statusreport" command to drill down for details if Broker reports a problem. For Oracle RAC databases, see Oracle Real Application Clusters Administration and Deployment Guide for more information about configuring database services with the SRVCTL utility. It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. Note: this state also occurs on the primary during startup when fast-start failover is possible and neither the target standby database nor the observer are present to confirm it is okay to continue opening the database. Stop the observer using the DGMGRL STOP OBSERVER command. The target standby database has contact with the primary database. Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). This can happen for either of the following reasons: A bystander standby database has applied more redo data than the new primary database itself had applied when it was a standby database. gets enabled and then begins monitoring. All Data Guard environments should enable force logging at the database level in order to guard against nologging tablespaces from being added. The column value for V$DATABASE.FS_FAILOVER_STATUS will be SYNCHRONIZED in a configuration operating in maximum availability mode, and it will be TARGET UNDER LAG LIMIT in a configuration operating in maximum performance mode when ready to fast-start failover. The same thing happens if a shutdown and startup of either database occurs - the service that is started is the one that matches the role of the database being started. The logs also contain other details about the actions that will be performed in case of a failover. Errors occurring for any other configuration members will not impede the switchover. Step 4: Enable Fast-Start Failover Now we are ready to enable FSFO: DGMGRL> enable fast_start failover; Enabled in Zero Data Loss Mode. You can use the maximum protection, maximum availability, or maximum The following paragraphs describe the supported availability modes. To override this behavior and allow a fast-start failover to occur if the observer is unable to contact the primary for more than FastStartFailoverThreshold seconds, set the ObserverOverride property to TRUE. See Enabling Fast-Start Failover for more information. Determining a Database's Readiness to Change Roles. See Troubleshooting Problems During a Switchover Operation for more information. Transitions the target standby database into the primary role, opens the new primary database in read/write mode, and starts redo transport services. The word ALL cannot be used as a group name because it is a reserved keyword. directory does not have the required permissions, broker does the following: When you run DGMGRL commands, if a path and file name are explicitly specified for The subdirectories that DGMGRL creates under this directory will also have the When DGMGRL starts, if the DG_ADMIN /home1/dataguard/config_NorthSales/callout/fsfocallout.ora. For example: The following example shows the fast-start failover information for the DRSolution configuration: The following SHOW OBSERVER command displays information about multiple observers in the DRSolution broker configuration. The database on which the procedure is called notifies the observer. If the protection mode was at maximum availability or maximum performance, it remains unchanged. Data Guard. FSFO builds upon a number of other Oracle technologies and features such as Data Guard, Flashback Database, and Data Guard Broker. The environment is a single instance database without any grid Infrastructure components. (Note: 11.1.0.7 adds the StaticConnectIdentifier Broker database property to allow you to specify a different service name.) Required fields are marked *. Make sure the last redo data transmitted from the Primary database was applied on the standby database. *PATCH v5 0/6] Add Toshiba Visconti Video Input Interface driver @ 2023-01-11 2:24 Yuji Ishikawa 2023-01-11 2:24 ` [PATCH v5 1/6] dt-bindings: media: platform: visconti: Add Toshiba Visconti Video Input Interface bindings Yuji Ishikawa ` (5 more replies) 0 siblings, 6 replies; 42+ messages in thread From: Yuji Ishikawa @ 2023-01-11 . Check the spelling of your keyword search. present, you must start the observer manually using the following Immediate Failovers in Configurations Using Cascaded Standbys. The only exception to this is failovers to snapshot standby databases. ConfigurationSimpleName represents This is cleared on both when the reinstatement has been completed. ensure that it has the required permissions. Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. If there is more than one registered observer, then this command returns an error; a name is required if there is more than one observer. Switchover and Manual Failover for more information about switchovers and manual failovers, respectively. Problems with automatic reinstatement are frequently due to misconfiguration, so let's look at this in a bit more detail. In maximum protection mode, an automatic failover is always possible because the Learn how your comment data is processed. This may result in data loss. Set this property for the primary and target standby database if you want the observer to use a different connect identifier than that used to ship redo data (that is, the connect identifier specified by the DGConnectIdentifier property). See Installing and Starting the Observer. Getting the Oracle Net configuration right is