data guard failover steps
There are normally two situations when this operation will be performed: a planned outage for maintenance of the primary database or disaster recovery. DGConnectIdentifier, "Scenario 9: Performing a Switchover Operation" for an example of using the VALIDATE DATABASE command to show a database's readiness to complete a role switchover, "Scenario 10: Performing a Manual Failover Operation" for an example of using the VALIDATE DATABASE command to show a database's readiness to complete a role failover. FastStartFailoverThreshold for reference information about the FastStartFailoverThreshold property. an alias of the broker configuration name. See the Oracle Reference and Data Guard Administrator guides for your release for details. standby database is mounted, broker remembers this setting. enabling fast-start failover. Tags: Data Guard, Oracle. file, observer runtime data file (fsfo.dat), fast-start failover callout In this case, no attempt is made to transmit any unsent redo from the far sync instance to the target physical standby prior to converting the physical standby into a primary database. This may take a few minutes. The observer's main purpose is to enhance high availability and lights out computing by reducing the human intervention required by the manual failover process that can add minutes or hours to downtime. But before enabling Flashback Database, you must enable Flash Recovery Area (FRA). Enabling Fast-Start Failover describes how to start observers as a part of the step-by-step process to enable fast-start failover. The connect descriptor must contain the SERVICE_NAME parameter in either case. If a group name is not specified, then SHOW OBSERVERS alone is also a valid command. Note the following points about the observe-only mode: The primary database can enter UNSYNC or LAGGING state without an acknowledgement from the observer or target standby. If the service has been configured to start automatically (-policy AUTOMATIC), then the service will automatically start only after a database role change. To start an observer, you must be able to log in to DGMGRL with an account that has ORACLE-BASE - Data Guard In this mode, no actual changes are made to your Broker configuration. 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 configuration status returns the SUCCESS status after the observer reestablishes its connection to the primary database, which then notifies the target standby database. In the following example, ObserverReconnect is set to 30 seconds. The time interval starts when the observer first loses its connection to the primary database. SQL>connect /@STAN as sysdba There are many examples, and Ritesh Chhajer offers this example of doing a Data Guard switchover using dgmgrl: 1. configuration named ConfigurationSimpleName. The physical and snapshot standby databases will have to be re-created from a copy of the new primary database. To do this, use the SET ObserverConfigFile and SHOW ObserverConfigFile commands. The first step in reinstatement is to flash the database back to the SCN where the standby became the primary (v$database.standby_became_primary_scn on the new primary). 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. Choose a value high enough to avoid false disconnects from intermittent network trouble. prolonged stall, either the observer or target standby database Es gratis registrarse y presentar tus propuestas laborales. Verifies that the target standby database is enabled. Examples of starting observers using DGMGRL are included in Scenario 6: Enabling Fast-Start Failover and Starting the Observer. 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. specified, the file is stored in an appropriate directory under the broker's How to switch roles in Oracle Data Guard - The Geek Diary Displays when the primary and target standby databases are synchronized and the configuration is operating in maximum availability mode. Subsequent changes to the same block during the same snapshot are not recorded. Add the SRLs. failover with the FORCE option on the primary database. 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. Credentials Required for Access to Broker Configurations. Were sorry. The VALIDATE FAST_START FAILOVER command parses the callout 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. There can be up to four observers for a single Data Guard configuration. Oracle 12c-Step by Step Manual Data Guard Switchover, Manual Upgrading Oracle Database From 11.2.0.4 to 12.2.0.1, Automatically Terminated The Blocking Session By Setting MAX_IDLE_BLOCKER_TIME, Apply Patching On Oracle 21c Database Release Update 21.7.0.0.0, Oracle 21c Point In Time Recovery of Pdb Database, Oracle 21c Cloning a PDB Database Using Sqldeveloper Tool. The reduced need for manual intervention can increase availability without increasing management costs. If the database is managed by Oracle Clusterware, broker does not open any pluggable 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. Apply services on all other bystander standby databases automatically begin applying redo data received from the new primary database. To use a far sync instance with fast-start failover, the far sync instance transport mode must be set to either SYNC or FASTSYNC and the target standby database transport mode must be set to ASYNC. 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. Use the EMCLI verb dg_configure_observers. property. If it exists, and it contains a pre-callout script location, Manual Failover in Data Guard - ORACLE-HELP Running a StatusReport on the primary should verify that the error is due to a missing observer. Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). fast-start failover succeeds, if a post-callout script is specified in the fast-start To maximize the benefits of FSFO, the observer should run on a different host than the primary and standby databases. The RedoRoutes property on the primary if the new value would result in the primary not being able to ship redo to the current fast-start failover target standby. It is not reversible. 