under the $DG_ADMIN directory. See Disabling Fast-Start Failover. Verify dmon process is running and broker parameters viz. Databases that have been disabled after a role transition are not removed from the broker configuration, but they are no longer managed by the broker. Oracle Database PL/SQL Packages and Types Reference for more information about the DBMS_DG package. Select name,open_mode,database_role from v$database; Step:2 Cancel the MRP process If the primary database is an Oracle Real Application Clusters (Oracle RAC) database, the master observer will attempt to connect to one of the remaining primary instances. If the value is zero, the standby must Disabling fast-start failover does not stop the observer. For Active Oracle Data Guard, it will fail to open up a connection unless its in read-only mode. Even if you have successfully connected to a database server in the broker configuration using the CONNECT command, this command ignores the existing connection and uses the credentials stored in Oracle wallet. Immediately after issuing command in step 2, shut down and restart the standby instance STAN: Chapter 9 of the Data Guard Broker documentation (10g and 11g) contains a description of each property. Which three are prerequisites for enabling fast-start failover? Whenever possible, you should switch over to a physical standby database: If the switchover transitions a physical standby database to the primary role, then: The original primary database will be switched to a physical standby role. Once fast-start failover is enabled, the broker will ensure that fast-start failover FSFO is a feature of Broker which records information about the failover target, how long to wait after a failure before triggering a failover, and other FSFO specific properties. When running the START To failover, connect to the standby database and use the DGMGRL FAILOVER TO db-unique-name command. It will not be allowed to open in any event if fast-start failover is enabled. Otherwise, the DUPLICATE TARGET DATABASE command will fail with "RMAN-20208: UNTIL CHANGE is before RESETLOGS change". The FastStartFailoverThreshold time interval starts when the observer first detects there might be a failure with the primary database. SHOW ObserverConfigFile used to check the runtime property ObserverConfigFile. Failover:- 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. Use Cloud Control or DGMGRL to perform either a complete (recommended) or an immediate failover. distance. For example, perform full level 0 backups weekly and incremental level 1 backups daily. You must specify it every time you start a new DGMGRL client. 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. How to Failover to a Standby Database Manually and Rebuild Data Guard Depending on the failover and the types of standby databases involved, some of the databases may need to be reinstated or re-created. On the new primary database STAN, perform a SWITCH LOGFILE to start sending redo data to the standby database PRIM. On Windows, the directory specified by the DG_ADMIN During failover, bystanders "follow" the primary by default, flashing back and reapplying redo from the new primary as necessary. 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. specified, the file is stored in an appropriate directory under the broker's After setting local_listener, register the database with the listener and verify the services have been registered. change tracking enabled, broker enables block change tracking on the new If fast-start failover is Each observer is identified by a name that you supply when you issue the START OBSERVER command. ObserverPingRetry properties before 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. In cases where Unless action is taken to change the failover target to one of the bystanders, the new primary will be without a failover target until the former primary is reinstated as a standby. The following example shows you how to set up more than one service on a database and how using the broker ensures that the correct service starts on the correct database. Another good test is to simulate network failures that leave the primary up, but isolated from the failover target standby and the observer. To verify this change, again query the Database_role column of V$DATABASE. This page will not allow you to alter the protection mode. Verify the configuration from both hosts. configuration named ConfigurationSimpleName. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. In maximum protection mode, set the LogXptMode database property to SYNC (note that in maximum protection mode, a far sync instance cannot be used to ship redo to a standby). Theoretically, this method can be used when a data guard failover occurred between the primary and standby database, but not a switchover. If the Oracle Data Guard configuration is operating in maximum protection mode, the broker does not allow a switchover to occur to a logical standby database. Is possible if the target standby database displays SYNCHRONIZED and the FS_FAILOVER_OBSERVER_PRESENT column displays YES. Fast-start failover will not be attempted for the other types of database shutdown (NORMAL, IMMEDIATE, TRANSACTIONAL). 