one of the key factors in a successful FSFO deployment. In order to maintain separation of Broker and non-Broker activity, a second static service is recommended. Reinstating the Former Primary Database in the Broker Configuration for more information about reinstatement. You can disable fast-start failover if necessary, by using the FORCE option. If the observer is unable to regain a connection to the primary database within the specified time, then the observer begins a fast-start failover provided the standby database is ready to fail over. In disaster situations where a failover is necessary, you may be more limited as to which standby database is the best one to pick up the failed primary database's activities. The observer configuration file is a text file and the syntax to define observers and groups is similar to that used in the listener.ora or tnsnames.ora files. you need to make the primary database available, first confirm that a See the "DISABLE FAST_START FAILOVER" command in Oracle Data Guard Command-Line Interface Reference for more information. lower detection times for primary database failures. Event notification and database connection failover support is available to database clients connected to local database services when a broker-managed failover occurs. Default value is 100 Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. In the media recovery phase, Flashback Database applies redo to bring the database up to the standby_became_primary_scn. Application Continuity is an Oracle Database feature that enables rapid and nondisruptive replays of requests against the database after a recoverable error that made the database session unavailable. Starting Observers as Background Processes. database (if real-time query is enabled). If there is another standby database that is available for failover, you can perform a manual failover to that standby database after you first disable fast-start failover using the FORCE option on that standby database. Set the ObserverPingInterval and These are the actions the broker performs after you start a switchover. While not strictly required, creating a wallet provides a secure way to store the credentials needed to automatically connect to the primary when starting the observer. For each observer, the V$FS_FAILOVER_OBSERVERS view provides the 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". See the START OBSERVER command for more information. drain_timeout amongst the active services. See Oracle Data Guard Concepts and Administration for more information on using the ALTER SYSTEM FLUSH REDO statement. This list contains some recommendations to obtain better performance when using fast-start failover. If the former physical standby database was running with real-time query enabled, the new physical standby database will run with real-time query enabled. Input commands are shown in shaded boxes in normal text. On the new primary database STAN, perform a SWITCH LOGFILE to start sending redo data to the standby database PRIM. Valid values are >= 100. It is not reversible. However, fast-start failover cannot occur when the target standby database is in an unobserved state. . Broker maintains these parameters by issuing ALTER SYSTEM commands as appropriate during role transitions, database startup/shutdown, and other events. FastStartFailoverLagLimit required permissions, DGMGRL reports an error. To enable fast-start failover in Cloud Control, use the Fast-Start Failover wizard. configuration file exists. 2) Switchover/Failover option is disabled on Enterprise Manager.What are the steps to enable it so that I can do Switchover/Failover operation using OEM. database is managed by Oracle Clusterware, broker directs Oracle Clusterware to In addition to setting the configuration protection mode to maximum performance, you will also need to ensure that the LogXptMode database property for both the primary and target standby database is set to ASYNC. You can optionally indicate the database health conditions that should cause fast-start failover to occur. second. If automatic reinstatement fails, the broker will log errors and the former primary database will remain in the mounted state. configuration file Note that the value of the FastStartFailoverPmyShutdown configuration property must be FALSE for the primary to stall indefinitely under these conditions. The SHOW CONFIGURATION command will show you which databases can be reinstated and which databases must be re-created. If fast-start failover is enabled you can still perform a switchover or a manual failover as long as certain conditions are met. There is no impact on your current configuration or on applications. fsfo_hostname.dat. 8.2 Private Cloud Appliance and . However, if the standby has had contact from the primary within the period of time specified by the FastStartFailoverThreshold property, the standby prevents the failover attempt. STANDBY> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; Performing a Manual Failover Task 1: Determine Which of the Available Standby Databases is the Best Target for the Failover, Performing a Manual Failover Task 2: Start the Failover, Performing a Manual Failover Task 3: Reset the Protection Mode, Performing a Manual Failover Task 4: Re-establish a Disaster-Recovery Configuration. To start the observer with DGMGRL, issue the following files are stored in subdirectories of the DG_ADMIN directory. The