Real-time cascading within Oracle Data Guard 12c

The feature real-time cascading within Oracle data guard started with the version of Oracle database 12c, with the broker configuration we can manage physical standby databases configuration easily.

What we have:
Two Oracle databases physical standby updated directly and simultaneously within the production:

What we want to configure:
Configure the Oracle data Guard real Time cascading.

Let’s do it:

Step 1: Check the configuration of 2 physical standby databases:

DGMGRL> show configuration;
Configuration - orcl_ha
Protection Mode: MaxPerformance
   Members:
   orcl  - Primary database
     orcl2 - Physical standby database 
     orcl3 - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
 SUCCESS   (status updated 53 seconds ago)

Note: We have two Physical standby databases orcl2 and orcl3.

A primary database sends its redo to every possible redo transport destination in a broker configuration, and to manage the cascading we are going to use the property REDOROUTES.

Step 2 A: Set up orcl3 as physical standby without real time cascading

DGMGRL> edit database orcl set property redoroutes =(orcl:orcl2);
DGMGRL> edit database orcl2 set property redoroutes =(orcl:orcl3)(orcl3:orcl)(local:orcl,orcl3);
DGMGRL> edit database orcl3 set property redoroutes =(orcl3:orcl2);DGMGRL> show configuration;
Configuration - orcl_ha
Protection Mode: MaxPerformance
   Members:
   orcl  - Primary database
     orcl2 - Physical standby database 
       orcl3 - Physical standby database (receiving archived redo)

Note: Without Real Time cascading: receiving archived redo message.

Step 2 B: Set up orcl3 as physical standby with real time cascading.

DGMGRL> edit database orcl set property redoroutes =(orcl:orcl2);
DGMGRL> edit database orcl2 set property redoroutes = '(orcl:orcl3 ASYNC)(orcl3:orcl ASYNC)(local:orcl,orcl3)';
DGMGRL> edit database orcl3 set property redoroutes =(orcl3:orcl2);
DGMGRL> show configuration;
Configuration - orcl_ha
Protection Mode: MaxPerformance
   Members:
   orcl  - Primary database
     orcl2 - Physical standby database 
       orcl3 - Physical standby database (receiving current redo)

Note: Real Time cascading: receiving current redo message.

Conclusion:

Managing the Real Time cascading feature with broker is become possible starting with 12.