Are data replicated when onboarding an existing party in another participant node?

Hi team,

If a party Alice who has been enabled in a participant node A is onboarded on a new participant node B. Will all the contracts related to the party Alice replicated to the new participant node B?

Thanks and regards,
Jean-Paul

The data is not automatically replicated. You need to manually export & import the ACS. Take a look at the documentation on multi-hosted parties for more info on this step.