12c Dataguard, In The standby VM (myVM2) has the Oracle software installed only. Be aware that if you issue the following manual commands on either of those databases, then both the SALESRO and SALESRW services would be started on the databases regardless of what you may have earlier specified with the SRVCTL -role qualifier. Stores files related to the observer and callout configuration. A running observer will follow the primary automatically after a role transition, but a newly (re)started observer won't start if the initial connection is to a down database or one with an out of date or corrupted Broker config file. The FS_FAILOVER_OBSERVER_PRESENT column displays YES for the target standby database. Only the master observer can coordinate fast-start failover with Data Guard broker. environment that is guaranteed to either lose no data (when the Oracle Data Guard is a solution provider to businesses by offering data protection and its disaster recovery along with its high availability. Switches roles between the primary and standby databases. Instead, when broker notifies the Oracle Maximum Availability mode uses synchronous redo transfer and FSFO imposes the additional requirement that the redo is recorded in the standby redo log (SRL) of the target standby (AFFIRM option of log_archive_dest_ n). Alternatively, if you intend to switch back to the original primary relatively soon, then you may re-enable the disabled standby databases after the switch back. MASTEROBSERHOST TO command. These are the actions the broker performs after you start a complete failover. Use the wrapper script to start the observer process when the observer host boots or to restart it if it dies. If the primary database has multiple standby databases, then you can specify multiple fast-start failover targets, using the FastStartFailoverTarget property. command for more information about starting the If the FastStartFailoverPmyShutdown configuration property is set to TRUE, the primary database will shut down after FastStartFailoverThreshold seconds has elapsed if redo generation has been stalled and the primary database is unable to reestablish connectivity with either the observer or target standby database. Reinstatement will have to be accomplished by other means (manual or scripted Broker commands). Such preparation includes: Ensuring that standby redo log files are configured on the primary database. 1. It is then started and stopped on the primary database. (Note that the target standby cannot be a far-sync instance. The database cannot provide fast-start failover status information. ObserverPingRetry configuration properties. For instance, you could log into the system running observer1 to stop observer2. If this operation is successful, a zero data loss failover may be possible even if the primary database is not in a zero data loss protection mode. fast-start failover when: A network outage isolates the primary database from the observer and the target standby database before conditions exist that warrant a failover. They must be re-created from a copy of the new primary database. You can also specify a list of ORA- errors that will initiate FSFO failover. The name of the callout configuration file is fsfocallout.ora. The broker allows an immediate failover to proceed even if there are errors present on the standby database that you selected to participate in the failover. 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. This configuration property establishes an acceptable limit, in seconds, that the standby is allowed to fall behind the primary in terms of redo applied, beyond which a fast-start failover will not be allowed. collections and databases Set up replica sets and automatic failover in MongoDB Use sharding to scale horizontally, and learn how . To do this, use the SET ObserverConfigFile and SHOW ObserverConfigFile commands. This file is stored in the Steps for FAILOVER the Dataguard environment 1. How To Use Local Data Processing and Oracle Data Guard for Source The word manual is used to contrast this type of failover with a fast-start failover (described in Fast-Start Failover). If the configured data loss guarantee cannot be upheld, select name,open_mode,database_role from v$database; Note: The only exception to this is failovers to snapshot standby databases. When you run commands that need access to the observer Oracle Data Guard provides the ability to create and maintain Standby databases at one or more sites These protect Oracle databases from database and server failures as well as site disasters Failover to one of the alternate sites can be set to happen automatically (fast-start failover) or manually if the primary database is not usable Disabling fast-start failover without the FORCE option can succeed only if the database on which the command is issued has a network connection with the primary database and if the primary database and target standby database have a network connection. Specifying Preferred Observers Based on Current Primary. 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. To get started, all you'll need is Oracle Database Enterprise Edition Release 10.2 or later, a database, and three hosts: two for the databases and a small host for the FSFO observer. Fast-start failover quickly and reliably fails over the target standby database to the primary database role, without requiring you to perform any manual steps to invoke the failover. Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. Then, on the Failover Confirmation page, click Yes to invoke the default Complete failover option. Flashing back a database occurs in two stages: For FSFO environments, set db_flashback_retention_target = 60 or higher to provide sufficient Flashback Database history for automatic standby reinstatement. The OberverPingRetry property specifies the number of If the broker performs a switchover or failover, then it starts the service SALESRW or SALESRO based on the current role of the database. If block change tracking is enabled on the primary, and the target 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. Reconnect within the time specified by the FastStartFailoverThreshold property. Data Guard Switchover/failover to standby The standby database will be activated to serve as the primary database at some point in its life cycle. The broker selects a target based on the order in which they are specified on the FaststartFailoverTarget property. fast-start failover. If you performed a failover or switchover that requires you to re-create the failed primary database or standby databases that were disabled during the role transition, then follow the procedures in the Oracle Data Guard Concepts and Administration chapter, "Creating a Physical Standby Database" and also the Oracle Data Guard Concepts and Administration chapter, "Creating a Logical Standby Database.". In this example, the original primary data is called PRIM and the original standby database is called STAN. To stop the observer when fast-start failover is enabled, the primary database and target standby database must be connected and communicating with each other. Do this prior to every failover test. If there is another standby database that is available for failover, you can perform a manual failover to that standby database after you first disable fast-start failover using the FORCE option on that standby database. The following sections describe how to reinstate or reenable a database. PeopleSoft can be configured for Active Data Guard. Steps for Data guard Switch-over and Switchback in Oracle - Doyensys If you initiated a complete failover and it fails, you might need to use immediate failover. Complete Failovers in Configurations Using Far Sync Instances. Starting with 11 is purely cosmetic - it allows new ORL groups to be added later while keeping their group# in the same sequence as the existing ORLs. The default value is 30 seconds and the lowest possible value is 5 seconds. through these services to exit or for the specified wait time You can manually stop a specific observer or all observers. 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. Install the DGMGRL command-line interface on the observer computer as described in Oracle Data Guard Installation. However, there may be situations in which you must disable fast-start failover when A number of prerequisites must be met on the primary in order to use Fast-Start Failover. Oracle 11g Physical standby data Guard Failover steps - Data Guard Part The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. For more information, see START OBSERVER IN BACKGROUND. In the following example, a service named sales is configured to be active in the PHYSICAL_STANDBY role on the primary database NORTH. Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). usually within three seconds if fast-start failover is enabled. These scripts must be in the same directory as the A database in the primary role will not open until it has verified with the observer that it is still the primary. The behavior of the broker if the master observer fails depends on whether the broker configuration has one observer or multiple observers. Examples of starting observers using DGMGRL are included in Scenario 6: Enabling Fast-Start Failover and Starting the Observer. The list is empty by default. Once the Oracle instance is transitioned into primary database status in either switchover or failover, the life of the database as the standby ends and its service as the primary database . SQL>select sequence#, applied from v$archived_log; about starting the observer as a background Now your old standby database is become primary database, it is highly recommended to consider immediate full backup of primary database. However, failover is attempted if the ObserverOverride configuration property is set to TRUE. A failed ping is a ping to (If there are other conditions, unique to an application, that would warrant a fast-start failover then the application can be set up to call the DBMS_DG.INITIATE_FS_FAILOVER function and start a fast-start failover immediately should any of those conditions occur. the observer configuration file is observer.ora. Use the VALIDATE STATIC CONNECT IDENTIFIER command to ensure the static services have been configured correctly. Otherwise, they must be re-created from a copy of the new primary database. Since a fast-start failover (automatic failover) could become a false failover when the observer or the standby database cannot connect to the primary database within a specific time, which may cost the database to lose some transactions followed by reinstating or recreating the standby database (the former primary database). If automatic reinstatement fails, the broker will log errors and the former primary database will remain in the mounted state. RMAN also copies the spfile and password files and you can change the values for individual parameters. The original primary database will be restarted as a part of the switchover operation. the service configuration. Switchover/Failover operation in 2-node RAC and 2-node DATAGUARD Archiver is unable to archive a redo log because the device is full or unavailable. Broker maintains these parameters by issuing ALTER SYSTEM commands as appropriate during role transitions, database startup/shutdown, and other events. PDBs. Startup can fail with "ORA-16647: could not start more than one observer" even when no observer is actually running if the previous observer process terminated without deregistering itself and the new observer isn't using the previous fsfo.dat file. The ObserverPingInterval 1)What are the steps to do Switchover/Failover operation manually in 2-node RAC and 2-node DATAGUARD environment. The redo transport mode used to send redo to the target standby database or the database currently in the primary role. 