Before we start, remember that DG broker does not have the ability to create standby and is used for managing the dataguard configuration. Before proceeding with step-by-step instructions on how to set up DG broker, I would recommend you to get comfortable with the concepts first.
Physical Standby Concepts
DataGuard Broker Concepts
The following configuration was tested on RHEL4U2 64-bit with Oracle 10.1.0.5 database.
Pri db_unique_name = 'TESTPRI'
DG db_unique_name = 'TESTDG'
Configuration(any name) = 'DG_TEST'
sys password = 'sys'
Pri conn stg = 'TESTPRI'
1. Set up init parameters on primary to enable broker
Note: For RAC, ensure dg_broker_config_files are on shared storage and accessible to all the instances.
Note: Broker config files are named as dr1<<db_unique_name>>.dat and dr2<<db_unique_name>>.dat
SQL> alter system set dg_broker_start=false sid='*';
System altered.
SQL> alter system set dg_broker_config_file1='/n01/dg_broker_config_files/dr1TESTPRI.dat' sid='*';
System altered.
SQL> alter system set dg_broker_config_file2='/n01/dg_broker_config_files/dr2TESTPRI.dat' sid='*';
System altered.
SQL> alter system set dg_broker_start=true sid='*';
System altered.
2. Verify if DMON process has started on all the instances of primary. Example:
$ ps -ef|grep dmon|grep -v grep
oracle 16190 1 0 08:53 ? 00:00:00 ora_dmon_TESTPRIR1
$ ps -ef|grep dmon|grep -v grep
oracle 29723 1 0 08:53 ? 00:00:00 ora_dmon_TESTPRIR2
3. Set up init parameters on standby
SQL> alter system set dg_broker_start=false sid='*';
System altered.
SQL> alter system set dg_broker_config_file1='/export/crawlspace/dg_broker_config_files/dr1TESTDG.dat' sid='*';
System altered.
SQL> alter system set dg_broker_config_file2='/export/crawlspace/dg_broker_config_files/dr2TESTDG.dat' sid='*';
System altered.
SQL> alter system set dg_broker_start=true sid='*';
System altered.
4. GLOBAL_DBNAME should be set to <<db_unique_name>>_DGMGRL.<<db_domain>> in listener.ora on all instances of both primary and standby.
This is important otherwise you'll have TNS-12154 error during switchover operation.
Example:
SID_LIST_LISTENER_TESTPRI =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /apps/oracle/product/10g/db)
(PROGRAM = extproc)
)
(SID_DESC =
(SID_NAME = TESTPRIR1)
(GLOBAL_DBNAME = TESTPRI_DGMGRL)
(ORACLE_HOME = /apps/oracle/product/10g/db)
)
)
5. DGMGRL Configuration
5.1Connect
DGMGRL> CONNECT sys/sys
Connected.
5.2Create Configuration
DGMGRL> CREATE CONFIGURATION 'DG_TEST' AS PRIMARY DATABASE IS 'TESTPRI' CONNECT IDENTIFIER IS TESTPRI;
Configuration "DG_TEST" created with primary database "TESTPRI".
5.3Verify configuration
DGMGRL> SHOW CONFIGURATION;
Configuration
Name: DG_TEST
Enabled: NO
Protection Mode: MaxPerformance
Databases:
TESTPRI - Primary database
Current status for "DG_TEST":
DISABLED
5.4Verify database; if RAC verify if all instances are validated
DGMGRL> show database 'TESTPRI';
Database
Name: TESTPRI
Role: PRIMARY
Enabled: NO
Intended State: ONLINE
Instance(s):
TESTPRIR1
TESTPRIR2
Current status for "TESTPRI":
DISABLED
5.5Add standby database to the configuration
DGMGRL> ADD DATABASE 'TESTDG' AS CONNECT IDENTIFIER IS TESTDG MAINTAINED AS PHYSICAL;
Database "TESTDG" added.
5.6Enable the broker
DGMGRL> ENABLE CONFIGURATION;
Enabled.