following conditions apply when multiple observers are registered for one configuration: When fast-start failover is enabled, one of the observers is the master observer. In this case, disable fast-start failover using the FORCE option on the target standby database. This configuration property causes the former primary database to be automatically reinstated if a fast-start failover was initiated because the primary database was either isolated or had crashed. In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. These requirements are supplemental to those described in the documents previously referenced and in the following client-specific guides: Oracle Data Provider for .NET Developer's Guide for Microsoft Windows. SQL>select sequence#, applied from v$archived_log; These are some points to consider before you begin a switchover. On the Oracle Data Guard Overview page, click Database must be reinstated. Execute the following on primary database NORTH: Execute the following on the physical standby database SOUTH: If the broker now performs a switchover or failover, it automatically starts the SALES service on the correct database, based on the database's role. FSFO can provide substantial gains in high availability and disaster recovery preparedness for all environments, from inexpensive Cloud-based systems to global distributed data centers. Stopping the Observer When There is Only One Observer. files to automate tasks that must be performed before and after a fast-start failover Install the DGMGRL command-line interface on the observer computer as described in Oracle Data Guard Installation. command on the observer computer: The observer is a continuously executing process that is directory. For example, if the old standby was a physical or snapshot standby, then the old primary must be re-created as a physical standby. directory specified by this variable does not exist, or the directory does not have the Before enabling fast-start failover, use one of the following techniques After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. There can be up to four A running observer will follow the primary automatically after a role transition, but a newly (re)started observer won't start if the initial connection is to a down database or one with an out of date or corrupted Broker config file. A database in the primary role will not open until it has verified with the observer that it is still the primary. If you have not used the SET ObserverConfigFile command after starting the current DGMGRL client, then the result will always be: ObserverConfigFile=observer.ora. Tags: Data Guard, Oracle. Create a trigger on this event to perform actions specific to your environment after a switchover or failover, such as updating the name resolution service to point to the new primary. On Windows, the directory specified by the DG_ADMIN You cannot perform a manual failover to the target standby database for the same reason. The target standby database is enabled and is in the APPLY-ON state. Regards, Narottam Tagged: dataguard dba rac Welcome! The service can be started on the physical standby only after the redo generated by starting the service has been applied. SQL> Select Database_role from v$Database; Be aware that if you issue the following manual commands on either of those databases, then both the SALESRO and SALESRW services would be started on the databases regardless of what you may have earlier specified with the SRVCTL -role qualifier. You can also specify a list of ORA- errors that will initiate FSFO failover. Contains the observer log file for the broker configuration named Relationship Between Primary, Target Standby, and Observer During Fast-start Failover. Create a unique connect alias for each database. Use the EMCLI verb dg_configure_observers. A failover to a logical standby database requires that all physical and snapshot standby databases be re-created from a copy of the new primary database after the failover completes. PRIM> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN; There are two types of failover operations: Graceful or "no-data-loss" failover and Forced or "minimal-data-loss" failover. same permissions. At this point, you can either: Disable fast-start failover (described in Disabling Fast-Start Failover) and attempt to open the former primary database, Manually reinstate the former primary database, as described in Reenabling Disabled Databases After a Role Change. Neither the primary database nor the logical standby database needs to be restarted after the switchover completes. See Manual Failover for complete information about manual failovers. When performing a failover in a configuration whose standbys are all of the same type, choose the standby database that has the smallest transport lag. The minimum fast-start failover operation, the observer checks if a fast-start failover As a result, there is no guarantee that the observer will not perform a fast-start failover to the target standby database if the observer determines that conditions warrant a failover. Facebook:https://www.facebook.com/HariPrasathdba Once the observer is started, you cannot change the file's name and location. Reinstate the original primary database to act as a standby database in the new configuration. If this operation is successful, a zero data loss failover may be possible even if the primary database is not in a zero data loss protection mode. Oracle Data Guard Broker is a utility that can help you manage your Oracle Data Guard. Before stopping an observer, note the following: The observer does not stop immediately when you issue the STOP OBSERVER command. It must appear as the first part of an observer configuration file. failover configuration file, this script is run. Verify the standby database instance is mounted. A switchover is a role reversal between the primary database and one of its standby databases. 