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. isolated. Issue the following commands on Primary database and Standby database to find out: It's a good idea to have at least two hosts configured to run observers so that one can take over if the other fails. database that has the least amount of unapplied redo (smallest apply lag). 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 . Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. Immediate Failovers in Configurations Using Far Sync Instances. In short, the failover is the deformation of the production (primary) database and activating standby database as the primary. observer computer is returned to you so that you can continue to You can create two callout configuration scripts, a primary database. 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). The procedure for using RMAN to create a standby database is fully explained in Appendix F of Oracle Oracle Data Guard Concepts and Administration document (10g Rel 2 and 11g Rel 1). Enabling Fast-Start Failover describes how to start observers as a part of the step-by-step process to enable fast-start failover. file (fsfo.dat). It will also alert you to databases that have had Flashback Database disabled at some point after FSFO was enabled. redo generation on the primary database will be stalled. In If the switchover occurs to a physical standby database, and the former primary After directory specified by this variable does not exist, or the directory does not have the Choose a value high enough to avoid false disconnects from intermittent network trouble. You must manually re-create the database as a standby database and then reenable it. Oracle FAN with Oracle Data Guard but without using Oracle Grid/ RAC What is true about data guard set up with fast-start failover (FSFO) in Oracle Cloud Infrastructure (OCI)? . You can manage observers through either the Oracle Data Guard Overview pages in Cloud Control or using DGMGRL commands. FSFO builds upon a number of other Oracle technologies and features such as Data Guard, Flashback Database, and Data Guard Broker. It will return PHYSICAL STANDBY, The time interval starts when the observer first loses its connection to the primary database. Provides an automatic failover The configuration status returns the SUCCESS status after the observer reestablishes its connection to the primary database, which then notifies the target standby database. ERROR: Unable to verify the graphical display setup. However, you do have the option of specifying a name and location for the observer configuration file. The broker reinstates the database as a standby database of the same type as the former standby database of the new primary database. Oracle Database 11g observers are incompatible with 10g databases and vice-versa. there is a lost network connection, be aware that the observer may attempt a Another consequence of immediate failover is that all other databases in the configuration are disabled and must be reinstated or re-created before they can serve as standby databases for the new primary database. After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. The steps in this section describe the tasks involved to perform a manual failover. You can disable fast-start failover if necessary, by using the FORCE option. If any errors occur during either conversion, the broker stops the switchover. See the Cloud Control online help for more information. drain_timeout amongst the active services. Improper Oracle Net configuration is a leading cause of reported FSFO issues. The following example displays the contents of the fast-start failover The log file name is specified with the LOGFILE IS option of the START OBSERVER command. If necessary, you can shut down the primary or target standby database in a fast-start failover environment. The connect descriptor can be configured in one of two ways: Oracle Database PL/SQL Language Reference for more information about the DB_ROLE_CHANGE system event. To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE. If you don't already have a Flash Recovery Area (FRA), you will need to create one for Flashback Database. Duplicate configuration names in configuration definitions are not allowed. The group of broker configurations to be managed is declared in the observer configuration file. 1,000,000 block changes on a small set of blocks generates less Flashback Database history than 1,000,000 changes on a larger set of blocks. Any standby database that was disabled by the broker must be reinstated or re-created, as described in Reenabling Disabled Databases After a Role Change, before it can be a standby database for the new primary database. It doesn't consider how much of that redo has been applied. After the fast-start failover completes successfully, the master observer will attempt to reinstate the former primary database as a new standby database when a connection to the former primary database is reestablished, and the FastStartFailoverAutoReinstate configuration property is set to TRUE. Overall commit latency is increased by the round-trip network latency. To stop an observer currently designated as the master observer, first issue the SET MASTEROBSERVER command to designate a different observer as master observer. Broker will validate the configuration, set parameters on both databases, and start managed recovery. If the DG_ADMIN environment variable is not defined, or the environment variable to specify the default location for client-side broker files. A trigger on the DB_ROLE_CHANGE system event can be used to update the naming service and, with the proper client cache TTL settings, clients can connect to the new primary very quickly. set the ObserverPingInterval and