You can also specify a list of ORA- errors that will initiate FSFO failover. See Disabling Fast-Start Failover. Oracle Data Guard helps you change the role of databases between primary and standby using either a switchover or failover operation. If the value is zero, the standby must Oracle Database 10g databases running versions prior to 10.2.0.4 will remain in a stalled state until aborted or signaled to remain the primary by the observer once connectivity has been restored. On the Data Guard Failover Confirmation page, specify the type of failover that you want to perform: Complete: All available redo is applied on the standby database. Create a script to automate FSFO failover initiation and use it as your standard method for standby flips. Updates the broker configuration file to record the change in roles. Displays only on a logical standby database that has not yet completed loading a copy of the primary database's data dictionary. If both of those observers are unavailable, the observers 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. 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. Initiate reinstatement by mounting the database. This is In an immediate failover, it is also possible to failover to a standby database (terminal standby) that gets redo from another standby database (cascader). Run the RMAN utility and connect to the target (primary) and auxiliary (new standby). 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. For example, if all your physical standbys are also unavailable, then failing over to a logical standby is your only choice. (For example, if the DBMS_LOGSTDBY.SKIP procedure was used to specify which database operations done on the primary database will not be applied to the logical standby database.). the ObserverPingRetry and ObserverPingInterval properties to achieve Note: You can also use TNS aliases defined in the tnsnames.ora file when setting the local_listener parameter. command START OBSERVER IN BACKGROUND. command for more information about starting the If automatic reinstatement fails, the broker will log errors and the former primary database will remain in the mounted state. Note that the database will not open at this point. This section will help you get started with creating a wrapper script to automatically start and restart the FSFO observer. Regards, Narottam Tagged: dataguard dba rac Welcome! Oracle Real Application Clusters Administration and Deployment Guide for information about Application Continuity, The broker simplifies switchovers and failovers by allowing you to invoke them using a single key click in Oracle Enterprise Manager Cloud Control (Cloud Control) or a single command in the DGMGRL command-line interface (referred to in this documentation as, Ensure that the standby database you choose to be the target of fast-start failover has its, Oracle Data Guard Concepts and Administration. The SHOW CONFIGURATION command will show you which databases can be reinstated and which databases must be re-created. Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. Once Flashback Database has succeeded, the observer will convert the database to a standby, bounce it, and begin apply services. failure on the primary database. Steps for FAILOVER the Dataguard environment How to reinstate the old Primary as a Standby after Failover in #Oracle Use the oraenv script provided by Oracle. Because the broker performs the failover after converting the snapshot standby database to a physical standby database, 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. See Reenabling Disabled Databases After a Role Change. For example, if the old standby was a physical or snapshot standby, then the old primary must be re-created as a physical standby. If you have not used the SET ObserverConfigFile command after starting the current DGMGRL client, then the result will always be: ObserverConfigFile=observer.ora. Reconnect within the time specified by the FastStartFailoverThreshold property. Fast-start failover will not be attempted for the other types of database shutdown (NORMAL, IMMEDIATE, TRANSACTIONAL). 2) Switchover/Failover option is disabled on Enterprise Manager.What are the steps to enable it so that I can do Switchover/Failover operation using OEM. db_domain . prolonged stall, either the observer or target standby database Enabling fast-start failover in a configuration operating in maximum performance mode provides better overall performance on the primary database because redo data is sent asynchronously to the target standby database. the location of the observer log file, and the location of the observer runtime data If necessary, you can shut down the primary or target standby database in a fast-start failover environment. Remote login is required, along with a password file, to allow the databases in a Data Guard configuration to connect to each other. If a single-instance primary database (either Oracle RAC or non-Oracle RAC), or if all instances of an Oracle RAC primary database fail, the observer attempts a fast-start failover. 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. You can also switch the master observer hosts for a group of configurations to one specific host. How to Re-create and Reenable a Disabled Database. After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. configuration property specifies how frequently the observer SQL> Select Database_role from v$Database; Group definition this section is optional. In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. Only the master observer can coordinate fast-start failover with Data Guard broker. How To Use Local Data Processing and Oracle Data Guard for Source Displays if the standby database's redo applied point does not lag the primary database's redo generation point by more than the number of seconds specified by the FastStartFailoverLagLimit configuration property and the configuration is operating in maximum performance mode. In this mode you will need to consider how much data loss is acceptable in terms of seconds and set the FastStartFailoverLagLimit configuration property accordingly. The Data Guard broker and the secondary database both run the observer and observe the primary database for downtime. This property cannot be used to prevent the primary database from shutting down if a fast-start failover occurred because a user configuration condition was detected or was requested by an application by calling the DBMS_DG.INITIATE_FS_FAILOVER function. To stop the observer, see Stopping the Observer. You can query the V$DATABASE view to verify that the observer is started and the configuration is ready for fast-start failover. The default value is 30 seconds and the lowest possible value is 5 seconds. FAN server-side callouts can be configured on the database tier. 