Managing Redo Transport Services for Recovery Appliance

Redo transport services for a Zero Data Loss Recovery Appliance (Recovery Appliance) are managed in the same way as for a standby database.

You can use the broker to manage redo transport services to a Recovery Appliance from any member in the configuration. For example, to add a Recovery Appliance to a broker configuration and then enable it, you would take the following steps:

1. Add the Recovery Appliance to the broker configuration.

   DGMGRL> ADD RECOVERY_APPLIANCE EnterpriseRecoveryAppliance AS CONNECT IDENTIFIER IS
   EnterpriseRecoveryAppliance.example.com;
   Oracle Recovery Appliance "EnterpriseRecoveryAppliance" added
    
   DGMGRL> SHOW RECOVERY_APPLIANCE 'EnterpriseRecoveryAppliance';
    Oracle Recovery Appliance - EnterpriseRecoveryAppliance
      Transport Lag: 0 seconds
     Redo Source: North_Sales
    
   Oracle Recovery Appliance Status:
   DISABLED
   

2. Enable the Recovery Appliance.

   DGMGRL> ENABLE RECOVERY_APPLIANCE 'EnterpriseRecoveryAppliance';
    
   DGMGRL> SHOW RECOVERY_APPLIANCE 'EnterpriseRecoveryAppliance';
    Oracle Recovery Appliance - EnterpriseRecoveryAppliance
      Transport Lag: 0 seconds
     Redo Source: North_Sales
    
   Oracle Recovery Appliance Status:
   SUCCESS
   

3. Set a transport lag threshold.

   Set the TransportLagThreshold database configurable property to generate a health check warning when the transport of redo data to the Recovery Appliance lags behind the generation of redo data on the source database. This step is optional, but if you do not specify a transport lag threshold, then the default value of 30 seconds is used and a warning is generated if a transport lag exceeds 30 seconds.

   The following command sets the TransportLagThreshold property to 15 seconds:

   DGMGRL> EDIT RECOVERY_APPLIANCE 'EnterpriseRecoveryAppliance'
   SET PROPERTY 'TransportLagThreshold'=15;
   Property TransportLagThreshold updated
   

Example 4-9 Setting Up Redo Transport From a Physical Standby To a Recovery Appliance

Consider a configuration that has a primary database (North_Sales) a physical standby database (South_Sales), and a Recovery Appliance (EnterpriseRecoveryAppliance). Instead of the primary having to ship its redo to both the standby and the Recovery Appliance, you can set up the RedoRoutes property so that the primary sends redo only to the physical standby, and the physical standby then forwards that redo to the Recovery Appliance. To accomplish this, the RedoRoutes property must be set as follows:

• On the North_Sales database, the RedoRoutes property must specify that if North_Sales is in the primary role, then it should ship redo to the South_Sales database using synchronous transport mode. This rule prevents the primary from shipping redo data directly to the Recovery Appliance, EnterpriseRecoveryAppliance.

• On the South_Sales database, the RedoRoutes property must specify that if North_Sales is in the primary role, then South_Sales should forward redo it receives from North_Sales on to EnterpriseRecoveryAppliance.

DGMGRL> EDIT DATABASE 'North_Sales' SET PROPERTY 'RedoRoutes' = '(LOCAL : South_Sales SYNC)';
DGMGRL> EDIT DATABASE 'South_Sales' SET PROPERTY 'RedoRoutes' = '(North_Sales : EnterpriseRecoveryAppliance ASYNC)';

Note that the ASYNC redo transport attribute was explicitly specified in the redo route rule for the EnterpriseRecoveryAppliance destination to enable real-time cascading of redo to that destination.

Once a Recovery Appliance has been added to a broker configuration, it can receive redo from either the primary database or a standby database. Example 4-9 shows how to set up a Recovery Appliance to receive redo from a physical standby database.

See Also:

• Managing Redo Transport Services for information about managing redo transport services