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I got the following error when I ran SQL on the notebook:
Diagnostic ID: 3d62864c-dc22-4d20-9b33-304aba1aac98
Timestamp: 2026-05-26T20:00:31.978Z
Message: [object CloseEvent]
JSON
{
"type": "close",
"timeStamp": 16735.19999998808,
"code": 1000,
"reason": "{\"reason\":\"Session error or stopped.\",\"state\":\"session-completed\"}",
"wasClean": false,
"target": {
"url": "wss://pbipcanc3-canadacentral.pbidedicated.windows.net/webapi/capacities/0a466b55-b214-4517-a99d-6128acb2e811/workloads/Notebook/Data/Automatic/api/workspaces/1d6102c8-0bd2-499b-a84f-e32baee5b879/artifacts/1ab656ca-2ea5-4184-9296-59aefc0b23a2/jupyterApi/versions/1/api/kernels/380cca33-3c48-4c1d-a0f5-5e1ad853c8df/channels?token=dummy_token&session_id=48c075f2-5d1d-4e80-a6cc-832c86633937",
"readyState": 3,
"protocolsProfile": [
7,
4427
]
},
"currentTarget": {
"url": "wss://pbipcanc3-canadacentral.pbidedicated.windows.net/webapi/capacities/0a466b55-b214-4517-a99d-6128acb2e811/workloads/Notebook/Data/Automatic/api/workspaces/1d6102c8-0bd2-499b-a84f-e32baee5b879/artifacts/1ab656ca-2ea5-4184-9296-59aefc0b23a2/jupyterApi/versions/1/api/kernels/380cca33-3c48-4c1d-a0f5-5e1ad853c8df/channels?token=dummy_token&session_id=48c075f2-5d1d-4e80-a6cc-832c86633937",
"readyState": 3,
"protocolsProfile": [
7,
4427
]
},
"isTrusted": true
}
Additional info: InstanceId: e5d99308-5127-4d09-b939-7dfa5ce9892d
Hi @Krishsaba
What I also recommend is to look to see if you can optimize your SQL code in your notebook so that it can run faster.
Hi @Krishsaba,
This is a capacity limit.
What size capacity do you have?
Are you using the defauly spark pools?
For small capacities like F2 or F4, the default pool with medium nodes is too big, so you will need to create a custom pool using small nodes and no autoscale.
Proud to be a Super User! | |
Hi @Krishsaba ,
This error means your Fabric capacity has hit the concurrent Spark jobs limit. It's a SKU-level throttling issue, not a problem with your code.
Learn : https://learn.microsoft.com/fabric/data-engineering/spark-job-concurrency-and-queueing
I see this:
Activate high concurrency: https://learn.microsoft.com/es-es/fabric/data-engineering/configure-high-concurrency-session-noteboo...
1. Review and cancel active jobs
Go to Workspace Settings → Data Engineering/Science → Spark settings → Jobs and cancel any non-critical Spark jobs. There are often "zombie" notebook sessions consuming slots without doing anything useful. https://learn.microsoft.com/fabric/data-engineering/job-concurrency-queue-monitoring
2. Wait and retry
If the load is temporary (end of day, scheduled pipelines firing at the same time), waiting a few minutes and retrying is usually enough. The timestamp is 20:00h, which may coincide with scheduled workloads.
3. Check the Monitor Hub
Filter by "Running" status and check how many Spark jobs are active simultaneously. You can also see if there's contention from other workspaces on the same capacity (noisy neighbor scenario).
More:
https://learn.microsoft.com/fabric/data-engineering/job-queueing-for-fabric-spark .
https://learn.microsoft.com/fabric/data-engineering/autoscale-billing-for-spark-overview
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Thank you!
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