The primary database (in the PRIMARY ACTIVE state) on node 1 fails.
The secondary database (in the SECONDARY ACTIVE state) on node 2 encounters connection failure to the primary database on node 1.
Recovery
In the recovery from the Primary database failure the Secondary server replaces the Primary server. The recovery proceeds automatically as follows:
1 Upon the connection failure, the Secondary database on node 2 moves automatically to the SECONDARY ALONE state.
2 The HAC instance on the Secondary database on node 2 concludes that the Primary database on node 1 has failed and sets the Secondary database on node 2 to the PRIMARY ALONE state.
3 In parallel with the above task, the HAC instance on the Primary database on node 1 restarts the Primary database, which enters the SECONDARY ALONE state.
4 The HAC instance on the Secondary database on node 2 initiates the process of connecting the Primary and Secondary database.
5 A catchup is made.
Optionally, the connection process includes a netcopy operation from the Secondary database on node 2 to the Primary database on node 1.