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). You must You cannot create the standby DB system in a different AD from the primary DB system. By default, both files are stored in $ORACLE_HOME/dbs. Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. A switchover is a role reversal between the primary database and one of its standby databases. The string "NONAME" cannot be used as an observer name. The platform provides comprehensive services such as maintaining and monitoring databases to help the oracle databases in surviving during data corruption. the service configuration. connectivity with target standby. You can issue a 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. In a separate terminal session, verify the configuration. To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE. This list describes conditions in which the broker cannot automatically reinstate the former primary database. The If fast-start failover is disabled, then manual failover may still be possible. 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. It could optionally also be removed from the primary database if there is no intention to ever run this service on the current primary database. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. by the current operating system user who is running DGMGRL The subdirectories Using the db_unique_name of each database as the Oracle Net alias is simple and intuitive. When you configure data guard using OCI console, the default mode is set to maxprotection. Displays when the target standby database does not have all of the primary database redo data and the configuration is operating in maximum availability mode. 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. Look for the desired data in the RAM. The price for this guarantee is increased commit latency ( log file sync waits). A failover may or may not result in data loss depending on the protection mode in effect at the time of the failover. Log in as a test user and make some changes that won't impact other parts of the system. When using DGMGRL, you need to issue the SWITCHOVER command, specifying the name of the standby database that you want to change into the primary role. DG_ADMIN environment variable is not set, the files are stored in It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. In this case, the observer cannot perform a fast-start failover even if conditions warrant a failover. Fast-Start Failover in Data Guard Environments on Oracle Cloud Choosing a Target Standby Database for Switchover and Choosing a Target Standby Database for Failover provide guidelines to help you choose a target standby database. return until you issue the STOP OBSERVER command STAN is now transitioned to the primary database role.Now your PHYSICAL STANDBY Database has become PRIMARY. 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. Ideally the primary, standby, and observer will be in geographically separate areas. The drain_timeout is specified in the SRVCTL The v$database view has has columns specifically for monitoring FSFO status. If block change tracking is enabled on the primary, and the target This list describes restrictions when fast-start failover is enabled. guaranteed to lose no data. You can register up to four observers to monitor a single Data Guard broker configuration. failover configuration file, this script is run. commands. On Windows, the directory specified by the DG_ADMIN 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. These To start an observer as a background process, use the DGMGRL DG BrokerDG BrokerData Guard BrokerOracleDGRMAN Duplicate . The minimum value is 100 milliseconds. observers for a single Data Guard configuration. Oracle Database 11g adds the ObserverConnectIdentifier database property to the Broker configuration, allowing you to specify a connect identifier for the observer to use for monitoring the primary and failover target. No two observers on the same Data Guard Broker configuration can have the same name. The most common problems are mismatched Data Guard protection modes and LogXptMode properties and forgetting to enable Flashback Database on the primary or standby. Switchover and Manual Failover for more information about switchovers and manual failovers, respectively. The following sections provide information about managing observers: How the Observer Maintains Fast-Start Failover Configuration Information, Patching an Environment When the Observer Is Running and Fast-start Failover Is Enabled. 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. The broker reinstates a failed primary database as a standby database of the same type (physical or logical standby database) as the old standby database. Now let's test switchover in the other direction. The FastStartFailoverLagLimit configuration property is only used by the broker when enabling fast-start failover for configurations operating in maximum performance mode. The DB_ROLE_CHANGE event will fire whenever a database is opened for the first time after a role transition. 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 . This property is measured in If only a file name is Flashback Database is a continuous data protection (CDP) solution integrated with the Oracle Database. issue commands and interact with the broker configuration. After step 1 finishes, Switch the original physical standby db STAN to primary role; The guide attempts to be operating system agnostic; however, some examples may contain platform specific elements such as path and file naming conventions. 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. It provides a way to quickly restore a database to a previous point in time or SCN using on-disk data structures called flashback logs. If the service has been configured to start automatically (-policy AUTOMATIC), then the service will automatically start only after a database role change. SHOW OBSERVER command to confirm that the switch took place. mode when the fast-start failover target is a logical or physical standby database that Refer to the appropriate Oracle RAC or Oracle Restart documentation for further information. POTENTIAL DATA LOSS: Fast-start failover is enabled with some data loss. RAM). These scripts must be in the same directory as the For Fast Connection Failover (FCF) to occur, a client must be able to locate the new primary database after a failover. The following paragraphs describe the supported availability modes. 