Warning: Unable to Validate Log Truncater Configuration for Binary Log Reader

Issue

After configuring log truncation with Binary Log Reader, the following warning appears:

Unable to validate Log Truncater configuration for Binary Log Reader. The recommended Log Truncater is 'SQL_SERVER_AGENT', but the configured Log Truncater is 'FIVETRAN'. Please update the Log Truncater to 'SQL_SERVER_AGENT' for optimal performance and reliability.

Environment

• Connector: SQL Server
• Incremental sync method: Binary Log Reader

Resolution

To resolve this issue, do the following:

1. In Fivetran, go to your SQL Server connection page.
2. Select the Settings tab.
3. Click Edit connection.
4. In the left menu, select Replication.
5. In the Log Truncater drop-down menu, select SQL Server Agent.
6. Click Save & Test.

After saving, verify that the SQL Server Agent service is running and that the CDC capture job is active on your SQL Server instance.

Cause

This issue occurs when Fivetran detects that your SQL Server database contains CDC instances or other SQL replication not created by Fivetran.

When the Log Truncater is set to Fivetran, we advance the replication truncation point after each successful sync. This may disrupt other replication processes that depend on the same truncation point. Using SQL Server Agent lets the native SQL Server CDC capture job manage the truncation point, which is safer when other CDC consumers are present.