Step 1 Ensure standby redo logs are configured on
the primary and target standby databases.
Standby redo logs must be configured on the
primary and standby databases. You must stop log apply services prior to
configuring standby redo logs.
Step 2 Ensure the LogXptMode Property is set to
SYNC.
The LogXptMode configurable database property must
be set to SYNC on the primary and target standby databases.
To set the redo transport service that corresponds
to the protection mode you plan to set, use the EDIT DATABASE (property)
command on the primary and target standby databases.
For example, if the protection mode to be set is
MAXAVAILABILITY, you must set the LogXptMode property to SYNC on the primary
database and on the target standby database, as shown in the following
examples:
DGMGRL> EDIT DATABASE
'North_Sales' SET PROPERTY 'LogXptMode'='SYNC';
Property "LogXptMode" updated
DGMGRL> EDIT DATABASE
'DR_Sales' SET PROPERTY 'LogXptMode'='SYNC';
Property "LogXptMode" updated
The broker does not allow these commands to
succeed unless the databases are configured with standby redo log files.
Step 3 Set the FastStartFailoverTarget
configuration property.
If you have two or more standby databases, set up
the FastStartFailoverTarget configuration property on the primary database to
indicate the desired target standby database. For example:
DGMGRL> EDIT DATABASE
'North_Sales' SET PROPERTY FastStartFailoverTarget='DR_Sales';
Property "FastStartFailoverTarget"
updated
Step 4 Upgrade the protection mode to
MAXAVAILABILITY, if necessary.
If it is necessary to upgrade the protection mode,
use the following DGMGRL EDIT CONFIGURATION command. For example:
DGMGRL> EDIT
CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;
Step 5 Enable Flashback Database on the primary and
target standby databases, if necessary.
If it is not already enabled on the primary and
standby databases, enable Flashback Database by issuing the following
statements on each database:
ALTER SYSTEM SET
UNDO_RETENTION=3600 SCOPE=SPFILE;
ALTER SYSTEM SET
UNDO_MANAGEMENT='AUTO' SCOPE=SPFILE;
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
SHOW PARAMETER UNDO;
ALTER SYSTEM SET
DB_FLASHBACK_RETENTION_TARGET=4320 SCOPE=BOTH;
ALTER DATABASE
ARCHIVELOG;
ALTER DATABASE
FLASHBACK ON;
ALTER DATABASE OPEN;
Ensure the
UNDO_RETENTION and DB_FLASHBACK_RETENTION_TARGET initialization parameters are
set to sufficiently large values so that reinstatement is still possible after
a prolonged outage.
Step 6 Start the observer.
Start the observer by logging into the observer
computer and running DGMGRL. Connect to the configuration as SYS and then issue
the START OBSERVER command. Note that the command does not return; that is you
will not get DGMGRL prompt after issuing the command.
DGMGRL> CONNECT
sys@North_Sales.foo.com;
Password: password
Connected.
DGMGRL> START OBSERVER;
Observer started
When starting the observer interactively, Oracle
recommends that connection credentials be supplied as a command parameter to the
DGMGRL CONNECT command, as shown in the example, rather than as a command line
parameter to the DGMGRL command. This practice prevents other users on the
system from using a utility (for example, the UNIX ps utility) to display the
connection credentials.
When starting the observer from a script, Oracle
recommends that you use a method that supports 'connect /', so that database
connection credentials do not have to be embedded within the script. If you
choose to use a client-side Oracle Wallet as a secure external password store
(see Oracle Database Advanced Security Administrator's Guide), be sure to add
credentials for both the primary and fast-start failover target standby
databases. The database connect string that you specify when adding the credentials
for each database must match the ObserverConnectIdentifer or
DGConnectIdentifier configurable database property.
Step 7 Enable fast start failover.
You can enable fast-start failover while connected
to any database system in the broker configuration. For example:
DGMGRL> ENABLE
FAST_START FAILOVER;
Enabled.
Step 8 Verify the fast-start failover
configuration.
Use the SHOW FAST_START FAILOVER command to
display the fast-start failover settings:
DGMGRL> SHOW FAST_START
FAILOVER;
Fast-Start Failover:
ENABLED
Threshold: 30 seconds
Target: DR_Sales
Observer: observer.foo.com
Lag Limit: 30 seconds (not in use)
Shutdown Primary: TRUE
Auto-reinstate: TRUE
Configurable Failover Conditions
Health Conditions:
Corrupted Controlfile YES
Corrupted Dictionary YES
Inaccessible Logfile NO
Stuck Archiver NO
Datafile Offline YES
Oracle Error Conditions:
(none)
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