What Is the Impact of Changing the Authentication Method From OAuth to Service Principal?

Question

Does changing a connection's authentication method from OAuth2 to Service Principal impact incremental syncs or trigger a historical sync?

Environment

Connector: Microsoft Dynamics 365 CRM

Answer

No, changing the authentication method from OAuth2 to Service Principal doesn't trigger a historical sync, as long as the environment, entity set, and query structure remain the same.

Fivetran uses delta tokens for incremental syncs. When we sync an incremental entity for the first time, Dynamics 365 returns a delta token, which we use to fetch changes in subsequent syncs. Changing the authentication method doesn’t automatically invalidate existing delta tokens, so incremental syncs continue as expected.

Before changing the authentication method, ensure that the Service Principal has access to the same entities and data as the OAuth user. If the Service Principal has more restrictive permissions and can't access entities or data associated with existing delta tokens, incremental syncs may fail.