5.7Verfying again
DGMGRL> SHOW CONFIGURATION;
Configuration
Name: DG_TEST
Enabled: YES
Protection Mode: MaxPerformance
Databases:
TESTPRI - Primary database
TESTDG - Physical standby database
Current status for "DG_TEST":
SUCCESS
6. Troubleshooting
Let us see some sample issues and their fix
Issue
DGMGRL> CONNECT sys/sys
ORA-16525: the Data Guard broker is not yet available
Fix
Set dg_broker_start=true
Issue
After enabling the configuration, on issuing SHOW CONFIGURATION, this error comes
Warning: ORA-16608: one or more sites have warnings
Fix
To know details of the error, you may check log which will be generated at bdump with naming as drc{DB_NAME}.log or there are various monitorable properties that can be used to query the database status and assist in further troubleshooting.
Few Monitorable properties to troubleshoot
DGMGRL> SHOW DATABASE 'TESTPRI' 'StatusReport';
DGMGRL> SHOW DATABASE 'TESTPRI' 'LogXptStatus';
DGMGRL> SHOW DATABASE 'TESTPRI' 'InconsistentProperties';
DGMGRL> SHOW DATABASE 'TESTPRI' 'InconsistentLogXptProps';
DGMGRL> SHOW DATABASE 'TESTDG' 'StatusReport';
DGMGRL> SHOW DATABASE 'TESTDG' 'LogXptStatus';
DGMGRL> SHOW DATABASE 'TESTDG' 'InconsistentProperties';
DGMGRL> SHOW DATABASE 'TESTDG' 'InconsistentLogXptProps';
Issue
DGMGRL> SHOW DATABASE 'TESTPRI' 'StatusReport';
STATUS REPORT
INSTANCE_NAME SEVERITY ERROR_TEXT
TESTPRIR2 WARNING ORA-16714: The value of property ArchiveLagTarget is inconsistent with the database setting.
TESTPRIR2 WARNING ORA-16714: The value of property LogArchiveMaxProcesses is inconsistent with the database setting.
Issue
DGMGRL> SHOW DATABASE 'TESTPRI' 'InconsistentProperties';
INCONSISTENT PROPERTIES
INSTANCE_NAME PROPERTY_NAME MEMORY_VALUE SPFILE_VALUE BROKER_VALUE
TESTPRIR2 ArchiveLagTarget 0 0
TESTPRIR2 LogArchiveMaxProcesses 4 2 4
Example
DGMGRL> SHOW DATABASE 'TESTPRI' 'LogArchiveMaxProcesses';
LogArchiveMaxProcesses = '4'
Fix
DGMGRL> EDIT DATABASE 'TESTPRI' SET PROPERTY 'LogArchiveMaxProcesses'=2;
or
SQL> alter system set log_archive_max_processes=4 scope=spfile sid='*';
System altered.
DGMGRL> SHOW DATABASE 'TESTPRI' 'LogArchiveMaxProcesses';
LogArchiveMaxProcesses = '4'
More commands
DGMGRL> SHOW DATABASE VERBOSE 'dbname';
This will show all property values in detail
DGMGRL> HELP;
List of all broker commands with usage help
Equivalent Broker Commands to 'ALTER SYSTEM'
SQL> alter database recover managed standby database cancel;
DGMGRL> edit database 'stby_dbname' set state='LOG-APPLY-OFF';
SQL> alter database recover managed standby database disconnect;
DGMGRL> edit database 'stby_dbname' set state='ONLINE';
SQL> alter system set log_archive_max_processes=4;
DGMGRL> edit database 'dbname' set property 'LogArchiveMaxProcesses'=4;
SQL> alter system set log_archive_dest_state_2='enable' scope=both;
DGMGRL> edit database 'stby_dbname' set property 'LogShipping'='ON';
SQL> alter system set log_archive_dest_state_2='defer' scope=both;
DGMGRL> edit database 'stby_dbname' set property 'LogShipping'='OFF';
DGMGRL> edit database 'pri_dbname' set state='LOG-TRANSPORT-OFF';
This will defer all standby databases
That's it my friends. You are all set to use broker now for managing your dataguard configuration. In my next blog, I'll talk about switchover using DG broker