Data is not sync from Member to Hub db.

Question

Data is not sync from Member to Hub db.

Akash Patel 0

I already configured column and table in sync group but data is only updating when I execute SQL query manually but If I performed scenario from .NET application then sync is not working (.NET Framework with EF). I checked that azure sql trace and found that insert query but nothing updated in HUB db table. I execute the query on Member DB table.

Here is the insert query i can see in SQL trace (from HUB db Server):

declare @p3 DataSync.Client_dss_BulkType_98087373-6da6-4ec4-88d9-31992cc20798

insert into @p3 values('BC3BD3A3-132B-4F93-8076-93E0332D3D19','A87E9A3A-E4A0-4121-BE07-DFB0E9D245BC',N'VendorID',N'Demo_Provider_AP_TEST222',N'http://localhost.com',NULL,NULL,N'V2',NULL,NULL,NULL,NULL,NULL,NULL,1,0,0,NULL,'2026-11-19 21:49:24.0230000',N'confidential',N'native',N'Created via Dev Portal ',1,'2025-11-19 21:49:24.0230000',NULL,'2025-11-21 16:53:08.6770000',NULL,2,0,N'DowntownClient',N'Provider',NULL,40476678,1,39747042,1)

exec [DataSync].[Client_dss_bulkupdate_98087373-6da6-4ec4-88d9-31992cc20798] @sync_min_timestamp=1327624444,@sync_scope_local_id=21,@changeTable=@p3

I think update triggered is fired that's why it is showing insert query on SQL trace so apart from this, Is there thing I need to verify ?

Note: Biredirectional sync configured.

2 answers

Your answer

Answer 1

It sounds like you are experiencing issues with data synchronization from the Member database to the Hub database in Azure SQL Data Sync. Here are some things you can verify:

Check for Circular References: Ensure that there are no circular references in your sync groups, as these can cause sync issues. Any row that is synced by one sync group should not be synced by another.
Primary Key Requirement: Verify that all tables involved in the sync have a primary key defined. If the primary key is changed, it can lead to data loss or sync failures.
Data Types and Constraints: Make sure that the data types of the columns being synced are compatible and that there are no constraints (like CHECK constraints) that could prevent the data from being inserted into the Hub database.
Sync Status: Check the status of your sync group in the Azure portal. If it is in a processing state, it may need to be reset. You can create a post in the Microsoft Q&A question page for Azure SQL Database to have the sync group status reset.
SQL Trace: Since you mentioned that you see an insert query in the SQL trace, ensure that the insert operation is not being blocked by any triggers or constraints in the Hub database that might prevent the data from being updated.
Manual Testing: If possible, try to manually insert data into the Hub database to confirm that it can accept data without issues. This can help isolate whether the problem is with the .NET application or with the sync configuration itself.
EF Configuration: Review your Entity Framework configuration to ensure that it is set up correctly to handle the data sync operations. Sometimes, the way EF manages context and transactions can affect how data is sent to the database.

By checking these areas, you may be able to identify the root cause of the synchronization issue you are experiencing.

References:

Answer 2

Alberto Morillo 35,401 MVP Volunteer Moderator

Try to disable key constraints on the tables involved temporarily to see if that allows the INSERT statement to be successful.

In addition, as you can read here, if your .NET code uses anything like: SqlBulkCopy, A “BulkInsert” extension/library or a custom BULK INSERT command then by default, triggers don’t fire unless the FIRE_TRIGGERS option is used. Data Sync relies entirely on those insert/update/delete triggers to track changes.

Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-11-26T08:22:49.08+00:00

Hi Akash Patel •,

We haven’t heard back from you regarding your last response, Alberto Morillo •and I just wanted to check in to see if you’ve found a resolution yet. If so, please share your solution with the community, as it could be helpful to others. If the issue is still unresolved, feel free to provide more details, and we’ll do our best to assist you.
Akash Patel 0 Reputation points

2025-11-26T20:59:13.4433333+00:00

I tried after disabling constraint but it won't work. Other tables works fine in same sync group but it only affect one table. Even insert operation works fine but when I update values then it is not working.
Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-11-27T05:35:31.3266667+00:00
Hi Akash Patel •,

Thanks for the response.

This usually happens when the update trigger for this specific table is not firing or is not capturing changes properly. Azure SQL Data Sync relies on these triggers to track updates. If the trigger is missing, disabled, or corrupted, updates will not sync, even though inserts work fine.

Next steps we recommend:

Check the update trigger on the member database (<YourTableName>_dss_update_trigger) to ensure it exists and is enabled.

Verify the tracking table (DataSync.<YourTableName>_dss_tracking) to see if updates are being recorded.

Review the application update behavior — bulk operations or “no-op” updates may not fire triggers.

Recreate sync metadata for the table if the trigger is corrupted, by removing it from the sync group and adding it back.

I hope this information helps. Please do let us know if you have any further queries.
Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-11-28T11:47:25.9933333+00:00

Hi Akash Patel •,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-12-01T04:58:21.46+00:00

Hi Akash Patel •,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Akash Patel 0 Reputation points

2025-12-01T07:02:27.61+00:00

Thanks for your response. We tried all steps that you mentioned but didn't work but we notice that below table (@changed) not filling any value
SP: [DataSync].[Client_dss_bulkupdate_<UniqueIdentifier>]
Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-12-02T16:29:44.22+00:00
Hi Akash Patel •,

Thank you for confirming the details.

Based on your observation that the @changed table remains empty, this usually means the UPDATE branch of the sync process isn’t firing because no rows meet the conditions in the stored procedure. This can happen if:

The update trigger or tracking table isn’t recording changes correctly.

The sync metadata filters in the procedure exclude the rows.

Schema changes after provisioning caused the sync objects to become out of sync.

Recommended next steps:

Verify that the update trigger (<YourTableName>_dss_update_trigger) exists and is enabled.

Check the tracking table (DataSync.<YourTableName>_dss_tracking) for the rows you’re updating.

Run the Azure SQL Data Sync Health Checker to confirm all system objects are healthy.

If issues persist, remove the table from the sync group and add it back to recreate metadata.

I hope this information helps. Please do let us know if you have any further queries.
Mahesh Kurva 10,435 Reputation points Microsoft External Staff Moderator

2025-12-03T17:38:34.83+00:00

Hi Akash Patel •,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help
Akash Patel 0 Reputation points

2025-12-04T00:10:02.0066667+00:00

We removed the primary and reference table from sync group and add it again. Noticed one thing that few of the reference tables data are updated but primary table data is still not updated.

I can see below log like but changes not applied on HUB db.
Sync completed successfully in 1.91 seconds. Upload: 5 changes applied Download: 0 changes applied

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Data is not sync from Member to Hub db.

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