data guard failover steps
In maximum availability mode, set the LogXptMode database property for both the primary and target standby databases to SYNC or FASTSYNC. To move the observer to another computer: There is no need to disable fast-start failover when you move the observer. Perform SWITCH LOGFILE if necessary. 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. Databases that have been disabled after a role transition are not removed from the broker configuration, but they are no longer managed by the broker. You must also start and stop the SALESRO service on the primary so that it can be started on the standby. STAN is now transitioned to the primary database role.Now your PHYSICAL STANDBY Database has become PRIMARY. The new primary database starts transmitting redo data to the new standby database. $DG_ADMIN/config_ConfigurationSimpleName/callout You cannot perform a manual failover to the target standby database for the same reason. Each group that you define must have at least one broker configuration. Immediately after issuing command in step 2, shut down and restart the standby instance STAN: Enabling Fast-Start Failover describes how to start observers as a part of the step-by-step process to enable fast-start failover. See Choosing a Target Standby Database for helpful advice. Step 4: Enable Fast-Start Failover Now we are ready to enable FSFO: DGMGRL> enable fast_start failover; Enabled in Zero Data Loss Mode. Currently, this state can be detected only when the database is open. name of the observer log file is The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. (For example, if the DBMS_LOGSTDBY.SKIP procedure was used to specify which database operations done on the primary database will not be applied to the logical standby database.). SHOW CONFIGURATION VERBOSE, or SHOW OBSERVER Fast-Start Failover allows Data Guard to automatically failover to a previously chosen standby database without requiring manual intervention to invoke the failover. If you are more concerned about the performance of the primary database than a minimal loss of data, consider enabling fast-start failover when the configuration protection mode is set to maximum performance. DGMGRL. Bounce your database and verify database name its open mode and its role: SQL> shutdown immediate; ORA-01109: database not open Database dismounted. Other logical standby bystander databases in the broker configuration will remain viable after the switchover. It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. The values that indicate FSFO is ready for failover are listed below. Use the VALIDATE STATIC CONNECT IDENTIFIER command to ensure the static services have been configured correctly. Note: If you have just enabled archivelog mode, force an archive log creation ( alter system archive log current) to ensure that at least one archive log exists. The configuration status returns the SUCCESS status after the observer reestablishes its connection to the primary database, which then notifies the target standby database. Add the wallet location and override to sqlnet.ora. The following example displays the contents of the fast-start failover Automatic failover is optional and can be enabled or disabled on your Autonomous Container Databases with Autonomous Data Guard. Credentials Required for Access to Broker Configurations. After step 3 completes, you can open the new Primary database STAN: Setting it to 'FALSE' leaves the database open and stalled until it is terminated or signaled to proceed in the event a failover did not take place (e.g. 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. For example, if all your physical standbys are also unavailable, then failing over to a logical standby is your only choice. Broker will validate the configuration, set parameters on both databases, and start managed recovery. FastStartFailoverLagLimit property. If errors occur during the disable operation, the broker returns an error message and stops the disable operation. For example: The default value for the FastStartFailoverThreshold property is 30 seconds and the lowest possible value is 6 seconds. Only the observer can initiate FSFO failover. We will create 4 SRLs starting with group# 11. Overall commit latency is increased by the round-trip network latency. environment variable to specify the default location for client-side broker files. To change the FastStartFailoverTarget property to point to a different standby database, disable fast-start failover, set the FastStartFailoverTarget property, and reenable fast-start failover. You can query the V$FS_FAILOVER_STATS view on the primary database to display statistics about fast-start failovers that have occurred on the system. What is true about Data Guard setup with fast-start failover? 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. How to Implement Fast-Start Failover 11g - Ed Chen Logic If this occurs, run 'stop observer' and try again. STAN is now transitioned to the primary database role.Now your PHYSICAL STANDBY Database has become PRIMARY. redo generation on the primary database will be stalled. Disaster Recovery with Oracle Data Guard - online presentation Group definition this section is optional. The default group is all the configurations defined in the observer configuration file. Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. The new primary database is opened in read/write mode and redo transport services are started. This property also affects whether the broker skips viability checks of bystander standby databases when a fast-start failover occurs. Except for testing purposes, it is not recommended that you start more than one observer on the same host for a Data Guard broker configuration. In case of worst situation with data guard primary database, or not available for production than we can activated standby database as a primary production database. To allow the master observer to automatically reinstate the former primary database, the database must be started and mounted. DGMGRL> show configuration Configuration - CDB01_fraad1_CDB01_fraad3 Protection Mode: MaxAvailability Members: CDB01_fraad1 - Primary database CDB01_fraad3 - (*) Physical standby database Check the database role,open_mode in standby server. [PATCH V3 0/6] ASoC: codecs: Add Awinic AW883XX audio amplifier driver Performing Database Failover with Oracle 11g Data Guard All Data Guard environments require the use of a password file in order to allow the databases to connect to each other. Verifies that the target standby database is enabled. the observer was killed after the stall began, but before the failover timeout had elapsed). It is then configured to be active in the PHYSICAL_STANDBY role on the physical standby database SOUTH. For switchovers, understanding all of the factors can simplify the choice of which standby database to consider as your new primary database. collections and databases Set up replica sets and automatic failover in MongoDB Use sharding to scale horizontally, and learn how . Initiate the failover on the standby database STAN: SQL>connect /@STAN as sysdba SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH; SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; 2. If groups are not defined, you can still operate on all configurations defined in the file as a whole. If the database is managed by Oracle Clusterware, broker does not open any pluggable This is typically done for planned maintenance of the primary system. (It is permissible to change the RedoRoutes property on all standby databases including target standby databases. Both Cloud Control and the DGMGRL CLI will do this automatically as part of failover. Theoretically, this method can be used when a data guard failover occurred between the primary and standby database, but not a switchover. The committing because a fast-start failover may have occurred while it was observer computer is returned to you so that you can continue to Configure Data Guard Broker to manage and monitor the Data Guard configuration. orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID. Use the SHOW CONFIGURATION BystandersFollowRoleChange command to see the value of this property. operation: Example 6-1 Fast-start Failover Configuration miliseconds. If there are physical or snapshot standby databases in the configuration and the switchover occurs to a logical standby database, you need to re-create those databases from a copy of the new primary database and then reenable those databases, as described in Reenabling Disabled Databases After a Role Change. You cannot create the standby DB system in a different AD from the primary DB system. It is then started and stopped on the primary database. PRIM>STARTUP MOUNT; The minimum detection time is 6 seconds, which is the default Initiate the switchover on the primary database PRIM: an alias of the broker configuration name. RMAN will copy the spfile from the primary, so this init.ora file is only needed during the first phase of the duplication. Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. A fast-start failover occurred because a user-configurable condition was detected or was requested by an application by calling the DBMS_DG.INITIATE_FS_FAILOVER function. learning with R and Python are also covered in this step-by-step tutorial. Oracle Database 11g observers are incompatible with 10g databases and vice-versa. When fast-start failover is enabled, the primary and standby randomly choose one of the registered observers to be the master. To configure fast-start failover in observe-only mode: Fast-start failover will not be triggered if the primary or standby database is shut down normally. Additionally, the new master observer is identified in the output shown for the SHOW FAST_START FAILOVER and SHOW OBSERVER commands. connectivity with target standby. To start an observer as a background process, use the DGMGRL If there is more than one standby database in the configuration, you must explicitly set the FastStartFailoverTarget property on the primary database to name one or more candidate target standby databases. Step-by-step instructions for manual reinstatement are described in Reenabling Disabled Databases After a Role Change. ORACLE-BASE - Data Guard The command SHOW OBSERVER provides detailed information about registered observers. Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A LinkedIn:https://www.linkedin.com/in/hari-prasath-aa65bb19/ When querying the V$DATABASE view, pay special attention to the following: The FS_FAILOVER_STATUS column, which can contain the values described in Table 6-2. This walkthrough uses Maximum Availability mode to achieve "zero data loss". Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). If the primary or target standby databases lose connections to all backup observers, then the broker does not try to nominate a backup observer as the new master observer, and the broker reports that the configuration is not observed. Flashback Database records the before-image of changed blocks. Otherwise, they must be re-created from a copy of the new primary database. The Oracle Database 10g FSFO observer is limited to using the default username and password defined in the wallet. the primary and target standby databases. fast-start failover to the target standby database if conditions warrant a failover. This document describes how to setup clients to connect to Data Guard databases (primary and standby) and configure automatic client failover such that in case there is role change due to switchover or . may allow the primary database to continue redo generation after Moorestown, New Jersey, United States. JAVA applications can use FAN programmatically by using the JDBC FAN application programming interface to subscribe to FAN events and to execute event handling actions upon the receipt of an event. fsfocallout.ora and they have the required permissions. ob2-host can be a master observer when This may result in two databases in the configuration simultaneously assuming the primary database role. Errors occurring for any other configuration members will not impede the switchover. After a complete failover finishes, any bystander standby database that is not viable as a standby for the new primary database will be disabled by the broker. A number of prerequisites must be met on the primary in order to use Fast-Start Failover. Example 6-2 Sample Observer Configuration File. If it's not, DGB will not allow the failover to continue until the DBA has manually resolved any discrepancies. 