data guard failover stepsdata guard failover steps

For this build, we will use a single physical standby database. Running a StatusReport on the primary should verify that the error is due to a missing observer. The subdirectories that DGMGRL creates under this directory will also have the STANDBY>ALTER DATABASE OPEN; The observe-only mode for fast-start failover enables you to test how fast-start failover will work in your environment. Whether you reinstate or re-create a database depends on whether you performed a switchover or failover, on the type of standby database that was the target of the operation, and on whether or not there are sufficient flashback logs. Clusterware agent that the failover completed, the Oracle Clusterware agent opens PDBs An observer process is integrated in the DGMGRL client-side component of the broker and typically runs on a different computer from the primary or standby databases and from the computer where you manage the broker configuration. 1 second. The physical and snapshot standby databases will have to be re-created from a copy of the new primary database. If the DG_ADMIN environment variable is not defined, or the In such a case, no attempt is made to transmit any unsent redo from the cascader to the terminal standby. The Column Value in the following table is consistent across instances in an Oracle Real Applications Clusters (Oracle RAC) environment. PRIM>connect /@PRIM as sysdba The guide makes few assumptions about your existing environment and includes examples for creating a physical standby database and Data Guard Broker configuration. Upon detecting the break in communication, the observer attempts to reestablish a connection with the primary database for the amount of time defined by the FastStartFailoverThreshold property before initiating a fast-start failover. Read-Only Standby and Active Data Guard While this eliminates the processing overhead associated with periodically establishing a new observer connection to the primary database, it also prevents the observer from detecting that it is not possible to create new connections to the primary database. SQL>SHUTDOWN IMMEDIATE; It is possible to manually perform a completer failover to a standby database that receives redo data from a far sync instance. Contains the observer log file for the broker configuration named the ObserverPingRetry and ObserverPingInterval properties to achieve This specifies how often the observer establishes a new connection to the primary database. However, if you want the observer to reconnect to the primary database periodically as a means of testing the health of the network connection to the primary, then use the ObserverReconnect configuration property. Another good test is to simulate network failures that leave the primary up, but isolated from the failover target standby and the observer. This article - the seventh in this ongoing . The broker will not allow a switchover to a standby that has an apply delay configured (DelayMins property is set to a non-zero value). If the primary database can be mounted, it may be possible to flush any unsent redo data from the primary database to the target standby database using the ALTER SYSTEM FLUSH REDO SQL statement. Remote login is required, along with a password file, to allow the databases in a Data Guard configuration to connect to each other. In an Oracle Data Guard configuration, the SRVCTL -startoption for a standby database is always set to OPEN after a switchover. It uses these databases as a copy of the . Click Disable in the Fast-Start Failover wizard. This database property is used to specify how the observer should connect to and monitor the primary and standby database. If provided, then each group needs to have at least one broker configuration declared in the second part. During an immediate failover, the broker performs the failover steps described in How the Broker Performs an Immediate Failover Operation. There are normally two situations when this operation will be performed: a planned outage for maintenance of the primary database or disaster recovery. alter database recover managed standby database cancel; Step:3 The below commands will help to bring up standby as primary. Oracle Data Guard configuration with DGMGRL. Although redo transfer is synchronous, Maximum Availability mode allows the primary to remain available if the standby database becomes unavailable for any reason (e.g. If the designated fast-start failover target develops a problem and cannot be the target of a failover, then the broker automatically changes the fast-start failover target to one of the other candidate targets. You can switch back to the original primary and then either retry the switchover to the original target standby, or choose another standby in the configuration to switch over to. To enable fast-start failover, both the primary and target standby databases must be running and have connectivity, and satisfy all of the prerequisite conditions listed in Prerequisites for Enabling Fast-Start Failover. Check the database role,open_mode in standby server. 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. In an Oracle Data Guard configuration, the SRVCTL -startoption and -role are updated after switchover to reflect the current open mode and database role on the new primary and standby databases. ASYNC. Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A Reenabling Disabled Databases After a Role Change describes how to restore their viability as standby databases. on ob3-host and ob4-host will not The examples shown in this section do not necessarily show the specific attributes you might need to use in your own environment. Immediate: No additional data is applied on the standby database, resulting in a data-loss . 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. Were sorry. The failed primary database requires reinstatement as a new standby database to the new primary. See START OBSERVER IN BACKGROUND for more information Be sure to include the Data Guard listener in the local_listeners database parameter. Restore - Flashback Database restores the datafiles to the closest snapshot prior to the specified SCN. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM: the location of the observer log file, and the location of the observer runtime data Notice that the terminal session appears to hang after starting the observer. The behavior of the broker if the master observer fails depends on whether the broker configuration has one observer or multiple observers. if the observer is not running, The master observer and the target standby database are inconsistent with regard to the current state of the broker configuration, If the protection mode is maximum availability or maximum protection and the target standby database was not synchronized with the primary database at the time the primary database failed, If the protection mode is maximum performance and the apply point of the target standby database lags the redo generation point of the primary database by more than the amount specified by the FastStartFailoverLagLimit configuration property at the time the primary database failed. the primary role, use the PreferredObserverHosts Now your old standby database is become primary database, it is highly recommended to consider immediate full backup of primary database. Data Guard Failover Options - dba-oracle.com Presetting database properties related to redo transport services, such as LogXptMode, NetTimeout, StandbyArchiveLocation, StandbyAlternateLocation, and RedoRoutes. Figure 6-1 shows the relationships between the primary database, target standby database, and observer during fast-start failover: Before Fast-Start Failover: Oracle Data Guard is operating in a steady state, with the primary database transmitting redo data to the target standby database and the observer monitoring the state of the entire configuration. However, there may be exceptions to the recommendation to choose a physical standby database as the target standby database. RAM). name of the observer log file is Enabling Fast-Start Failover Task 1: Determine Which of the Available Standby Databases is the Best Target for the Failover, Enabling Fast-Start Failover Task 2: Specify Target Standbys with the FastStartFailoverTarget Configuration Property, Enabling Fast-Start Failover Task 3: Determine the Protection Mode You Want, Enabling Fast-Start Failover Task 4: Set the FastStartFailoverThreshold Configuration Property, Enabling Fast-Start Failover Task 5: Set Other Properties Related to Fast-Start Failover (Optional), Enabling Fast-Start Failover Task 6: Enable Additional Fast-Start Failover Conditions (Optional), Enabling Fast-Start Failover Task 7: Using DGMGRL or Cloud Control, Enabling Fast-Start Failover Task 8: Start the Observer, Enabling Fast-Start Failover Task 9: Verify the Fast-Start Failover Environment. This walkthrough assumes that all ORLs and SRLs on the primary and standby databases are the same size. The PeopleSoft application servers will react accordingly to FAN events If you will be using RMAN to create the standby database, it also needs a static service to restart the database being created. A failover to a physical standby database is preferable because it is likely that all standby databases in the configuration will still be available as standby databases to the new primary database after the failover operation completes. The price for this guarantee is increased commit latency ( log file sync waits). DGMGRL> show configuration Configuration - CDB01_fraad1_CDB01_fraad3 Protection Mode: MaxAvailability Members: CDB01_fraad1 - Primary database CDB01_fraad3 - (*) Physical standby database 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). During failover, bystanders "follow" the primary by default, flashing back and reapplying redo from the new primary as necessary. The time interval starts when the observer first loses its connection to the primary database. A simple example for *nix is provided below that will work with both releases. You must re-create the database manually from a copy of the current primary database and then reenable the database in the broker configuration. Learn how your comment data is processed. The syntax for the configuration declaration is: The definition for each broker configuration is: The configuration-name can be different from the name defined in the metadata of the Data Guard Broker configuration. 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. ZERO DATA LOSS: Fast-start failover is enabled with zero data loss. 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. CONNECT command. Fast-Start Failover in Data Guard Environments on Oracle Cloud Expected output is shown in blue text. When you configure data guard using OCI console, the default mode is set to maxprotection. A complete failover is the recommended and default failover option. You can issue a 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. Opens the new primary database in read/write mode. Set the FastStartFailoverThreshold property to specify the number of seconds you want the observer and target standby database to wait (after detecting the primary database is unavailable) before initiating a failover. 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. [PATCH v5 0/6] Add Toshiba Visconti Video Input Interface driver The environment is a single instance database without any grid Infrastructure components. There is little risk in enabling Flashback Database to determine its storage requirements - it can be disabled while the primary is open if necessary. To start the observer with DGMGRL, issue the following These are some points to consider before you begin a switchover. It is also supported for fast-start failover to physical standbys in maximum availability data protection mode. 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. Enabling Fast-Start Failover describes how to start observers as a part of the step-by-step process to enable fast-start failover. 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. A failed ping is a ping to Have a means of notifying someone if standby apply falls too far behind. SHOW OBSERVER command to confirm that the switch took place. The following sections describe how to perform manual failovers: Reenabling Disabled Databases After a Role Change. A switchover is a role reversal between the primary database and one of its standby databases. STOP OBSERVING [cfg_group_name] stops LOCAL observers running on this host (where this DGMGRL is running) for all broker configurations in a specified group. If the DG_ADMIN environment variable is not set, or the The broker selects a target standby based on the order they are specified in the property. Set both these properties to achieve a primary failure detection time of 1 Follow the guidelines described in Choosing a Target Standby Database. To stop the observer when fast-start failover is disabled, the primary database must be running. If the value is non-zero, failover is possible any time the standby database's apply To do this, use the SET ObserverConfigFile and SHOW ObserverConfigFile commands. With a value of TRUE for this property, the primary will shut down after being stalled for the number of seconds specified by the FastStartFailoverThreshold property. See Oracle Data Guard Concepts and Administration for information about tuning the log apply rate for a physical standby database. the primary database that failed or took longer than the time