topic EventHouse UpTime operation CU increased? in Data Engineering

EventHouse UpTime operation CU increased?

Tröttöröö — Thu, 09 Oct 2025 14:07:16 GMT

Hi,

Since yesterday there have been a massive increase in CU consumption in EventHouse UpTime operations. No changes have been done the Eventhouse setup. The data volume or quality haven't changed. The Eventhouse is running in Sweden Central.

Any ideas?

Re: EventHouse UpTime operation CU increased?

AntoineW — Thu, 09 Oct 2025 15:47:19 GMT

Hello @Tröttöröö,

Here's some action you can do to check if it's normal :

Use the Capacity Metrics App
→ Check detailed CU usage per workload and timepoint.
Review Query Logs
→ Look for changes in query patterns or frequency.
Check EventHouse Settings
→ Confirm timepoint granularity, retention, and partitioning haven't changed.
Open a Microsoft Support Ticket
→ If no internal changes are found, Microsoft can investigate backend operations.

We can definitely see an increase that may need some more investigations !

Hope it can help you,

Antoine

Re: EventHouse UpTime operation CU increased?

lbendlin — Fri, 10 Oct 2025 17:22:42 GMT

We had similar issues and were told to reduce the retention period. Not sure if that is something you can consider.

Re: EventHouse UpTime operation CU increased?

Tröttöröö — Mon, 13 Oct 2025 07:28:19 GMT

Did this end up reducing CU consumption by auto scaling Eventhouse? If so, how immediate was the effect?

Re: EventHouse UpTime operation CU increased?

lbendlin — Mon, 13 Oct 2025 10:53:06 GMT

Not auto scaling. Within 24 hours, as expected.

Re: EventHouse UpTime operation CU increased?

v-aatheeque — Wed, 15 Oct 2025 04:51:38 GMT

Hi @Tröttöröö

Just checking in to see if the previous response helped resolve your issue. If not, feel free to share your questions and we’ll be glad to assist.

Re: EventHouse UpTime operation CU increased?

Tröttöröö — Wed, 15 Oct 2025 05:16:56 GMT

We ended up contacting MS support to investigate this further. It took a MS product manager to figure out, what has happened. Increased CPU consumption had triggered the upscaling. Now we know what to optimize.

I think it would be nice to have a more accurate documentation about the auto scaling logic.

Re: EventHouse UpTime operation CU increased?

lbendlin — Wed, 15 Oct 2025 10:47:15 GMT

That's one of the reasons why we don't use auto scaling.

Re: EventHouse UpTime operation CU increased?

v-aatheeque — Wed, 22 Oct 2025 06:44:00 GMT

Hi @Tröttöröö

Thanks for the update and for sharing those details. Glad to hear Microsoft Support helped identify the root cause.

Could you please confirm if the issue is now fully resolved after applying the optimizations ?