time specified in the WAIT option. The broker reinstates the database as a standby database of the same type as the former standby database of the new primary database. FSFO can also be used with logical standbys and an FSFO-enabled configuration may have multiple standbys with a mix of physical and logical, but only one standby can be the failover target at any given time. Maximum availability SYNC or FASTSYNC or ASYNC, Maximum performance SYNC or FASTSYNC or primary, only the observers specified in the property can be use in the SET If one of these errors has occurred, follow the guidelines in "Resolving ORA-752 or ORA-600 [3020] During Standby Recovery" in My Oracle Support Note 1265884.1 before proceeding. 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. 12c upgrade, The below commands will help to bring up standby as primary, https://www.linkedin.com/in/hari-prasath-aa65bb19/, https://www.facebook.com/groups/894402327369506/. Failover automation ensures a seamless transition from the primary database to a synchronized standby database in cases of failure, while ensuring database availability by replaying uncommitted in-flight transactions. If fast-start failover is enabled you can still perform a switchover or a manual failover as long as certain conditions are met. Fast-start failover can be used only in a broker configuration and can be configured only through DGMGRL or Cloud Control. Note: If you have just enabled archivelog mode, force an archive log creation ( alter system archive log current) to ensure that at least one archive log exists. 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. After a failover, a bystander will not automatically become the new failover target. Each observer has its own log file. The ObserverOverride configuration property, when set to TRUE, allows an automatic failover to occur when the observer has lost connectivity to the primary, even if the standby has a healthy connection to the primary. Disable fast-start failover using the DGMGRL DISABLE FAST_START FAILOVER command. If clients are already configured to automatically time out and reconnect if they don't get a response from the database, a simple but effective approach is to use a network alias (e.g. 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. 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. 1. Add the primary database and each standby database to the address list. connection, or the database on which you issued the disable fast-start failover A complete failover also attempts to avoid disabling any standby databases that were not the target of the failover, so that they may continue serving as standby databases to the new primary database. SET ObserverConfigFile used to specify a customized observer configuration file. SET MASTEROBSERVER TO allows you to manually change the observer configuration file. Broker will set the primary to use asynchronous log transport by default. The syntax for the optional definition of a broker configuration group is: The group definition section is optional. The "Configuring Authentication" chapter of the Oracle Database Security Guide provides detailed instructions for creating a wallet. In a separate terminal session, verify the configuration. FastStart Failover Ensues: Disaster strikes the primary database and its network connections to both the observer and the target standby database are lost. Determine the number and size of the Online Redo Log files (ORLs). If the observer is stopped abnormally (for example, by typing CTRL/C), restart it and reference the existing fsfo.dat file with the FILE IS qualifier. fast-start failover, you can issue the DGMGRL SHOW FAST_START FAILOVER, When the process is complete, the database will be enabled as a standby database to the new primary database, and Cloud Control displays the Oracle Data Guard Overview page. Standby databases that are disabled during switchover, manual failover, or fast-start failover will not be automatically reinstated. The failover was to a logical 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. The Column Value in the following table is consistent across instances in an Oracle Real Applications Clusters (Oracle RAC) environment. However the target can receive redo from a far sync instance.). failover with the FORCE option on the primary database. We will create 4 SRLs starting with group# 11. If the database is not enabled, you will not be able to perform a failover to this database. Enable Active Data Guard for read-only workloads. If client-side ONS configuration is used, the client-side ONS configuration file must specify the hostname and port of the ONS daemon(s) of the primary database and each standby database. Perform a switchover to a standby database that is not configured as the fast-start failover target, Perform a switchover to the target standby database in a configuration operating in maximum availability mode, unless the standby database is synchronized with the primary database, Perform a switchover to the target standby database in a configuration operating in maximum performance mode, unless the standby database is within the lag limit of the primary database. Switchover Steps. The primary database can be reinstated if it had flashback database enabled. If the agent is not Its primary job is to perform a failover when conditions permit it to do so without violating the data durability constraints set by the DBA. These clients can be configured for Fast Connection Failover (FCF) to automatically connect to a new primary database after a failover. Broker keeps its configuration details in flat file. For more details about managing Redo Apply services using properties, see Managing Log Apply Services. ConfigurationSimpleName. gets enabled and then begins monitoring. For switchovers, understanding all of the factors can simplify the choice of which standby database to consider as your new primary database. Stopping the observer does not disable fast-start failover. 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. REINSTATE REQUIRED is present only after fast-start failover has occurred and shows on both the new primary database and the database undergoing reinstatement. times that the observer retries a failed ping before it initiates a Stopping a Specific Observer When There are Multiple Observers. The targets are referred to as candidate targets. We'll start it interactively for now to verify that everything's working. configuration file, such as START OBSERVING, 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. You can enable fast-start failover from any site while connected to any database in the broker configuration. After the restart, Redo Apply begins applying redo data from the new primary Fast-start failover will not occur unless all instances comprising the Oracle RAC primary database are perceived to have failed. 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. The broker interacts with Oracle Clusterware or Oracle Restart to ensure that the appropriate database services are active and that the appropriate FAN events are published after a role change. To avoid problems due to timing variations, values less than 60 minutes are not recommended and values of 30 or less virtually guarantee Flashback Database failure. Stores the observer runtime data file and observer configuration file in Oracle Database PL/SQL Packages and Types Reference, Stop the observer from any computer system in the broker configuration, as described in, Start the observer on the new computer system, as described in Step 8 of, Enable fast-start failover using the DGMGRL, Shut down the primary database and the target standby database using either DGMGRL, Oracle Database Global Data Services Concepts and Administration Guide, Oracle Real Application Clusters Administration and Deployment Guide, Configure the connect descriptor for connect-time failover. For example, if a physical standby database was in the APPLY-OFF state, it will remain in the APPLY-OFF state. Broker is a Data Guard management utility that maintains state information about a primary and its standby databases. You must use the Oracle wallet to store the credentials for all broker configurations to be managed. database that has the least amount of unapplied redo (smallest apply lag). The example below takes advantage of the 11g RMAN Active Database Duplication feature. They must be re-created from a copy of the new primary database. 