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Hello,
We have encountered issues in our test & production environments today.
No changes have been made to the environments that we are aware off but pipelines in both environments have failed with an "Can't get enough capacity for optimal performance" error.
Some attempts to query the data via SQL have also failed returning the same error.
The issues appears to be transient with some runs succeeding and others failing.
Is there an active issue affecting Synapse or suggestion on how to identify the route cause?
Thank you.
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Hello, there is a "Pre-start Unplanned Maintenance for App Service in North Europe". You can see it the Azure portal > Support > Service Health.
Hi Loris,
Thank you for you help. We have checked the portal and sadly there is nothing there.
I have reviewed a few of the Azure issues dashboard and can't see anything there either, but after the fabric issues that weren't reported in the portals I've become cynical :)
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Hi Tori H The error message "Can't get enough capacity for optimal performance" usually means that your Synapse SQL Dedicated or Serverless pool is under resource pressure. This often happens intermittently during peak usage hours or when queries demand more resources than the backend can allocate.
Even if nothing is showing in Azure Service Health, these errors can still be triggered by internal capacity contention that doesn’t always appear as a public outage.
Here are a few troubleshoot steps:
Investigate Query Failures: If you're using Dedicated SQL Pools, open Synapse Studio > Monitor > SQL Requests or check Log Analytics if it's enabled. Look for failed or long-running queries around the time the issue occurred — errors like resource throttling or wait types such as RESOURCE_SEMAPHORE or IO_COMPLETION often indicate capacity constraints.
Review Workload Management Settings: Sometimes, heavy or long-running queries can block capacity for others, especially if workload groups or priorities aren’t configured. It’s a good idea to review these settings, especially if the issue happens during high-load periods.
For Serverless SQL Pools: If the error is happening in Serverless, try to reduce the data scanned early in the query. Applying filters sooner or switching from CSV/JSON to Parquet format can significantly improve performance and reduce resource load.
Hope this helps. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
Well, I'm experiencing the problem on multiple tenants. However, it's only on one of them that I can find something in the Service Health > History section :
"This notification is for upcoming scheduled maintenance to your Azure App Service instance(s) in the North Europe region. Due to a critical hotfix or urgent update, App Service was not able to provide an advanced notification. Actual upgrade operations will start after 7pm local time in region."
There was also maintenance in the East US region a few days ago, which lasted around 24 hours.
The maintenance in North Europe is still ongoing.
Thank you both for your help.
Loris Thank you for sharing. I've asked a team mate to double check and we have no visibility of that notification. Very strange but unplanned hot fix would explain the issue.
Hopefully the upgrade work worked and the issues will remain gone today.
Tori H We’ve seen that sometimes these kinds of errors are tied to internal capacity constraints or hotfixes rolling out quietly in the background, especially during regional maintenance like the one Loris Roy flagged.
If the issue pops up again, here are a few things worth checking:
In Synapse Studio > Monitor > SQL Requests, take a look at failed or slow-running queries, they can hint at throttling or resource pressure.
If you're not already using Log Analytics, enabling it can help spot trends over time.
And for Dedicated SQL Pools, reviewing workload groups or priorities might help reduce contention during busy periods.
Hope this helps. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.