If the primary node in the Orchestration Server cluster fails, you should see a job restart on another Orchestration Server in the cluster. The job must have been flagged as restartable. For more information, see Section 1.6, Testing the Failover of the Orchestration Server in a High Availability Grid.
When the Orchestration Server fails over to a new node, the Orchestration Agents reauthenticate with the new Orchestration Server instance.