The following table describes the possible scenarios in a high availability environment.
| Scenario | System action | User action | 
|---|---|---|
| PostgreSQL database is down | The primary Configuration Agent tries to start it up. | You can perform a manual failover, as described in Failing over Control-M/Server and PostgreSQL database server to secondary. | 
| Oracle/MSSQL database is down | An automatic failover does not occur. | 
 | 
| Primary crashes (PostgreSQL) | 
 | You can perform a manual failover, as described in Failing over Control-M/Server and PostgreSQL database server to secondary. | 
| Primary crashes (Oracle/MSSQL) | An automatic failover occurs, based on the conditions described in Automatic failover. | 
 | 
| Shared directory is not available (PostgreSQL) | Manual failover is disabled. | 
 | 
| Reconnecting Control-M/Server to Control-M/EM after a failover/fallback of Control-M/Server | After a secondary Control-M/Server is installed, Control-M/EM is provided with the secondary host. If there is a disconnection between Control-M/EM and Control-M/Server, a check is performed to see if Control-M/Server has failed over to the secondary (or primary if it is a fallback). | N/A | 
| Reconnecting Control-M/EM clients | After the CCM or Control-M GUI connects to the GUI server or CMS, the secondary host details are distributed to the clients.If there is a disconnection, a check is performed automatically to see if the GUI Server and CMS have failed over to the secondary (or primary if it is a fallback). | N/A | 
| Reconnecting Control-M Web clients: 
 | 
 | Type the Web client URL of the secondary host. | 
| Control-M/EM failover fails to complete. | 
 | Run the following command on the primary host: em emcha -restore primary | 
| Parent Topic |