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redo generation on the primary database will be stalled. FastStartFailoverLagLimit configuration property. If the credentials cannot be obtained, then the attempted command fails (but only for the broker configuration whose credentials have not been obtained). See Manual Failover for information about manual failover. For reliable startup, the initial connection should always be made to the primary. The failover time is dependent upon whether the target standby database (physical or logical standby database) has applied all of the redo data it has received from the primary database. Fast-start failover enables the Data Guard broker to rapidly and automatically failover to a previously chosen standby database without requiring manual intervention. Learn how your comment data is processed. SQL> Select Database_role from v$Database; Some properties have changed between those releases. The following sections describe these topics: Prerequisites for Enabling Fast-Start Failover, Viewing Fast-Start Failover Configuration Statistics and Status, Performance Considerations for Fast-Start Failover, Reinstating the Former Primary Database in the Broker Configuration, Shutting Down Databases In a Fast-Start Failover Environment. If Flashback Database was enabled on the primary database.If not, the whole setup process must be followed, but this time using the original primary server as the standby. When the process is complete, the database will be enabled as a standby database to the new primary database, and Cloud Control displays the Oracle Data Guard Overview page. 1. For this build, we will use a single physical standby database. disable fast-start failover with the FORCE option on the This is to ensure that the service definition gets propagated to the physical standby database via the redo stream and thus allows for the service to be started on the physical standby database. If the observer is stopped abnormally (for example, by typing CTRL/C), restart it and reference the existing fsfo.dat file with the FILE IS qualifier. For Maximum Availability environments, change this to synchronous. If the WAIT option is included in the Using the db_unique_name of each database as the Oracle Net alias is simple and intuitive. A failover may or may not result in data loss depending on the protection mode in effect at the time of the failover. VALIDATE Read-Only Standby and Active Data Guard The terminal session will appear to hang at this point. A far-sync instance cannot be used in maximum protection mode. Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. configuration named ConfigurationSimpleName. Step:1 Check the database role and open_mode directory. database is in the primary role. In this case, the primary database stalls and prevents any further transactions from Use the EMCLI verb dg_configure_observers. Prerequisites for Enabling Fast-Start Failover provides complete information about all of the fast-start failover and reinstatement requirements. The real test of the configuration is a successful role transition in both directions with both switchover and FSFO failover. It wouldn't be much of a test if we didn't verify that our durability constraints were being met, so let's make a change on the primary and see if it survives the failover. callout configuration file. Flashing back a database occurs in two stages: For FSFO environments, set db_flashback_retention_target = 60 or higher to provide sufficient Flashback Database history for automatic standby reinstatement. Client-side broker After the database has been re-created, enable broker management of the re-created standby database by using the DGMGRL ENABLE DATABASE command. multiple, inexpensive servers is the basis for the failover and other fault-tolerance features that RAC provides. fast-start failover has not occurred to the target standby database. Therefore, the primary database can continue processing transactions, even if the target standby database fails. SUSPENDED is cleared when connectivity with the primary database is restored. Neither the primary database nor the logical standby database needs to be restarted after the switchover completes. OBSERVE-ONLY: Fast-start failover is enabled in observe-only mode. The standby can be physical or logical and there can be multiple standbys, but only one of the standbys can be the failover target at any given time. Once fast-start failover is enabled, the broker will ensure that fast-start failover Step-by-step instructions for manual reinstatement are described in Reenabling Disabled Databases After a Role Change. This article - the seventh in this ongoing . You cannot create the standby DB system in a different AD from the primary DB system. In Maximum Availability mode, FSFO guarantees that no transaction that has received a commit acknowledgment will be lost during a failover. A failover may or may not result in data loss depending on the protection mode in effect at the time of the failover. Many customers use Oracle Database deployed on Amazon Elastic Compute Cloud (Amazon EC2) to run their Oracle E-Business Suite applications. If you will be using RMAN to create the standby database, it also needs a static service to restart the database being created. Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). SHOW OBSERVER command to confirm that the switch took place. The value specified for either of these properties should allow the master observer to connect to any instance of an Oracle RAC database. In this case, Flashback Database cannot be used to reinstate databases. A switchover is a role reversal between the primary database and one of its standby databases. (as it might in maximum availability and maximum performance modes). You can perform a manual failover even if fast-start failover is enabled. If the configuration contains both physical and logical standby databases, consider choosing a physical standby database (that has the least amount of unapplied redo) to be the target standby database. After a role change, the naming service can be updated with the new primary's address. The steps in this section describe the tasks involved to perform a manual failover. Oracle Data Guard helps you change the role of databases between primary and standby using either a switchover