The secondary database (in the SECONDARY ACTIVE state) on node 2 fails.
The Primary database (in the PRIMARY ACTIVE state) on node 1 encounters connection failure to the Secondary database on node 2.
Recovery
In the recovery from the Secondary database failure the Secondary server is restarted. The recovery proceeds automatically as follows:
1 Upon the connection failure, the Primary database on node 1 moves automatically to the PRIMARY UNCERTAIN state, or if the AutoPrimaryAloneparameter is enabled, to the PRIMARY ALONE state.
2 The HAC instance on the Primary database on node 1 concludes that the Secondary database on node 2 has failed.
3 If the Primary database was set to the PRIMARY UNCERTAIN state in step 1, HAC sets it now to the PRIMARY ALONE state.
4 In parallel with the above task, the HAC instance on the Secondary database on node 2 restarts the Secondary database, which enters the SECONDARY ALONE state.
5 The HAC instance on the Primary database on node 1 initiates the process of connecting the Primary and Secondary database.
6 A catchup is made.
Optionally, the connection process includes a netcopyoperation from the Primary database to the Secondary database.