data guard failover steps

Fast-Start Failover in Oracle 11g Data Guard. The rest of this section provides examples of using DGMGRL SHOW commands to display fast-start failover information and includes sections describing the following views: The DGMGRL SHOW FAST-START FAILOVER command displays all the fast-start failover related information. This allows Data Guard to remain functional during maintenance periods when the application listeners are down. command is submitted successfully, the command-line prompt on the Else, broker restarts the new The value specified for either of these properties should allow the master observer to connect to any instance of an Oracle RAC database. It is very much useful, when the organization has multiple standby sites. This action may result in two databases in the configuration simultaneously assuming the primary database role should fast-start failover occur. We want the observer to be able to automatically reinstate the former primary as a standby after our failover tests, so before each test, make sure that Flashback Database has at least 30 minutes of history. observer as a foreground process. 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. crash, data in this file can be used to restart the observer to the The broker first converts the original primary database to run in the standby role. Verify the configuration from both hosts. (Yes, bystanders need Flashback Database too). If these parameters are modified outside of Broker, it raises a warning. command on the observer computer: The observer is a continuously executing process that is 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. Any database that was disabled while multiple role changes were performed cannot be reinstated. must create a .suc and .err file in the FastStart Failover Ensues: Disaster strikes the primary database and its network connections to both the observer and the target standby database are lost. When DGMGRL starts, if the DG_ADMIN lower detection times for primary database failures. A failover is a role transition in which one of the standby databases is transitioned to the primary role after the primary database (all instances in the case of an Oracle RAC database) fails or has become unreachable. They can all be done at the same time in a single bounce. pre-callout configuration script and post-callout configuration script. directory by this environment variable does not exist, or the $DG_ADMIN STOP OBSERVING [cfg_group_name] stops LOCAL observers running on this host (where this DGMGRL is running) for all broker configurations in a specified group. Remember to check Flashback Database history before aborting the primary. North_Sales is in the primary role. See Enabling Fast-Start Failover for more information. Without the credentials, Broker will complete the role transition, but will leave the databases in need of a manual restart. commands. SQL> Select Database_role from v$Database; There are many examples, and Ritesh Chhajer offers this example of doing a Data Guard switchover using dgmgrl: 1. In such a case, no attempt is made to transmit any unsent redo from the cascader to the terminal standby. Steps to Create a Physical Standby Databa se 3 -3 Preparing the Primary Database 3 -4 FORCE LOGGING . The old Primary must have been running in flashback mode before the failover. Provides an automatic failover environment Only the master observer can coordinate fast-start failover with Data Guard broker. The current primary database must have its LogXptMode property set accordingly and must have standby redo logs configured. 2. Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A Complete Hands On Lab Practice To Manage A Data Guard . The FastStartFailoverTarget configuration property on the primary unless the new property value contains the current fast-start failover target. Regardless of the method you choose, the broker coordinates the role transition on all databases in the configuration. Immediately after issuing command in step 2, shut down and restart the standby instance STAN: Although the default value of 30 seconds is typically adequate for detecting outages and failures on most configurations, you can adjust failover sensitivity with this property to decrease the probability of false failovers in a temporarily unstable environment. Then set the configuration protection mode to maximum availability. broker opens all the PDBs on the new primary database and on the target standby Verify the primary database instance is open. Starting the Observer Using Cloud Control. When the primary database and the target standby database regain network connectivity, the broker will disable fast-start failover for the entire broker configuration. The broker allows the switchover to proceed as long as there are no errors for the primary database and the standby database that you selected to participate in the switchover operation. You can find detailed information about all observers, including master observers and backup observers, in the V$FS_FAILOVER_OBSERVERS view. All Data Guard environments should enable force logging at the database level in order to guard against nologging tablespaces from being added. This is particularly useful when registering with multiple listeners where the parameter value would otherwise exceed the 255 character limit. To stop a specific observer when there are multiple registered observers running, issue the following command: You can log into DGMGRL from any machine to stop an observer. You will have to reinstate or re-create (see Reenabling Disabled Databases After a Role Change) the standby databases after failover has completed. The targets are referred to as candidate targets. In the media recovery phase, Flashback Database applies redo to bring the database up to the standby_became_primary_scn. Fast-start failover can be used only in a broker configuration and can be configured only through DGMGRL or Cloud Control. Verifies that the target standby database is enabled. See the START OBSERVER If you will be using RMAN to create the standby database, it also needs a static service to restart the database being created. To help you select an appropriate switchover or failover target, use the following DGMGRL commands which perform checks on the database to determine its readiness to complete a role change. configuration file, such as START OBSERVING, The new primary database starts transmitting redo data to the new standby database. After step 1 finishes, Switch the original physical standby db STAN to primary role; A normal shutdown prevents a fast-start failover until the primary database and standby database are connected and communicating again. During failover, bystanders "follow" the primary by default, flashing back and reapplying redo from the new primary as necessary. 