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. primary database must have network connectivity. It's generally a good idea to store the state file in a directory associated with the database to avoid locking issues when running multiple observers on the same host. If fast-start failover is already enabled, the The logs also contain other details about the actions that will be performed in case of a failover. Fast-Start Failover allows Data Guard to automatically failover to a previously chosen standby database without requiring manual intervention to invoke the failover. ASYNC. created under this directory by DGMGRL will also have the same permissions. lag is less than or equal to the value specified by the FB Group:https://www.facebook.com/groups/894402327369506/ FSFO configurations in Maximum Performance mode may limit potential data loss by specifying the maximum allowable age of transactions that are lost during a failover. Starting with 10.2.0.4 (including all versions of 11g and later), Oracle provides the FastStartFailoverPmyShutdown Broker property that allows you to specify what the primary should do if it is still in a stalled state when the FSFO threshold timeout has elapsed. crash, data in this file can be used to restart the observer to the In addition, the primary database will shut down if it perceives a loss of connectivity for a period longer than FastStartFailoverThreshold seconds, if the FastStartFailoverPmyShutdown configuration property is set to TRUE. data (in seconds) specified by the ZERO DATA LOSS: Fast-start failover is enabled with zero data loss. 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. Any broker configuration name that is referred to must exist in the configuration declaration section. Required fields are marked *. The time interval starts when the observer first loses its connection to the primary database. 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. When the conditions for fast-start failover are met, the Broker adds messages to the observer log and broker log indicating that fast-start failover would have been initiated. cannot use a different name for this file. For more details about managing redo transport services using database properties, see Managing Redo Transport Services. PeopleSoft can be configured for Active Data Guard. The ObserverReconnect configuration property specifies how often the observer establishes a new connection to the primary database. If fast-start failover is If the primary or target standby databases lose connections to all backup observers, then the broker does not try to nominate a backup observer as the new master observer, and the broker reports that the configuration is not observed. Note: Many of the Broker database properties correspond to database spfile parameters. 2. FSFO builds upon a number of other Oracle technologies and features such as Data Guard, Flashback Database, and Data Guard Broker. Relationship Between Primary, Target Standby, and Observer During Fast-start Failover. Were sorry. Oracle Database 10g allows a different password file to be used as long as the SYS passwords are the same on the primary and standby. Slightly less critical than making sure you've got a good primary is making sure the failed primary can be automatically reinstated. In a manual failover, you convert a standby database to a primary database because the original primary database failed and there is no possibility of recovering the primary database in a timely manner. 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. fsfocallout.ora. For example: In the following example, assume the network between the primary database and the observer has failed. The subcommands for this verb include start, stop, setMaster, show, and delete_alternate_observer. Once fast-start failover is enabled, the broker will ensure that fast-start failover 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. The information in this guide is based on practical experience gained from deploying FSFO in a global corporate production environment. second. fast-start failover to the target standby database if conditions warrant a failover. After a failover, the broker publishes Fast Application Notification (FAN) events. OBSERVE-ONLY: Fast-start failover is enabled in observe-only mode. ObserverConnectIdentifier allows you to specify different connect identifiers for the observer to use. receives redo data from a far sync instance. If you perform a manual failover when fast-start failover is enabled: The failover can only be performed to the current target standby database. Verifies that the primary and the target standby databases are in the following states: The primary database is enabled and is in the TRANSPORT-ON state. The observer persistently maintains information about the fast-start failover configuration in a binary file created in the working directory where you started the observer. Prerequisites for Enabling Fast-Start Failover provides complete information about all of the fast-start failover and reinstatement requirements. 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. Cloud Control will start the observer. Standby databases that are disabled during switchover, manual failover, or fast-start failover will not be automatically reinstated. The following is an example of querying the V$FS_FAILOVER_STATS view: Disabling fast-start failover prevents the observer from initiating a failover to the target standby database. If the new primary database was a primary database in the past, and had block However, if the standby has had contact from the primary within the period of time specified by the FastStartFailoverThreshold property, the standby prevents the failover attempt. The broker never automatically reinstates the former primary database if a fast-start failover was initiated because a user configuration condition was detected or was requested by an application calling the DBMS_DG.INITIATE_FS_FAILOVER function.