Failure happened on 'Source' side. Message=The semaphore timeout period has expired,Source=

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Failure happened on 'Source' side. Message=The semaphore timeout period has expired,Source=

Vanaja Kasturi 0

Hi Team,

I am getting this below error while ingesting data from SQL Server to ADLS.While the same pipeline is running in dev environment with much higher data volume(2x).

Failure happened on 'Source' side. ErrorCode=UserErrorWriteFailedFileOperation,'Type=Microsoft.DataTransfer.Common.Shared.HybridDeliveryException,Message=The file operation is failed, upload file failed at path: 'test/VDIST/RDBI_REPORT/RDVDTRANSACTION/RDVDTRANSACTION_20250513.parquet'.,Source=Microsoft.DataTransfer.Common,''Type=System.Data.SqlClient.SqlException,Message=A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.),Source=.Net SqlClient Data Provider,SqlErrorNumber=121,Class=20,ErrorCode=-2146232060,State=0,Errors=[{Class=20,Number=121,State=0,Message=A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.),},],''Type=System.ComponentModel.Win32Exception,Message=The semaphore timeout period has expired,Source=,'

It is a CDC operation.I have tried retrying it multiple times but still same issue persists.Kindly help.

Smaran Thoomu 24,110 Reputation points Microsoft External Staff Moderator

2025-05-15T08:31:37.47+00:00

@Vanaja Kasturi 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.

1 answer

Your answer

Smaran Thoomu 24,110 Reputation points Microsoft External Staff Moderator

2025-05-15T08:31:37.47+00:00

@Vanaja Kasturi 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.

Answer 1

Smaran Thoomu 24,110 Microsoft External Staff Moderator

Hi @Vanaja Kasturi
Thank you for reaching out and for the detailed error message.

The error "The semaphore timeout period has expired" typically indicates a network connectivity issue or transient timeout between your SQL Server and the integration runtime (IR) in Azure Data Factory. While it’s working in dev with a higher volume, the issue in your current environment may be related to:

Possible Causes:

Network latency or instability between the self-hosted integration runtime and the source SQL Server.
Resource exhaustion on the SQL Server or IR machine (CPU/memory/network).
Firewall, VPN, or proxy timeouts affecting long-running data transfers.
Large CDC result sets taking too long to transfer and hitting the OS-level TCP timeout.

Suggested Actions:

Check the SQL Server health (CPU, memory, disk I/O) during the pipeline run.
Review the IR machine’s network performance and logs — ensure it has a reliable and fast connection to the SQL Server.
Split the load: If possible, try partitioning the CDC data or reducing the data batch size to see if smaller chunks succeed.
Set retry and timeout settings: Ensure your linked service and copy activity have retry policies configured. You can also consider increasing timeout values where applicable.

If the issue persists, it may help to:

Test a manual connection from the IR machine to SQL Server (e.g., using SSMS).
Share details like:
- Are you using self-hosted or Azure IR?
- Estimated size of CDC data for this run?
- Whether any recent network or SQL Server changes occurred in this environment?

I hope this information helps. Please do let us know if you have any further queries.

Kindly consider upvoting the comment if the information provided is helpful. This can assist other community members in resolving similar issues.

Vanaja Kasturi 0 Reputation points

2025-05-13T15:04:37.9533333+00:00
Hi @Smaran Thoomu ,

We are using SHIR

Data is approximately 12 GB(we run CDC on t-90 days)

Recently SQL Server IP got changed. But the pipeline was successful the next day after changes. But from today is is giving this issue. Kindly suggest.
Smaran Thoomu 24,110 Reputation points Microsoft External Staff Moderator

2025-05-14T11:29:39.22+00:00
Hi @Vanaja Kasturi
Given that you're using a Self-hosted Integration Runtime (SHIR) and the SQL Server IP was recently changed, it’s possible that the new network route or firewall configuration might be intermittently affecting the stability of long-running connections — especially for large CDC datasets (~12 GB over 90 days).

Based on your update, here are a few suggestions:

Even if the pipeline worked the day after the IP change, intermittent timeouts like "The semaphore timeout period has expired" may indicate unstable network routes or transient latency.

From the SHIR machine, try a continuous ping or telnet test to the new SQL Server IP over port 1433 (or whichever port is used).

ping <SQL_Server_IP> -t telnet <SQL_Server_IP> 1433

Look for high latency or dropped packets.

Sometimes, restarting the SHIR service and verifying the SQL Server's network bindings can help re-establish stable TCP connections after IP changes.

Try breaking the 90-day CDC window into smaller time slices (e.g., 30 days) to reduce payload size per run.

Check if using staging in copy activity helps (especially with Parquet sink).

Confirm with your network team if any firewall session timeouts or proxy idle timeouts might be expiring during long transfers. These often don’t affect small transfers but will interrupt longer ones.

Enable verbose logging in the copy activity to capture more detail about when exactly the timeout occurs.

You may also consider enabling SHIR logs to monitor connection health during the pipeline run.

If the issue persists even after trying the above, it might help to raise a support ticket so the backend team can analyze telemetry in detail.

I hope this information helps. Please do let us know if you have any further queries.

Kindly consider upvoting the comment if the information provided is helpful. This can assist other community members in resolving similar issues.

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Failure happened on 'Source' side. Message=The semaphore timeout period has expired,Source=

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