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. observer_hostname.log. SET ObserverConfigFile used to specify a customized observer configuration file. As described in theFlashback Database section, Flashback Database takes place in two stages: a restore stage and a media recovery stage. These are some points to consider before you begin a switchover. How To Configure Client Failover For Data Guard Connections - Oracle When a fast-start failover occurs because either a user configurable fast-start failover condition is detected or an application initiates a fast-start failover by calling the DBMS_DG.INITIATE_FS_FAILOVER function, the former primary database is always shut down and never automatically reinstated. The pre-callout script How to switch roles in Oracle Data Guard - The Geek Diary START OBSERVING [cfg_group_name] starts a new observer for each broker configuration in the specified group. US Coast Guard Auxiliary. 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. This section describes how to configure and verify each prerequisite. Note that role changes to logical standby databases always result in physical standby database bystanders being disabled. 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). In this case, the FS_FAILOVER_STATUS and FS_FAILOVER_OBSERVER_PRESENT columns will appear as shown in the following table and fast-start failover will not occur: Oracle Database Reference for more information about the V$DATABASE view. Bystanders are part of the Data Guard configuration, but not part of the FSFO configuration. drain_timeout amongst the active services. Reinstatement will have to be accomplished by other means (manual or scripted Broker commands). Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A Complete Hands On Lab Practice To Manage A Data Guard . Immediately after issuing command in step 2, shut down and restart the standby instance STAN: To reenable broker management of these databases, you must reinstate or re-create the databases using one of the following procedures: If a database can be reinstated, the database will show the following status: Reinstate the database using the DGMGRL REINSTATE DATABASE command or the reinstate option in Cloud Control, as described in How to Reinstate a Database. Do not use Shared Server (formerly MTS) for Data Guard. If the database is managed by Oracle Clusterware, broker does not open any of the FastStartFailoverLagLimit Before beginning a failover, first determine that there is no possibility of recovering the primary database in a timely manner, and ensure that the primary database is shut down. See Reenabling Disabled Databases After a Role Change. Commands For Managing Observers on Multiple Configurations. Run the RMAN utility and connect to the target (primary) and auxiliary (new standby). If the observer is unable to regain a connection to the primary database within the specified time, and the target standby database is ready for fast-start failover, then fast-start failover ensues. For example, to determine if fast-start failover can occur, the FS_FAILOVER_STATUS column displays either SYNCHRONIZED or TARGET UNDER LAG LIMIT and the FS_FAILOVER_OBSERVER_PRESENT column displays YES for the target standby database. This property allows you to specify a priority ordered After an immediate failover completes, all the standby databases in the configuration, regardless of their type, are disabled. The syntax for the optional definition of a broker configuration group is: The group definition section is optional. Do this prior to every failover test. Any broker configuration name that is referred to must exist in the configuration declaration section. file (fsfo.dat). Event notification and database connection failover support is available to database clients connected to local database services when a broker-managed failover occurs. The primary database, it attempts to disable fast-start failover on as many databases in the configuration with which it has a network connection. You must provide a connect identifier, through which one or more databases in a specific broker configuration can be reached. The FastStartFailoverThreshold time interval starts when the observer first detects there might be a failure with the primary database. In this case, Flashback Database cannot be used to reinstate databases. The master observer uses the value specified by either the DGConnectIdentifier or ObserverConnectIdentifier database properties to connect to the primary and fast-start failover target standby databases. Broker changes database parameters during startup and role transitions via ALTER SYSTEM commands. The logs also contain other details about the actions that will be performed in case of a failover. For more information, see SET MASTEROBSERVER TO. The primary database must be running in order to start the observer. observer name, host, whether it is the master observer, when it became the master Oracle Database 10g allows a different password file to be used as long as the SYS passwords are the same on the primary and standby. If both HVR and Data Guard were running without latency or if no changes were made to the source database at the time of the failover, it can be assumed that all databases are synced and the no extra steps are necessary; the steps for Graceful Failover can be followed. It's generally a good idea to store the state file in a directory associated with the database to avoid locking issues when running multiple observers on the same host. These These facilities allow applications written to take advantage of them to receive asynchronous notification of database events, including role transitions. Table 6-1 Content of Default Directory for Client-side Files, Contains the observer configuration file that is used by For the RMAN duplicate active database method, the init.ora file (initdb1.ora in the example) requires only one parameter: db_name (it doesn't even have to be the real name of the database - any name will do). The FastStartFailoverTarget configuration property on the primary unless the new property value