1. Concepts
  2. Scenarios for Using DGMGRL with a DG PDB Configuration (23ai)
  3. Scenario 6: Configure Data Guard Protection for the Source PDB

Scenario 6: Configure Data Guard Protection for the Source PDB

Configure Data Guard PDB-level protection for the source PDB bos_sales by configuring target PDB nyc_sales in the newyork container database. This is implemented in four tasks:
  1. Execute the ADD PLUGGABLE DATABASE command to create the target PDB in the target container database.
  2. Instantiate the target PDB by copying the all files associated with the source PDB to the target PDB location.
  3. Create PDB-level standby redo logfiles (SRLs) to receive foreign source redo.
  4. Initiate redo transport from the source PDB to the target PDB.
Task 1: execute the ADD PLUGGABLE DATABASE command. 
DGMGRL> ADD PLUGGABLE DATABASE 'nyc_sales' AT newyork SOURCE is 'bos_sales' AT boston PDBFileNameConvert is 
"'/BOSTON/bos_sales/','/NEWYORK/nyc_sales/'"; 
Pluggable Database "NYC_SALES" added
Task 2: instantiate the target PDB.
On the target system, create a directory to contain the target PDB files. The name and location for this directory and for the copied files must follow the rules specified in the the PDBFileNameConvert clause of the ADD PLUGGABLE DATABASE command. Replace <myowner> and <nychost> with values approprirate for your environment. 
$ cd $ORACLE_BASE/oradata/NEWYORK 
$ mkdir nyc_sales
Copy the source PDB files into this directory. The example uses the Linux operating system secure copy command scp to perform this task.
On the source host, connect to the source CDB boston as SYSDBA and issue the following SQL commands: 
SQL> ALTER SESSION SET CONTAINER=bos_sales; 
Session altered. 
SQL> ALTER DATABASE BEGIN BACKUP; 
Database altered. 
SQL> host scp -r $ORACLE_BASE/oradata/BOSTON/bos_sales/* 
<myowner>@<nychost>:$ORACLE_BASE/oradata/NEWYORK/nyc_sales 
sysaux01.dbf  100%   930MB   22.4MB/s   00:41 
system01.dbf  100%   310MB   27.7MB/s   00:11 
temp01.dbf    100%   20MB    92.0MB/s   00:00 
undotbs01.dbf 100%   100MB   54.9MB/s   00:01 
users01.dbf   100%   5128KB  55.0MB/s   00:00 
SQL> ALTER DATABASE END BACKUP; Database altered.
Task 3: create PDB-level standby redo logfiles.

This step is only performed the first time a target PDB is configured within a container database.

For traditional Data Guard deployments, standby redo logfiles (SRLs) typically are added to the primary database at the CDB level before creating any standby databases so RMAN will automatically propagate these files to all standby databases subsequently created from the primary database.

For DGPDB deployments, by contrast, SRLs are added at the PDB level after the initial DGPDB configuration and one or more target PDBs have been created. PDB-level SRLs can be added only to PDBs in the target role. If a CDB has multiple PDBs in the target role, all of these target PDBs share the same set of PDB-level SRLs to receive redo from their corresponding source PDBs. In addition, if a CDB has no PDBs in the target role, a role change from source role to target role for one PDB must be performed before any PDB-level SRLs can be created for that CDB. For the example configuration, PDB-level SRLs will be added to the current source PDB bos_sales in Scenario 7: Switchover from Source PDB to Target PDB.

