lakehouse, staging adds a warehouse round trip without benefit. In each dataflow, right-click each query and clear Enable staging, then republish and compare the next day's CU on the staging items.

3. Look for anything querying through the staging artifacts. The "High Scale Dataflow Compute - Warehouse Query" activity every minute looks like a consumer rather than a writer. Things worth checking:

semantic models / reports connected to a dataflow
  (Dataflows connector) with frequent refresh or DirectQuery
Power Automate / Logic Apps flows polling dataflow output
external tools (Excel, notebooks) connected to the dataflow
monitoring scripts calling dataflow or workspace APIs

Consumers connected through the dataflow connector read via the staging warehouse, so a single report on a short refresh interval, or a DirectQuery model, would produce exactly this "every minute" pattern.

4. Give support the timeline. The fact that it started on a specific Monday with no pipeline change is useful evidence:

staging warehouse item name + workspace ID
exact start date of the extra activity
operation names + CU per hour from Capacity Metrics
result of the "schedules paused" test above

So my overall approach would be:

pause dataflow schedules -> does the activity stop?
-> disable staging on simple queries
-> find consumers reading through the dataflow connector
-> share the timeline and test results with support

The pause test alone will tell you within a few hours whether you are looking for a refresh problem or a hidden consumer.

AI-assisted drafting: AI was used to help structure and phrase this response. I reviewed and validated the technical content before posting.