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). The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. groups used by multiple configuration commands. If there are multiple observers, then only one of them is the master observer. the primary database and the target standby database do not have a network STANDBY>ALTER DATABASE OPEN; MASTEROBSERHOST TO command. Worked as a Development and Database Administrator. You must provide a connect identifier, through which one or more databases in a specific broker configuration can be reached. orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID. The procedure for using RMAN to create a standby database is fully explained in Appendix F of Oracle Oracle Data Guard Concepts and Administration document (10g Rel 2 and 11g Rel 1). If the service has been configured to start automatically (-policy AUTOMATIC), then the service will automatically start only after a database role change. Reinstate or re-create standby databases in the configuration that were disabled by the broker. specified, the file is stored in an appropriate directory under the broker's upheld. A switch-over allows the primary database to switch roles with its standby database. Clusterware agent that the failover completed, the Oracle Clusterware agent opens PDBs Figure 6-2 The Observer in the Fast-Start Failover Environment. Once fast-start failover is enabled, the broker will ensure that fast-start failover You can find detailed information about all observers, including master observers and backup observers, in the V$FS_FAILOVER_OBSERVERS view. You must then re-create it from a copy of the new primary database and reenable it as described in How to Re-create and Reenable a Disabled Database. Then, on the Fast-Start Failover Change Mode page, click Enabled. You can register up to four observers to monitor a single Data Guard broker configuration. Once an observer is started, no further user interaction is required. A switchover guarantees no data loss and is typically done for planned maintenance of the primary system. 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. This file is stored in the This post will demonstrate the procedure to test Oracle Data Guard Fast-Start Failover by shutting down the server where the primary database is running from. If failover occurs to a logical standby database, all physical and snapshot standby databases will be disabled by the broker. Observer uses the value of the DGConnectIdentifier property to connect to and monitor the primary and target standby databases. Broker keeps its configuration details in flat file. Reenabling Disabled Databases After a Role Change describes how to restore their viability as standby databases. connection, or the database on which you issued the disable fast-start failover Note: Data Guard requires dedicated server connections for proper operation. When you execute commands that affect multiple observers, if you have not specified a name and location for the observer configuration file, then broker searches the current working directory for a file named observer.ora. Data Guard uses Oracle Net (SQL*Net) for communication between the primary and standby databases and the FSFO observer. Testing FSFO failover requires simulating loss of the primary. Tasks that must be performed before and after a fast-start failover In this case, the primary database stalls and prevents any further transactions from Errors occurring for any other configuration members will not impede the switchover. You will have to reinstate or re-create (see Reenabling Disabled Databases After a Role Change) the standby databases after failover has completed. After the former primary database has been repaired, the observer reestablishes its connection to that database and reinstates it as a new standby database. $DG_ADMIN directory. database. You can switch back to the original Primary database later by performing another switch over. This section lists the steps the master observer takes to determine if a fast-start failover is needed and then to perform one, if necessary. If the protection mode was at maximum protection, it is reset to maximum performance. FastStartFailoverLagLimit configuration property is set to zero) or The configuration must be operating in either maximum availability mode or maximum performance mode in order to be able to switch over to a logical standby database. 4. Broker Configuration Has Multiple Registered Observers. Database dismounted. The SRVCTL utility does not automatically take the database role into account, so any time you start a service manually, you must specify the name(s) of the service you want started. It's good practice to use separate listeners for application connections and Data Guard connections. Then, on the Fast-Start Failover Configure page, select the standby database that should be the target of a failover. Colorado Brinks Truck Robbery Update,