Connect to the target CDB newyork as SYSDBA and issue the following SQL commands to add PDB-level SRLs. Note that the size specified for the PDB level SRLs must be the same size as the source container database online redo log files (ORLs) and that typically the number of PDB-level SRLs is one more than the number of source ORLs to help ensure there is always a free target PDB-level SRL available to receive redo from the source CDB. 
SQL> ALTER SESSION SET CONTAINER=nyc_sales; 
Session altered. 
SQL> ALTER DATABASE ADD STANDBY LOGFILE thread 1 
  2 group 4 ('$ORACLE_BASE/fast_recovery_area/NEWYORK/onlinelog/standby_redo04.log') size 200M, 
  3 group 5 ('$ORACLE_BASE/fast_recovery_area/NEWYORK/onlinelog/standby_redo05.log') size 200M, 
  4 group 6 ('$ORACLE_BASE/fast_recovery_area/NEWYORK/onlinelog/standby_redo06.log') size 200M, 
  5 group 7 ('$ORACLE_BASE/fast_recovery_area/NEWYORK/onlinelog/standby_redo07.log') size 200M; 
Database altered.
Use the VALIDATE PLUGGABLE DATABASE command to confirm successful creation of the PDB level standby redo logfiles: 
DGMGRL> VALIDATE PLUGGABLE DATABASE nyc_sales AT newyork;   
  Ready for Switchover:    NO 
  Data Guard Role:         Physical Standby 
  Apply State:             Not Running 
  Standby Redo Log Files:  4   
  Source:                  BOS_SALES (con_id 3) at boston
Task 4: initiate redo transport from the source PDB to the target PDB.
Note that redo apply is not running. Use DGMGRL to start redo apply on the target PDB. 
DGMGRL> EDIT PLUGGABLE DATABASE nyc_sales AT newyork SET STATE='APPLY-ON'; 
Succeeded. 
DGMGRL> SHOW CONFIGURATION; 
Configuration - Boston 
  Protection Mode: MaxPerformance 
  Members: 
  boston - Primary database 
  newyork - Primary database in NewYork configuration 
Data Guard for PDB: Enabled in SOURCE role 
Configuration Status: 
SUCCESS (status updated 3 seconds ago) 

DGMGRL> SHOW PLUGGABLE DATABASE bos_sales AT boston; 
Pluggable database - BOS_SALES at boston 
  Data Guard Role:   Primary 
  Con_ID:            3 
  Active Target:     con_id 3 at newyork 
Pluggable Database Status: 
SUCCESS 

DGMGRL> SHOW PLUGGABLE DATABASE nyc_sales AT newyork; 
Pluggable database - NYC_SALES at newyork 
  Data Guard Role:    Physical Standby 
  Con_ID:              3 
  Source:              con_id 3 at boston 
  Transport Lag:       13 minutes 11 seconds (computed 59 seconds ago) 
  Apply Lag:           (unknown) 
  Intended State:      APPLY-ON 
  Apply State:         Running 
  Apply Instance:      newyork 
  Average Apply Rate:  (unknown) 
  Real Time Query:     OFF 
Pluggable Database Status: 
SUCCESS
Note that although redo apply is running on the target PDB, there is a transport lag. Connect to the source CDB boston as SYSDBA and archive the current log a few times to initiate redo transport to the newly configured standby redo logfiles: 
SQL> ALTER SYSTEM ARCHIVE LOG CURRENT; 
System altered. 

SQL> ALTER SYSTEM ARCHIVE LOG CURRENT; 
System altered.
When the state of the target PDB is checked again, the target PDB is protecting the source PDB with no transport or apply lag. 
DGMGRL> SHOW PLUGGABLE DATABASE nyc_sales AT newyork; 
Pluggable database - NYC_SALES at newyork 
  Data Guard Role:        Physical Standby 
  Con_ID:                 3 
  Source:                 con_id 3 at boston  
  Transport Lag:          0 seconds (computed 0 second ago) 
  Apply Lag:              0 seconds (computed 0 second ago) 
  Intended State:         APPLY-ON 
  Apply State:            Running 
  Apply Instance:         newyork 
  Average Apply Rate:     178 KByte/s 
  Real Time Query:        OFF 
Pluggable Database Status: 
SUCCESS
Continue to use this DGMGRL session in the next scenario.