or failover operation. FastStartFailoverAutoReinstate is set to FALSE, Another failover or switchover occurred after the fast-start failover completed but before the former primary database restarted, The master observer cannot connect to the former primary database, The former primary database cannot connect to the new primary database, The former primary database and the new primary database are not configured in the same fast-start failover environment, The former primary database was disabled because of a manual failover when fast-start failover was disabled. To optimize the log apply rate: Do not configure the DelayMins database property to delay applying archived redo log files to the standby database (see Managing Log Apply Services for more information). Whether or not you need the FORCE option depends mostly on if the primary and target standby database have network connectivity: If the primary and target standby database have network connectivity, and the database to which you are connected has network connectivity with the primary database, the FORCE option has no effect. The ObserverReconnect configuration property specifies how often the observer establishes a new connection to the primary database. Moorestown, New Jersey, United States. computer, it automatically starts the observer when you enable An immediate failover is the fastest type of failover. The DB_ROLE_CHANGE event will fire whenever a database is opened for the first time after a role transition. Flashing back a database is much faster and more seamless (one simple DDL statement) than traditional point-in-time or SCN-based recovery. Once an observer is started, no further user interaction is required. You can use this information to identify ahead of time any redo transport configurations that would be incorrect after a role change, including any standbys that will not receive redo because the RedoRoutes property was not configured correctly. The following table summarizes which standby types are supported in which protection modes when fast-start failover is enabled. See theFlashback Database section above for information on storage requirements. You must provide a connect identifier, through which one or more databases in a specific broker configuration can be reached. They cannot be reinstated. Note that if the V$DATABASE.FS_FAILOVER_STATUS column has a value of DISABLED, then any values returned for the remaining columns related to fast-start failover (V$DATABASE.FS_FAILOVER_*) become irrelevant. PRIM>connect /@PRIM as sysdba For example, perform full level 0 backups weekly and incremental level 1 backups daily. Theoretically, this method can be used when a data guard failover occurred between the primary and standby database, but not a switchover. This table describes the optional database properties that you can set. MASTEROBSERHOST TO command. Use Broker's "show configuration" command to determine FSFO status and the "show database statusreport" command to drill down for details if Broker reports a problem. The physical and snapshot standby databases will have to be re-created from a copy of the new primary database. FSFO can also be used with logical standbys and an FSFO-enabled configuration may have multiple standbys with a mix of physical and logical, but only one standby can be the failover target at any given time. In a complete failover, it is also possible to failover to a standby database (terminal standby) that gets redo from another standby database (cascader). The following sections provide more information about the fast-start failover environment: When Fast-Start Failover Is Enabled and the Observer Is Running, Restrictions When Fast-Start Failover is Enabled, Shutting Down the Primary Database When Fast-Start Failover Is Enabled, Performing Manual Role Changes When Fast-Start Failover Is Enabled. maximum availability and maximum performance modes, to avoid a If a failure occurs once a reinstatement operation (automatic or manual) is underway, the broker logs the appropriate information in the broker configuration files and broker log files. Credentials Required for Access to Broker Configurations. If the Cloud Control agent is installed on the observer Errors occurring for any other configuration members will not impede the switchover. The broker interacts with Oracle Clusterware or Oracle Restart to ensure that the appropriate database services are active and that the appropriate FAN events are published after a role change. Twitter:https://twitter.com/hariprasathdba, In The following steps all require the database to be in a mounted (not open) state. FastStartFailoverLagLimit The default name for If the target standby database is ready for failover, then the master observer immediately directs the target standby database to fail over to the primary database role. Such preparation includes: Ensuring that standby redo log files are configured on the primary database. Then, These commands can be issued from the DGMGRL command line, but it is not necessary to log on prior to using them. required permissions, the admin folder is created Data Guard Broker - Controls the creation and monitoring of Data Guard. After the restart, Redo Apply begins applying redo data from the new primary Data Guard broker publishes this service on each instance as it comes up and broker management of the instance is initialized: To patch an environment where the Observer is running and fast-start failover is enabled, follow these steps prior to applying the patch. The following sections provide information about managing observers: How the Observer Maintains Fast-Start Failover Configuration Information, Patching an Environment When the Observer Is Running and Fast-start Failover Is Enabled. All database connections associated with the observer, including the initial connection, must use dedicated server connections. Immediate Failovers in Configurations Using Far Sync Instances. Note that the database will not open at this point. The configuration status returns the SUCCESS status after the observer reestablishes its connection to the primary database, which then notifies the target standby database. learning with R and Python are also covered in this step-by-step tutorial. db_domain . groups used by multiple configuration commands. The same process should work