Pipeline blob storage event trigger filters not being recorded or used

[david-shattuck]

I created a trigger for a data pipeline meant to notice when csv files were created in a specific folder in my blob storage account (first screenshot). Afterwards, my filters apparently had no effect and the pipeline was being triggered whenever any file was added to any folder (and regardless of what type of file it was), causing the pipeline to run and fail many times.

I cannot seem to find anywhere in the Fabric UI to view/edit these trigger filters, so I went into the Azure portal to view the event subscription itself. In the filters tab I can see there are no filters set (second screenshot). When I try to add the subject filters manually here, I get an error message saying some fabric header is missing from the uri (third screenshot).

After three attempts to do this with always the same result (the filters not being saved or used), I've set up a workaround where the first step in the pipeline is an If-check to stop the pipeline if the file is in the wrong place or is of the wrong type, but I'm expecting many files to be coming through this storage account and I don't want to be unnecessarily firing off this pipeline hundreds of times per day.

Is there something incorrect about the way I have set up the filters that explains why they are not having any effect? And/or am I looking in the wrong place in Azure to see them? And is there somewhere in the Fabric UI to edit/view them?

Adding the filters during trigger creation

filters don't existfilters can't be added

[v-karpurapud]

Hi @david-shattuck 

We have not yet received a response regarding your query. Could you please confirm if your issue has been resolved? If not, kindly provide additional details so we can offer further assistance.

Thank you

[v-karpurapud]

Hi @david-shattuck 

I wanted to check if you’ve had a chance to review the information provided. If you have any further questions, please let us know. Has your issue been resolved? If not, please share more details so we can assist you further.

Thank You.

[v-karpurapud]

Hi @david-shattuck 

Thank you for submitting your question to the Microsoft Fabric Community Forum, and thanks to @AmiGarala  for offering helpful suggestions.

Could you let us know if the suggested solution resolved your issue?If you still need help, please share more details so we can assist you further.

Thank you.

[AmiGarala · Accepted solution]

Hi @david-shattuck,

Thanks for sharing the detailed screenshots, that makes the issue very clear.

From what you’ve described, this doesn’t look like a misconfiguration on your side. A few important points:

1. Filters not persisting – The fact that filters show up in the Fabric UI during trigger creation but do not appear in the Azure portal event subscription strongly suggests that the filter metadata isn’t being passed/saved correctly by Fabric when creating the event subscription.

2. Known limitation / bug – Currently, Fabric pipeline event triggers for Blob storage have limited support for subject filters. In some cases, the filters are ignored and the subscription defaults to firing on all BlobCreated events. This matches what you are experiencing.

3. Workaround – You’ve already set up an If-condition activity in your pipeline to stop unnecessary runs, which is the recommended workaround until this is fixed. Another option is to use advanced filters in the Azure Event Grid subscription directly (but as you saw, Fabric doesn’t always allow editing these from its side).

4. Support escalation – Since this results in hundreds of unwanted pipeline triggers, I would suggest raising a Microsoft Fabric support ticket. Include your session ID and time of trigger creation so the engineering team can verify why the filters aren’t getting persisted in the backend.

At this stage, your setup looks correct, and the issue is more likely Fabric not applying the filters when creating the Event Grid subscription.

Hope this helps. Please mark this as a solution if you find it useful.