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. For any work, queries and help. If errors occur during the disable operation, the broker returns an error message and stops the disable operation. See Installing and Starting the Observer. The name of the callout configuration scripts is specified in On primary database NORTH, execute the following: On standby database SOUTH, execute the following: Services that are to be active while the database is in the physical standby role must also be created and started on the current primary database regardless of whether the service will be started on that database or not. Additionally, the new master observer is identified in the output shown for the SHOW FAST_START FAILOVER and SHOW OBSERVER commands. If you perform a manual failover when fast-start failover is enabled: The failover can only be performed to the current target standby database. Open another prompt and connect to SQLPLUS: The command fails if the file does not exist. If both of those observers are unavailable, the observers 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. A far sync instance or Zero Data Loss Recovery Appliance is not a database and therefore cannot be the target of a role transition. Immediate Failovers in Configurations Using Cascaded Standbys. Because fast-start failover was not disabled on the target standby database, the observer may still attempt a fast-start failover to the target standby database should conditions warrant a failover. 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. 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 . If an application has called this function and it has received a status of SUCCESS, then the master observer attempts a fast-start failover. the current working directory, Uses standard output for displaying the observer logs. The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. is guaranteed to lose no more than the amount of We suggest you try the following to help find what youre looking for: This document will guide you through configuringOracle Data GuardFast-Start Failover (FSFO) using a physical standby database. 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. These are some points to consider before you begin a switchover. required permissions, DGMGRL reports an error. The SHOW CONFIGURATION command will show you which databases can be reinstated and which databases must be re-created. $DG_ADMIN directory. directory. To stop an observer currently designated as the master observer, first issue the SET MASTEROBSERVER command to designate a different observer as master observer. This is the recommended method for disabling fast-start failover. ConfigurationSimpleName. This section describes how to stay on top of your FSFO environments. alter database set standby database to maximize availability; If you don't already have a standby database, use your favorite method to create one. 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. If possible, confirm that fast-start failover has not START OBSERVING [cfg_group_name] starts a new observer for each broker configuration in the specified group. The default name for This guide uses the naming convention of appending an underscore followed by a letter to the db_name to create the db_unique_name. There's a big difference between a system that's FSFO enabled and one that's FSFO ready. To enable fast-start failover with DGMGRL, issue the ENABLE FAST_START FAILOVER command while connected to any database in the broker configuration, including on the observer computer. post-callout script, and pre-callout success file for the broker The observer immediately initiates a fast-start failover, as long as the failover target database is in a valid fast-start failover state ("observed" and either "synchronized" or "within lag") to accept a failover. This list describes restrictions when fast-start failover is enabled. client-side broker files, the specified values are used. Determine the number and size of the Online Redo Log files (ORLs). This directory is created when you run the may allow the primary database to continue redo generation after guaranteed to lose no data. Make sure the last redo data transmitted from the Primary database was applied on the standby database. Application Continuity is supported for Oracle Data Guard switchovers to physical standby databases. value of the FastStartFailoverThreshold property. FAN events are always published through ONS. ORACLE instance shut down. observer, whether it is currently connected to the primary and target standby databases, You must multiple, inexpensive servers is the basis for the failover and other fault-tolerance features that RAC provides. lag is less than or equal to the value specified by the However, you can change the name or the location of the file if you start the observer using the DGMGRL START OBSERVER command and include the FILE IS qualifier. Broker will set the primary to use asynchronous log transport by default. beneficios del jugo de chayote crudo, daniel mccoy obituary, why did coleman stop making catalytic heaters,