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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. For Oracle RAC databases, see Oracle Real Application Clusters Administration and Deployment Guide for more information about configuring database services with the SRVCTL utility. It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. Note: this state also occurs on the primary during startup when fast-start failover is possible and neither the target standby database nor the observer are present to confirm it is okay to continue opening the database. Stop the observer using the DGMGRL STOP OBSERVER command. The target standby database has contact with the primary database. Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). This can happen for either of the following reasons: A bystander standby database has applied more redo data than the new primary database itself had applied when it was a standby database. gets enabled and then begins monitoring. All Data Guard environments should enable force logging at the database level in order to guard against nologging tablespaces from being added. The column value for V$DATABASE.FS_FAILOVER_STATUS will be SYNCHRONIZED in a configuration operating in maximum availability mode, and it will be TARGET UNDER LAG LIMIT in a configuration operating in maximum performance mode when ready to fast-start failover. The same thing happens if a shutdown and startup of either database occurs - the service that is started is the one that matches the role of the database being started. The logs also contain other details about the actions that will be performed in case of a failover. Errors occurring for any other configuration members will not impede the switchover. Step 4: Enable Fast-Start Failover Now we are ready to enable FSFO: DGMGRL> enable fast_start failover; Enabled in Zero Data Loss Mode. You can use the maximum protection, maximum availability, or maximum The following paragraphs describe the supported availability modes. To override this behavior and allow a fast-start failover to occur if the observer is unable to contact the primary for more than FastStartFailoverThreshold seconds, set the ObserverOverride property to TRUE. See Enabling Fast-Start Failover for more information. Determining a Database's Readiness to Change Roles. See Troubleshooting Problems During a Switchover Operation for more information. Transitions the target standby database into the primary role, opens the new primary database in read/write mode, and starts redo transport services. The word ALL cannot be used as a group name because it is a reserved keyword. directory does not have the required permissions, broker does the following: When you run DGMGRL commands, if a path and file name are explicitly specified for The subdirectories that DGMGRL creates under this directory will also have the When DGMGRL starts, if the DG_ADMIN /home1/dataguard/config_NorthSales/callout/fsfocallout.ora. For example: The following example shows the fast-start failover information for the DRSolution configuration: The following SHOW OBSERVER command displays information about multiple observers in the DRSolution broker configuration. The database on which the procedure is called notifies the observer. If the protection mode was at maximum availability or maximum performance, it remains unchanged. Data Guard. FSFO builds upon a number of other Oracle technologies and features such as Data Guard, Flashback Database, and Data Guard Broker. The environment is a single instance database without any grid Infrastructure components. (Note: 11.1.0.7 adds the StaticConnectIdentifier Broker database property to allow you to specify a different service name.) Required fields are marked *. Make sure the last redo data transmitted from the Primary database was applied on the standby database. *PATCH v5 0/6] Add Toshiba Visconti Video Input Interface driver @ 2023-01-11 2:24 Yuji Ishikawa 2023-01-11 2:24 ` [PATCH v5 1/6] dt-bindings: media: platform: visconti: Add Toshiba Visconti Video Input Interface bindings Yuji Ishikawa ` (5 more replies) 0 siblings, 6 replies; 42+ messages in thread From: Yuji Ishikawa @ 2023-01-11 . Check the spelling of your keyword search. present, you must start the observer manually using the following Immediate Failovers in Configurations Using Cascaded Standbys. The only exception to this is failovers to snapshot standby databases. ConfigurationSimpleName represents This is cleared on both when the reinstatement has been completed. ensure that it has the required permissions. Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. If there is more than one registered observer, then this command returns an error; a name is required if there is more than one observer. Switchover and Manual Failover for more information about switchovers and manual failovers, respectively. Problems with automatic reinstatement are frequently due to misconfiguration, so let's look at this in a bit more detail. In maximum protection mode, an automatic failover is always possible because the Learn how your comment data is processed. This may result in data loss. Set this property for the primary and target standby database if you want the observer to use a different connect identifier than that used to ship redo data (that is, the connect identifier specified by the DGConnectIdentifier property). See Installing and Starting the Observer. Getting the Oracle Net configuration