for RAC environment as my colleague has . This is Startup can fail with "ORA-16647: could not start more than one observer" even when no observer is actually running if the previous observer process terminated without deregistering itself and the new observer isn't using the previous fsfo.dat file. You can, however, perform a manual failover to a snapshot standby. If all the databases do not have the same values, SRVCTL attempts to override the values, which will fail on the physical standby database because it is open read-only. Remote login is required, along with a password file, to allow the databases in a Data Guard configuration to connect to each other. When fast-start failover is enabled, the broker determines if a failover is necessary and initiates the failover to the current target standby database automatically, with no need for manual intervention. As mentioned above, Maximum Availability mode is mandatory for Oracle Database 10g and optional for Oracle Database 11g. 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. One is the master The minimum detection time is 6 seconds, which is the default SET ObserverConfigFile used to specify a customized observer configuration file. You want to conduct a manual failover to any standby database in the configuration (for example, because a failure occurred on the primary database at a time when the primary and target standby database were not ready to failover). Monitoring flashback database history and reacting when it drops below 30 minutes will save you time and improve availability. On the Oracle Data Guard Overview page, click Database must be reinstated. This list contains some recommendations to obtain better performance when using fast-start failover. In addition, some standby databases may be disabled by the broker during the failover if the broker detects that they have applied redo beyond where the new primary database had applied. To stop the observer, see Stopping the Observer. See Oracle Enterprise Manager Command Line Interface. As described in theFlashback Database section, Flashback Database takes place in two stages: a restore stage and a media recovery stage. Some of the statistics that can be monitored are as follows: LAST_FAILOVER_TIME that shows the timestamp of last fast-start failover, LAST_FAILOVER_REASON that shows the reason for the last fast-start failover. If you performed a failover or switchover that requires you to re-create the failed primary database or standby databases that were disabled during the role transition, then follow the procedures in the Oracle Data Guard Concepts and Administration chapter, "Creating a Physical Standby Database" and also the Oracle Data Guard Concepts and Administration chapter, "Creating a Logical Standby Database.". See Enabling Fast-Start Failover for more information. Broker will set the primary to use asynchronous log transport by default. In the event of a You can start, stop, and show observers for a group of configurations. We'll leave the other properties at their default values for the walkthrough, but you should become familiar with all of the Broker config and database properties. In the following example, a service named sales is configured to be active in the PHYSICAL_STANDBY role on the primary database NORTH. The observer automatically starts the reinstatement process. See Manual Failover for complete information about manual failovers. Thus, the command-line prompt on the observer computer does not issue commands and interact with the broker configuration. When you configure data guard using OCI console, the default mode is set to maxprotection. Look for the desired data in the RAM. For example: In the following example, assume the network between the primary database and the observer has failed. Note the primary and target standby must have connectivity for this command to complete successfully. Use Cloud Control or DGMGRL to perform either a complete (recommended) or an immediate failover. Subsequent changes to the same block during the same snapshot are not recorded. 4. Logical standby databases that are disabled during failover can be reinstated. RMAN will copy the spfile from the primary, so this init.ora file is only needed during the first phase of the duplication. Presetting database properties related to redo transport services, such as LogXptMode, NetTimeout, StandbyArchiveLocation, StandbyAlternateLocation, and RedoRoutes. In an environment where there are multiple observers configured, stopping the master observer is not allowed unless it is the last running observer. observer computer is returned to you so that you can continue to Choose a value high enough to avoid false disconnects from intermittent network trouble. on particular instances based on the service configuration. Whether or not standby databases that were not the target of failover (bystander standby databases) are disabled depends upon how much redo data they have applied relative to the failover target and the standby type of the failover target: If the failover target is a physical or snapshot standby database, the original primary database must be reinstated or re-created in order to be a standby database for the new primary database. But it will also continue trying to reconnect to the primary database indefinitely. *PATCH V3 0/6] ASoC: codecs: Add Awinic AW883XX audio amplifier driver [not found] <000701d8e7521f78bc05e6a340awinic.com> @ 2022-11-11 11:26 ` wangweidong.a 2022-11 . FastStartFailoverThreshold for reference information about the FastStartFailoverThreshold property. Oracle Data Guard Broker is a utility that can help you manage your Oracle Data Guard. Broker checks to see if Flashback Database is enabled on the primary and failover targets when FSFO is enabled. Stores files related to the observer and callout configuration. Verify the configuration from both hosts. If you are performing an immediate failover, then the database role is changed to primary without applying any accumulated redo data. In order to apply redo data to the standby database as soon as it is received, use Real-time apply. ORACLE instance shut down. If it detects that Flashback Database was disabled, either manually, or automatically because Flashback Database discovered a problem, Broker signals "ORA-16827: Flashback Database is disabled".