Forum Discussion

schneiw's avatar
schneiw
Advocate IV
1 year ago
Solved

Lakehouse high CU usage, unknown source

Hi Can anyone please help me understand what is causing this high usage. The ratio between seconds and CU's consumed seems very skewed, and I do not know what is causing it. Here are some screenshot...
Lakehouse
  • schneiw's avatar
    schneiw
    1 year ago

    Support finally got back to me with this reply. They admitted to it being a backend Microsoft issue, but no word on how and if they would be fixing it or if I would be reinbursed the lost CU's. The abbreviated 'DMS' is for Data Movement Services:

     

    The increased CU usage was attributed to a disabled file system (FS) on the DMS side, which resulted in a significant number of “GetBlobProperties” API calls from DMS to the One Lake Client (OLC). This led to the observed spike in CU usage. After the FS was re-enabled on July 29th, CU usage decreased accordingly.

     

    The spike occurred on 07/18 and subsided on 07/29, aligning with the period when the FS was disabled and subsequently re-enabled on the DMS side, which reduced the number of calls from DMS to OLC.

schneiw's avatar
schneiw
Advocate IV
1 year ago

Thanks, I was trying in the wrong place for support ticket! I did successfully log a ticket and will update this post with Microsoft's findings.

  • spaceman127's avatar
    spaceman127
    Super User
    1 year ago

    I checked it on a lakehouse that is practically not used at all. The CU is virtually zero.

    I think opening a ticket with MS is also the right way to go.

     

    Best regards

  • zzthatcher's avatar
    zzthatcher
    Advocate I
    1 year ago

    I am having the same issue on the same timeline. It is not resolved.

     

    The dramatic increase for me came from BCDR operations on lakehouses with shortcuts. These did not used get charged for BCDR before Saturday and now we are seeing a dramatic increase in CU usage. Nearly a quarter of our capacity is committed to these new BCDR operations as of Saturday. 

    • schneiw's avatar
      schneiw
      Advocate IV
      1 year ago

      I had a call with support today, they are investigating and I will update their findings. The support tech said they had never seen spikes like this before so hopefully they can correlate to a change that they made to the backend.

      • v-prasare's avatar
        v-prasare
        Community Support
        1 year ago

        Hi schneiw,

        We are following up once regarding your query. Could you please confirm if the issue has been addressed through the support ticket with Microsoft?

         

        zzthatcher, spaceman127, lbendlin, Thanks for your prompt response

         


        If the issue has been resolved, we kindly request you to share the resolution or key insights here to help others in the community. 

         

         

        Thanks,

        Prashanth

        Microsoft Fabric Community Forum