right is one of the key factors in a successful FSFO deployment. In order to maintain separation of Broker and non-Broker activity, a second static service is recommended. Reinstating the Former Primary Database in the Broker Configuration for more information about reinstatement. You can disable fast-start failover if necessary, by using the FORCE option. If the observer is unable to regain a connection to the primary database within the specified time, then the observer begins a fast-start failover provided the standby database is ready to fail over. In disaster situations where a failover is necessary, you may be more limited as to which standby database is the best one to pick up the failed primary database's activities. The observer configuration file is a text file and the syntax to define observers and groups is similar to that used in the listener.ora or tnsnames.ora files. you need to make the primary database available, first confirm that a See the "DISABLE FAST_START FAILOVER" command in Oracle Data Guard Command-Line Interface Reference for more information. lower detection times for primary database failures. Event notification and database connection failover support is available to database clients connected to local database services when a broker-managed failover occurs. Default value is 100 Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. In the media recovery phase, Flashback Database applies redo to bring the database up to the standby_became_primary_scn. Application Continuity is an Oracle Database feature that enables rapid and nondisruptive replays of requests against the database after a recoverable error that made the database session unavailable. Starting Observers as Background Processes. database (if real-time query is enabled). If there is another standby database that is available for failover, you can perform a manual failover to that standby database after you first disable fast-start failover using the FORCE option on that standby database. Set the ObserverPingInterval and These are the actions the broker performs after you start a switchover. While not strictly required, creating a wallet provides a secure way to store the credentials needed to automatically connect to the primary when starting the observer. For each observer, the V$FS_FAILOVER_OBSERVERS view provides the 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". See the START OBSERVER command for more information. drain_timeout amongst the active services. See Oracle Data Guard Concepts and Administration for more information on using the ALTER SYSTEM FLUSH REDO statement. This list contains some recommendations to obtain better performance when using fast-start failover. If the former physical standby database was running with real-time query enabled, the new physical standby database will run with real-time query enabled. Input commands are shown in shaded boxes in normal text. On the new primary database STAN, perform a SWITCH LOGFILE to start sending redo data to the standby database PRIM. Valid values are >= 100. It is not reversible. However, fast-start failover cannot occur when the target standby database is in an unobserved state. . Broker maintains these parameters by issuing ALTER SYSTEM commands as appropriate during role transitions, database startup/shutdown, and other events. FastStartFailoverLagLimit required permissions, DGMGRL reports an error. To enable fast-start failover in Cloud Control, use the Fast-Start Failover wizard. configuration file exists. 2) Switchover/Failover option is disabled on Enterprise Manager.What are the steps to enable it so that I can do Switchover/Failover operation using OEM. database is managed by Oracle Clusterware, broker directs Oracle Clusterware to In addition to setting the configuration protection mode to maximum performance, you will also need to ensure that the LogXptMode database property for both the primary and target standby database is set to ASYNC. You can optionally indicate the database health conditions that should cause fast-start failover to occur. second. If automatic reinstatement fails, the broker will log errors and the former primary database will remain in the mounted state. configuration file Note that the value of the FastStartFailoverPmyShutdown configuration property must be FALSE for the primary to stall indefinitely under these conditions. The SHOW CONFIGURATION command will show you which databases can be reinstated and which databases must be re-created. If fast-start failover is enabled you can still perform a switchover or a manual failover as long as certain conditions are met. There is no impact on your current configuration or on applications. fsfo_hostname.dat. 8.2 Private Cloud Appliance and . However, if the standby has had contact from the primary within the period of time specified by the FastStartFailoverThreshold property, the standby prevents the failover attempt. STANDBY> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; Performing a Manual Failover Task 1: Determine Which of the Available Standby Databases is the Best Target for the Failover, Performing a Manual Failover Task 2: Start the Failover, Performing a Manual Failover Task 3: Reset the Protection Mode, Performing a Manual Failover Task 4: Re-establish a Disaster-Recovery Configuration. To start the observer with DGMGRL, issue the following files are stored in subdirectories of the DG_ADMIN