Why is there CU usage while no activity running?

Hi Jerome22,

I'm having the same issue.  I'm trialling Fabric (on an F8) and the week before last I saw that I seemed to be using a lot of CUs for background tasks when I had nothing running.  Last week I decided not to use Fabric at all to eliminate completely anything that I was doing, I had no scheduled jobs running and no queries being made to my Lakehouse’s, Warehouses or Dataflows, no refreshes of Dataflows or data models and I didn’t view any reports that would be using my Fabric data either.  The only thing I had was 5 mirrored dbs (all MS documentation that I've read states that these should not use CUs to keep in sync, should only be using CUs when you query them, unless I’ve misinterpreted anything) and I have shortcuts setup in my Lakehouse’s (again these should not be using CUs as no data is being copied, they are shortcuts).  As I said, none of my dataflows or pipelines that take the data from the Lakehouse, carry out transformationss and land the data in my Warehouse are running or scheduled to run, yet all last week every day I seemed to be using between 15% and 20% of my CUs on background tasks.  Last Wednesday I had supposedly used 96,441 CUs, on Thursday 140,000 and on Friday 110,000 all when I'm doing nothing and have nothing running.

I'm really liking Fabric and all the new capabilities that are available but I'm really not liking that 15 to 20% of my daily CUs on an F8 are being used when I'm not doing anything.  I'm already quite concerned that when I have been running jobs that they are using a lot of CUs and this is only a small amount of what I would like to have running on Fabric.

I hope that you got some answers or its resolved for you.  I will also be raising an MS support ticket.