Examine the Fast-start configuration:
DGMGRL> show fast_start failover;
Fast-Start Failover: ENABLED
Threshold : 30 seconds
Target: sheep
Observer : 017.example.com
Lag Limit: 30 seconds (not in use)
Shutdown Primary: TRUE
Auto-reinstate: TRUE
Observer Reconnect: (none)
Observer Override: FALSE
Configurable Failover Conditions
Health Conditions:
Corrupted Controlfile YES
Corrupted Dictionary YES
Inaccessible Logfile NO
Stuck Archiver YES
Datafile Offline YES
Oracle Error Conditions:
(none)
Which three are true?
A.
The observer will initiate a failover when the primary database is unable to produce local archived redo log files.
B.
An automatic failover will be initiated even if the target standby database lags behind the primary.
C.
The observer is running.
D.
A failover may occur if the observer has lost connectivity to the primary database, even if the Fast-Start Failover target standby database has a good connection
to the primary database.
E.
The configuration operates in Maximum Availability mode.
F.
The configuration operates in Maximum Performance mode.
Explanation:
A: Stuck Archiver: YES
Archiver is unable to archive a redo log because the device is full or unavailable.
C: Observer : 017.example.com
E: The FastStartFailoverLagLimit configuration property is only used by the broker when enabling fast-start failover for configurations operating in maximum
performance mode.docs.oracle.com/cd/E11882_01/server.112/e40771/sofo.htm
Maximum performance mode provides an automatic failover environment guaranteed to lose no more than the amount of data (in seconds) specified by the FastStartFailoverLagLimit configuration property. This property indicates the maximum amount of data loss that is permissible in order for an automatic failover to occur. It is only used when fast-start failover is enabled and the configuration is operating in maximum performance mode.
If both the observer and designated standby database lose connectivity with the primary database for longer than the number of seconds specified by the FastStartFailoverThreshold configuration property, the observer will initiate a fast-start failover to the standby database.
In addition, the primary database will shut down if it perceives a loss of connectivity for a period longer than FastStartFailoverThreshold seconds, if the FastStartFailoverPmyShutdown configuration property is set to TRUE. After the failover completes, the former primary database is automatically reinstated as a standby database when a connection to it is reestablished, if the
FastStartFailoverAutoReinstate configuration property is set to TRUE.
Hi PeraDeltic
And? do you agree or no?
Regards
Hi
D is false http://docs.oracle.com/database/121/DGBKR/sofo.htm#BCGFFFH
If the primary and target standby databases stay connected but the connection to the observer is lost, then the broker reports that the configuration is not observed. The configuration and database status report that the observer is not running and return one of the following status messages:
ORA-16658: unobserved fast-start failover configuration
ORA-16820: fast-start failover observer is no longer observing this database
While the configuration is in the unobserved state, fast-start failover cannot happen. Therefore, the primary database can continue processing transactions, even if the target standby database fails. The configuration status returns the SUCCESS status after the observer reestablishes its connection to the primary database, which then notifies the target standby database.
Thanks
I think ACE is correct
A – Correct! (Stuck Archiver YES) – Stuck Archiver: Archiver is unable to archive a redo log because the device is full or unavailable.
B – Correct, until the lags of 30 seconds; (Lag Limit: 30 seconds (not in use))
C – Correct, the observer was in (Observer : 017.example.com)
D – This is wrong, the failover will be occur only if the observes was not able to connect with the primary and the standby is unable to connect with the primary
E – Correct!
F – Correct!
Prerequisites for Enabling Fast-Start Failover
The following prerequisites must be met before the broker allows you to enable fast-start failover:
Ensure the broker configuration is operating in either maximum availability mode or maximum performance mode.
See Setting the Protection Mode for Your Configuration for information about configuring the protection mode, standby redo logs, and the redo transport mode.
The selected standby database that will be the fast-start failover target must receive redo directly from the primary database or from a far sync instance.
Ensure that the standby database you choose to be the target of fast-start failover has its LogXptMode property set to either SYNC or FASTSYNC if you wish to enable fast-start failover in maximum availability mode, or to ASYNC if you wish to enable fast-start failover in maximum performance mode. The current primary database must have its LogXptMode property set accordingly and must have standby redo logs configured. Alternatively, use the RedoRoutes property to configure the redo transport mode for the target standby and the database currently in the primary role.
To use a far sync instance with fast-start failover, the far sync instance transport mode must be set to either SYNC or FASTSYNC and the target standby database transport mode must be set to ASYNC.
Enable Flashback Database and set up a fast recovery area on both the primary database and the target standby database.
See Oracle Database Backup and Recovery User’s Guide.
Install the DGMGRL command-line interface on the observer computer as described in Oracle Data Guard Installation.
Configure the TNSNAMES.ORA file on the observer system so that the observer is able to connect to the primary database and to the pre-selected target standby database.
If you are not using Oracle Clusterware or Oracle Restart, then you must create static service names so that the observer can automatically restart a database as part of reinstatement. See Prerequisites for more information.
https://docs.oracle.com/database/121/DGBKR/sofo.htm#DGBKR391
https://docs.oracle.com/cd/B19306_01/server.102/b14230/sofo.htm#i1027843
A,C,E
A,C and E area correct.
Lag Limit is not used, thats because you are un MAX Availability Mode.