The new standby database is a viable target of a failover when it begins receiving redo data received from the new primary database. 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. Issue the following SRVCTL commands so that both databases in the Data Guard configuration know about the two potential services for each database: To start things up initially, you must manually start the services on the right node. It automatically sets Data Guard related database initialization parameters on instance start and role transitions, starts apply services for standbys, and automates many of the administrative tasks associated with maintaining a Data Guard configuration. The following steps all require the database to be in a mounted (not open) state. Busca trabajos relacionados con New sql server failover cluster installation greyed out o contrata en el mercado de freelancing ms grande del mundo con ms de 22m de trabajos. Sets up redo transport from the new primary to the other members of the configuration, Starts Redo Apply services on the new standby, Ensures the other standbys in the broker configuration are viable to the new primary, Integrates with Oracle Clusterware and Oracle Global Data Services (GDS) to ensure that the proper services are started after a role change. Suppose you have a primary database, BOSTON, and a standby database, CHICAGO. The time interval starts when the observer first loses its connection to the primary database. created when the START OBSERVER command is issued. You can disable fast-start failover if necessary, by using the FORCE option. the location of the observer log file, and the location of the observer runtime data Once you have completed the switchover back to the original primary, you may then reenable the physical and snapshot standby databases since they are still viable standbys for the original primary database. Keep this trigger as simple and reliable as possible, limiting it to only what is absolutely necessary at the moment of role transition, since any failures at this point may affect availability. Media Recovery - Once the restore is complete, recovery proceeds as a typical media recovery, applying redo from archived and online redologs and rolling back uncommitted changes with undo. If the primary database does not have connectivity with the target standby database, fast-start failover remains enabled on the target standby database and the observer may still attempt a fast-start failover if conditions warrant a failover. The advanced way is in the following article: Connect-Time Failover by a Dynamic Service Name. Post failover, there are two methods of rebuilding your failed primary Method 1: Rebuild from scratch -> RMAN duplicate Method 2: Flashback database -> only if Flashback was enabled Reinstate failed primary: When you use data guard broker, with just one command, the primary can be rebuilt. Make some new changes and verify that they are preserved after failover. You cannot create the standby DB system in a different AD from the primary DB system. distance. the SYSDG or SYSDBA privilege. This exercises the configuration, but triggers failover differently than losing contact with the primary. Fast-start failover is inhibited in this case. Then set the configuration protection mode to maximum availability. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM: 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. Cloud Control will start the observer. stored in the specified path using the default file names. This action may result in two databases in the configuration simultaneously assuming the primary database role should fast-start failover occur. Write Engineering Change Proposal documentation and reports to request permission to install, replace . If these parameters are modified outside of Broker, it raises a warning. Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. You can upgrade the protection mode later, if necessary, as described in Setting the Protection Mode for Your Configuration. By default, the observer will initiate failover to the target standby if and only if ALL of the following are true: Oracle Database 11g Rel 1 introduced user configurable failover conditions that can trigger the observer to initiate failover immediately. These tasks assume that you are connected as SYS or SYSDG and that a primary and standby database are already set up in a broker configuration. The list is empty by default. If the failover target database is an Oracle RAC physical or snapshot standby database, the broker directs Oracle Clusterware to restart all instances that may have been shut down prior to the failover. The old Primary must have been running in flashback mode before the failover. You can query the V$DATABASE view to verify that the observer is started and the configuration is ready for fast-start failover. If you expect the network to be disconnected for a long time and In Maximum Availability mode, FSFO guarantees that no transaction that has received a commit acknowledgment will be lost during a failover. there is a lost network connection, be aware that the observer may attempt a 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 primary database that failed or took longer than the time Note: if the observer loses contact with the primary, but the standby does not, the observer can determine that the primary is still up via the standby. Please contact us at contactus@smarttechways.com. If the former primary database cannot be reinstated automatically, you can manually reinstate it using either the DGMGRL REINSTATE command or Cloud Control. If local_listener is already in use, add the Data Guard listener to the list. For more information, see SET MASTEROBSERVER TO. The OberverPingRetry property specifies the number of This not only saves time and minimizes problems by automating an otherwise manual process, it exercises your failover and DR procedures with every flip so that you know the FSFO configuration is sound and, in a real emergency, everyone knows what to do. The only exception to this is failovers to snapshot standby databases. Provides an automatic failover While Oracle 11g's Data Guard definitely protects a database when the entire production site is lost via its failover capabilities, it's still necessary for an Oracle DBA to intervene to complete the failover process. Flashing back a database is much faster and more seamless (one simple DDL statement) than traditional point-in-time or SCN-based recovery. FastStartFailoverLagLimit property. Observers continuously monitor the fast-start failover environment to ensure the primary database is available (described in When Fast-Start Failover Is Enabled and the Observer Is Running). 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. the names of the scripts created in the previous step. Permissions Required by the DG_ADMIN Directory. Valid values are >= 10. This nomination is noted in the observer log file and in the broker log file (drc*.log). November 20, 2009. failover to the target standby database. The following is a sample observer configuration file: Since the broker configuration SALES consists of three databases, Boston, Chicago, and Dallas, with a CONNECT_ID of SALES_P, the SALES_P connect identifier must be defined such that it can reach any instance of any database within the configuration. The Oracle Database 10g FSFO observer is limited to using the default username and password defined in the wallet. Most of the network services used in a FSFO environment may use dynamic registration, but to enable Broker to restart instances during role transitions or during reinstatement after a failover, you must define a static service named db_unique_name_dgmgrl. Performing failover : Step 1: Check Standby Database role. SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH; In this mode, the FastStartFailoverLagLimit configuration property is set to zero. Fast-start failover can be used only in a broker configuration and can be configured only through DGMGRL or Cloud Control. A switchover to a physical standby database is preferable because all databases in the configuration will be available as standby databases to the new primary database after the switchover operation completes. A database in the primary role will not open until it has verified with the observer that it is still the primary. time specified by maximum configured You can start the observer before or after you enable Overview of Switchover and Failover in a Broker Environment. committing because a fast-start failover may have occurred while it was When the standby becomes available again, the primary and standby re-synchronize and resume synchronous redo transfer. For each broker configuration on which one or more fsfo_postcallout are stored in the same location as 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. 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. Note: the FSFO observer version must match the database version. Oracle Database PL/SQL Packages and Types Reference for more information about the DBMS_DG package. You can create two callout configuration scripts, a If you have an Oracle RAC primary database, consider specifying a higher value to minimize the possibility of a false failover in the event of an instance failure. Getting the Oracle Net configuration right is one of the key factors in a successful FSFO deployment. DGMGRL> show configuration Configuration - CDB01_fraad1_CDB01_fraad3 Protection Mode: MaxAvailability Members: CDB01_fraad1 - Primary database CDB01_fraad3 - (*) Physical standby database same permissions. 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). So if the original Primary database is still accessible, you should always consider a switchover first. For a system to process an instruction involving data access, these are the certain steps involved: Fetch the block of data from the hard disk (secondary/permanent storage) to the primary memory (e.g. multi-tenant environments Know the database downgrade steps in case the upgraded database isn't compatible with the environment Discover the features and benefits to the organization when it moves from the old database . Configure the TNSNAMES.ORA file on the observer system so that the observer is able to connect to the primary database and to the pre-selected target standby database. The command SHOW FAST_START FAILOVER shows a list of registered observers and indicates which one is the master. Note that a switchover operation may be started before the specified wait Note: Data Guard requires dedicated server connections for proper operation.