directory. The following conditions apply when multiple observers are registered for one configuration: When fast-start failover is enabled, one of the observers is the master observer. In this case, disable fast-start failover using the FORCE option on the target standby database. This configuration property causes the former primary database to be automatically reinstated if a fast-start failover was initiated because the primary database was either isolated or had crashed. In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. These requirements are supplemental to those described in the documents previously referenced and in the following client-specific guides: Oracle Data Provider for .NET Developer's Guide for Microsoft Windows. SQL>select sequence#, applied from v$archived_log; These are some points to consider before you begin a switchover. On the Oracle Data Guard Overview page, click Database must be reinstated. Execute the following on primary database NORTH: Execute the following on the physical standby database SOUTH: If the broker now performs a switchover or failover, it automatically starts the SALES service on the correct database, based on the database's role. FSFO can provide substantial gains in high availability and disaster recovery preparedness for all environments, from inexpensive Cloud-based systems to global distributed data centers. Stopping the Observer When There is Only One Observer. files to automate tasks that must be performed before and after a fast-start failover Install the DGMGRL command-line interface on the observer computer as described in Oracle Data Guard Installation. command on the observer computer: The observer is a continuously executing process that is directory. For example, if the old standby was a physical or snapshot standby, then the old primary must be re-created as a physical standby. directory specified by this variable does not exist, or the directory does not have the Before enabling fast-start failover, use one of the following techniques After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. There can be up to four A running observer will follow the primary automatically after a role transition, but a newly (re)started observer won't start if the initial connection is to a down database or one with an out of date or corrupted Broker config file. A database in the primary role will not open until it has verified with the observer that it is still the primary. If you have not used the SET ObserverConfigFile command after starting the current DGMGRL client, then the result will always be: ObserverConfigFile=observer.ora. Tags: Data Guard, Oracle. Create a trigger on this event to perform actions specific to your environment after a switchover or failover, such as updating the name resolution service to point to the new primary. On Windows, the directory specified by the DG_ADMIN You cannot perform a manual failover to the target standby database for the same reason. The target standby database is enabled and is in the APPLY-ON state. Regards, Narottam Tagged: dataguard dba rac Welcome! The service can be started on the physical standby only after the redo generated by starting the service has been applied. SQL> Select Database_role from v$Database; Be aware that if you issue the following manual commands on either of those databases, then both the SALESRO and SALESRW services would be started on the databases regardless of what you may have earlier specified with the SRVCTL -role qualifier. You can also specify a list of ORA- errors that will initiate FSFO failover. Contains the observer log file for the broker configuration named Relationship Between Primary, Target Standby, and Observer During Fast-start Failover. Create a unique connect alias for each database. Use the EMCLI verb dg_configure_observers. A failover to a logical standby database requires that all physical and snapshot standby databases be re-created from a copy of the new primary database after the failover completes. PRIM> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN; There are two types of failover operations: Graceful or "no-data-loss" failover and Forced or "minimal-data-loss" failover. same permissions. At this point, you can either: Disable fast-start failover (described in Disabling Fast-Start Failover) and attempt to open the former primary database, Manually reinstate the former primary database, as described in Reenabling Disabled Databases After a Role Change. Neither the primary database nor the logical standby database needs to be restarted after the switchover completes. See Manual Failover for complete information about manual failovers. When performing a failover in a configuration whose standbys are all of the same type, choose the standby database that has the smallest transport lag. The minimum fast-start failover operation, the observer checks if a fast-start failover As a result, there is no guarantee that the observer will not perform a fast-start failover to the target standby database if the observer determines that conditions warrant a failover. Facebook:https://www.facebook.com/HariPrasathdba Once the observer is started, you cannot change the file's name and location. Reinstate the original primary database to act as a standby database in the new configuration. If this operation is successful, a zero data loss failover may be possible even if the primary database is not in a zero data loss protection mode. Oracle Data Guard Broker is a utility that can help you manage your Oracle Data Guard. Before stopping an observer, note the following: The observer does not stop immediately when you issue the STOP OBSERVER command. It must appear as the first part of an observer configuration file. failover configuration file, this script is run. Verify the standby database instance is mounted. A switchover is a role reversal between the primary database and one of its standby databases. 