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. Disable fast-start failover using the DGMGRL DISABLE FAST_START FAILOVER command. This page will not allow you to alter the protection mode. callout configuration scripts fsfo_precallout and Whereas a switchover to a logical standby database will invalidate and disable all of the physical and snapshot standby databases in the configuration. We'll start with switchovers. Start the Data Guard listener on both "a" and "b" hosts. If the target standby database is a snapshot standby database, all of its instances must be restarted to the mount mode before performing failover. The example uses the FROM ACTIVE DATABASE clause introduced in 11g that allows RMAN to create a standby database by copying the primary across the network without the need to store the backup files on disk or tape. Ensure SPFILE is used SQL> sho parameter spfile 2. 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. Disaster Recovery with Oracle Data Guard - online presentation Step-by-step instructions for manual reinstatement are described in Reenabling Disabled Databases After a Role Change. This section describes how to configure an Oracle Net connect descriptor that meets this requirement. Restarts the new standby (former primary) database if the switchover occurs to a physical standby database, and Redo Apply begins applying redo data from the new primary database. For Oracle Database Release 12.2 and higher, Oracle Enterprise Manager Cloud Control (Cloud Control) supports configuring multiple observers using the Enterprise Manager Command Line Interface (EM CLI). The NetTimeout property specifies the number of seconds LGWR will block waiting for acknowledgment from the standby in synchronous mode before considering the connection lost (corresponds to the NET_TIMEOUT option of log_archive_dest_n). Issue the following command while connected to any database in the broker configuration, except the database that is to be reinstated: The newly reinstated standby database will begin serving as a standby database to the new primary database. If possible, confirm that fast-start failover has not created when the START OBSERVER command is issued. The following steps all require the database to be in a mounted (not open) state. Then, After step 3 completes, you can open the new Primary database STAN: Now your old standby database is become primary database, it is highly recommended to consider immediate full backup of primary database. Data Guard broker does not manage or store credentials. See the START OBSERVER However, failover is attempted if the ObserverOverride configuration property is set to TRUE. Standby databases not involved in the switchover (known as bystander standby databases) continue operating in the state they were in before the switchover occurred and will automatically begin applying redo data received from the new primary database. You can use this information to identify ahead of time any redo transport configurations that would be incorrect after a role change, including any standbys that will not receive redo because the RedoRoutes property was not configured correctly. The following list indicates the extent to which fast-start failover is disabled in the broker configuration when the DISABLE FAST_START FAILOVER FORCE command is issued on the primary database, target standby database, and a standby database that is not the fast-start failover target. fsfo_postcallout are stored in the same location as See Directing a Fast-Start Failover From an Application). The FastStartFailoverThreshold time interval starts when the observer first detects there might be a failure with the primary database. observer, whether it is currently connected to the primary and target standby databases, In this example, there are 3 ORLs with a max group# of 3. If the FastStartFailoverPmyShutdown configuration property is set to TRUE, then the former primary database will have been automatically shut down and must be manually restarted before the master observer can attempt to reinstate it. observer name, host, whether it is the master observer, when it became the master MASTEROBSERHOST TO command. Waits for the target standby database to finish applying any unapplied redo data before stopping Redo Apply (if the target is a physical standby database) or SQL Apply (if the target is a logical standby database). The following is an example of starting an observer as a background process: The START OBSERVER IN BACKGROUND command uses Oracle wallet to obtain credentials to log into the database server and register observers. You can specify particular conditions for which a fast-start failover should occur using either Cloud Control or the DGMGRL ENABLE FAST_START FAILOVER CONDITION and DISABLE FAST_START FAILOVER CONDITION commands. The broker selects a target standby based on the order they are specified in the property. 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. As described in theFlashback Database section, Flashback Database takes place in two stages: a restore stage and a media recovery stage. You When you are experiencing network disconnections and you issue the DISABLE FAST_START FAILOVER FORCE command on the primary database or a standby database that does not have connectivity with the primary database, fast-start failover may not be disabled for all databases in the broker configuration. If fast-start failover is enabled, then a switchover can be performed only to the pre-specified target standby database and only if the standby database is synchronized with the primary database or is within the configured lag limit, for the max availability and max performance modes respectively. committing because a fast-start failover may have occurred while it was Simply use DISABLE FAST_START FAILOVER. Use the VALIDATE STATIC CONNECT IDENTIFIER command to ensure the static services have been configured correctly. SWITCHOVER command, and the databases are managed by Oracle If a failure occurs once a reinstatement operation (automatic or manual) is underway, the broker logs the appropriate information in the broker configuration files and broker log files. Each observer has its own log file. Note that role changes to logical standby databases always result in physical standby database bystanders being disabled. For more information, see START OBSERVER IN BACKGROUND. If the configuration is not failable, the DBMS_DG.INITIATE_FS_FAILOVER function returns an ORA error number (it does not signal an exception) informing the caller that a fast-start failover could not be performed. To verify the readiness of the fast-start failover configuration, issue the DGMGRL SHOW CONFIGURATION VERBOSE command or the SHOW FAST_START FAILOVER command on the primary database.