contains the current fast-start failover target. The following is an example of setting the LogXptMode property: Alternatively, use the RedoRoutes property to set the redo transport mode for the target standby and database that is currently in the primary role. primary database. There are normally two situations when this operation will be performed: a planned outage for maintenance of the primary database or disaster recovery. If a fast-start failover was initiated because the primary database had crashed or lost connectivity with the master observer and target standby database, then the master observer automatically attempts to reinstate the former primary database as a standby database, if the FastStartFailoverAutoReinstate configuration property is set to TRUE. property. MASTEROBSERHOST TO command. Disabling fast-start failover does not stop the observer. To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE. If there are no registered observers when fast-start failover is enabled, then the first observer started is designated as the master observer, and all others started later are backup observers. instructions for the DGMGRL command-line interface. After the broker receives the STOP OBSERVER request, the request is passed to the observer the next time the observer contacts the broker, and the observer then stops itself. Oracle 19c-Step by Step Manual Data Guard Failover The services required on the primary database are: Log Writer Process (LGWR) - Collects redo information and updates the online redo logs. services. If the status is SUCCESS, you're ready to start testing role transitions. Were sorry. command does not have a network connection to the primary database. Fast-start failover can be used only in a broker configuration and can be configured only through DGMGRL or Cloud Control. 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 a manual failover, you convert a standby database to a primary database because the original primary database failed and there is no possibility of recovering the primary database in a timely manner. restart the new physical standby database. The broker reinstates the database as a standby database of the same type as the former standby database of the new primary database. The FORCE option may be the preferred method for disabling When this property is set to NONE, the broker will disable all bystander standby databases without checking whether they have applied more redo data than the new primary database. The value specified for either of these properties should allow the master observer to connect to any instance of an Oracle RAC database. In order to accommodate all load conditions, Oracle recommends having at least one more SRL group than the number of ORL groups of the same size. FB Group:https://www.facebook.com/groups/894402327369506/ The broker disables all of the physical and snapshot standby databases in the configuration. By default, the observer creates this file in the current working directory when it is started and names the file fsfo.dat. After FSFO is enabled, Broker will continue to check that Flashback Database is enabled during health checks. The steps in this section describe the tasks involved to perform a manual failover. Oracle Corporation recommends that you specify this type of failover. Reinstating the Former Primary Database in the Broker Configuration for more information about reinstatement. Oracle Data Guard can switch a standby database to the primary role in case a production database becomes unavailable due to . database (if real-time query is enabled). This can be done regardless of whether the failover was done to a physical, logical, or snapshot standby database. To verify this change, again query the Database_role column of V$DATABASE. Disabling Fast-Start Failover Using Cloud Control. callout configuration file. Oracle FAN with Oracle Data Guard but without using Oracle Grid/ RAC This is normal. DGMGRL can be used to manage multiple observers in a group of broker configurations. In the restore stage, Flashback Database restores the database to a point prior to the standby_became_primary_scn using the before-image blocks in the Flashback Database logs. Problems with automatic reinstatement are frequently due to misconfiguration, so let's look at this in a bit more detail. See the Oracle Maximum Availability Architecture technical briefs at: When setting the FastStartFailoverLagLimit configuration property, consider these tradeoffs between performance and potential data-loss: A low lag limit will minimize data loss but may impact the performance of the primary database. Don't initiate failover unless at least 30 minutes of history is available. If there is only one observer, then it is considered to be the master observer. 5. Use the callout configuration file and script Staff support, hardware and software, security (both software and site), network connections, and bandwidth should be equivalent at both sites. The group of broker configurations to be managed is declared in the observer configuration file. This is called failover. Choosing a Target Standby Database for Switchover and Choosing a Target Standby Database for Failover provide guidelines to help you choose a target standby database. However, you do have the option of specifying a name and location for the observer configuration file. In the event of a Add an entry to the oratab file for the standby, db1:/u01/app/oracle/product/11.1.0/db_1:Y. fast-start failover operation, the observer checks if a fast-start failover upheld. They must be re-created from a copy of the new 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. FastStart Failover Ensues: Disaster strikes the primary database and its network connections to both the observer and the target standby database are lost. FastStartFailoverLagLimit property. Starting the Observer as a Background Process Using Stores files related to the observer and callout configuration. The default Note that enabling FSFO does not make the configuration ready for automatic failover - that requires an observer, which we'll get to next. Oracle Data Guard 11gR2 Administration : Beginner's Guide 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.