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). The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. groups used by multiple configuration commands. If there are multiple observers, then only one of them is the master observer. the primary database and the target standby database do not have a network STANDBY>ALTER DATABASE OPEN; MASTEROBSERHOST TO command. Worked as a Development and Database Administrator. You must provide a connect identifier, through which one or more databases in a specific broker configuration can be reached. orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID. The procedure for using RMAN to create a standby database is fully explained in Appendix F of Oracle Oracle Data Guard Concepts and Administration document (10g Rel 2 and 11g Rel 1). If the service has been configured to start automatically (-policy AUTOMATIC), then the service will automatically start only after a database role change. Reinstate or re-create standby databases in the configuration that were disabled by the broker. specified, the file is stored in an appropriate directory under the broker's upheld. A switch-over allows the primary database to switch roles with its standby database. Clusterware agent that the failover completed, the Oracle Clusterware agent opens PDBs Figure 6-2 The Observer in the Fast-Start Failover Environment. Once fast-start failover is enabled, the broker will ensure that fast-start failover You can find detailed information about all observers, including master observers and backup observers, in the V$FS_FAILOVER_OBSERVERS view. You must then re-create it from a copy of the new primary database and reenable it as described in How to Re-create and Reenable a Disabled Database. Then, on the Fast-Start Failover Change Mode page, click Enabled. You can register up to four observers to monitor a single Data Guard broker configuration. Once an observer is started, no further user interaction is required. A switchover guarantees no data loss and is typically done for planned maintenance of the primary system. 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. This file is stored in the This post will demonstrate the procedure to test Oracle Data Guard Fast-Start Failover by shutting down the server where the primary database is running from. If failover occurs to a logical standby database, all physical and snapshot standby databases will be disabled by the broker. Observer uses the value of the DGConnectIdentifier property to connect to and monitor the primary and target standby databases. Broker keeps its configuration details in flat file. Reenabling Disabled Databases After a Role Change describes how to restore their viability as standby databases. connection, or the database on which you issued the disable fast-start failover Note: Data Guard requires dedicated server connections for proper operation. When you execute commands that affect multiple observers, if you have not specified a name and location for the observer configuration file, then broker searches the current working directory for a file named observer.ora. Data Guard uses Oracle Net (SQL*Net) for communication between the primary and standby databases and the FSFO observer. Testing FSFO failover requires simulating loss of the primary. Tasks that must be performed before and after a fast-start failover In this case, the primary database stalls and prevents any further transactions from Errors occurring for any other configuration members will not impede the switchover. You will have to reinstate or re-create (see Reenabling Disabled Databases After a Role Change) the standby databases after failover has completed. After the former primary database has been repaired, the observer reestablishes its connection to that database and reinstates it as a new standby database. $DG_ADMIN directory. database. You can switch back to the original Primary database later by performing another switch over. This section lists the steps the master observer takes to determine if a fast-start failover is needed and then to perform one, if necessary. If the protection mode was at maximum protection, it is reset to maximum performance. FastStartFailoverLagLimit configuration property is set to zero) or The configuration must be operating in either maximum availability mode or maximum performance mode in order to be able to switch over to a logical standby database. 4. Broker Configuration Has Multiple Registered Observers. Database dismounted. The SRVCTL utility does not automatically take the database role into account, so any time you start a service manually, you must specify the name(s) of the service you want started. It's good practice to use separate listeners for application connections and Data Guard connections. Then, on the Fast-Start Failover Configure page, select the standby database that should be the target of a failover.
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