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. Data Guard Configuration Details:-. It has two parts in the following order: Configuration declaration this section is mandatory. Then the STOP OBSERVER command can be issued successfully on the former master observer. If a group name is not specified, then SHOW OBSERVERS alone is also a valid command. A broker configuration can belong to multiple groups. this script is run before the fast-start failover is initiated. Data Guard Broker Failover - DBA Genesis Support 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. DG Broker_GottdesKrieges-CSDN Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. When the primary database and the target standby database regain network connectivity, the broker will disable fast-start failover for the entire broker configuration. environment variable to specify the default location for client-side broker files. Prerequisites for Enabling Fast-Start Failover provides complete information about all of the fast-start failover and reinstatement requirements. Then set the configuration protection mode to maximum availability. The guide attempts to be operating system agnostic; however, some examples may contain platform specific elements such as path and file naming conventions. (Note that the target standby cannot be a far-sync instance. Set the ObserverPingInterval and The VALIDATE FAST_START FAILOVER command parses the callout After the former primary database has been repaired, the observer reestablishes its connection to that database and reinstates it as a new standby database. Issue the following commands on Primary database and Standby database to find out: The time interval specified by the FastStartFailoverThreshold property is ignored if the master observer detects that a user-configurable condition has occurred or if a fast-start failover has been requested by the DBMS_DG.INITIATE_FS_FAILOVER function. Fast-start failover is faster when you take steps to optimize recovery so that the application of redo data to the standby database is kept up to date with the primary database's rate of redo application. The minimum value is 100 milliseconds. See Enabling Fast-Start Failover for more information. Any unsent redo data residing on the far sync instance is transmitted to the target physical standby prior to converting the physical standby into a primary database. Switching over to a logical standby database results in the snapshot and physical standby databases in the broker configuration being disabled by the broker, making these databases no longer viable as standby databases. Note that this does not guarantee no data will be lost. However, you do have the option of specifying a name and location for the observer configuration file. You have done a failover to your Standby database so it becomes the new Primary. fsfocallout.ora. Therefore, the detection time can be reduced to nearly Oracle 19c-Step by Step Manual Data Guard Failover When performing a switchover in a configuration whose standby databases are lower detection times for primary database failures, you must These are the actions the broker performs after you start a complete failover. Switchover and Failover Operations - Oracle Help Center document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. How to reinstate the old Primary as a Standby after Failover in #Oracle In 10g, a single wallet can be used for multiple observers, but they must all use the same SYS password. Overall Steps:-. db1_a: Alias to connect to the dynamic Data Guard service on database "a", db1_b: Alias to connect to the dynamic Data Guard service on database "b", db1_a_static: Alias to connect to the static Data Guard service on database "a", db1_b_static: Alias to connect to the static Data Guard service on database "b". To see Manual Switch Over Manual SwitchOver in Oracle To see Manual Fail Over Manual Failover in Data Guard With Oracle Data Guard [] The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. Create a script to automate FSFO failover initiation and use it as your standard method for standby flips. They cannot be reinstated. To reenable broker management of these databases, you must reinstate or re-create the databases using one of the following procedures: If a database can be reinstated, the database will show the following status: Reinstate the database using the DGMGRL REINSTATE DATABASE command or the reinstate option in Cloud Control, as described in How to Reinstate a Database. Examine the Broker configuration by logging into dgmgrl on the new primary. The same thing happens if a shutdown and startup of either database occurs - the service that is started is the one that matches the role of the database being started. If you cannot tolerate any loss of data, then ensure that the configuration protection mode is set to maximum availability or maximum protection. 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. On the Oracle Data Guard Overview page in Cloud Control, select the standby database that you want to change to the primary role and click Failover. 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. on particular instances based on the service configuration. To perform specified actions before or after a fast-start failover 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. The observer maintains state information in a file. Oracle Corporation recommends that you specify this type of failover. Fast-start failover will not be attempted for the other types of database shutdown (NORMAL, IMMEDIATE, TRANSACTIONAL). Updates the broker configuration file to record the change in roles. automatic failover feature in configurations set up for zero data loss protection at any All database connections associated with the observer, including the initial connection, must use dedicated server connections. On the Oracle Data Guard Overview page, click Database must be reinstated. Oracle 11g Manual Data Guard Part-II - DBAtricksWorld.com Note that primary and standby databases must be licensed for Oracle RAC or Oracle Active Data Guard in order to use Application Continuity. Select name,open_mode,database_role from v$database; Step:2 Cancel the MRP process lose no more than the amount of data (in seconds) specified by the Check the database role,open_mode in standby server. 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 OberverPingRetry property specifies the number of This method will disable fast-start failover on all databases in the broker configuration. What is true about Data Guard setup with fast-start failover? If only a path is specified, the files are commands. FAN events are always published through ONS. If you want to use one Oracle home to start multiple observers, with each observer monitoring a different fast-start failover configuration, use the FILE qualifier to specify a unique observer configuration file location for each configuration to be monitored. list of the observers that can become the master observer when that (See Disabling Fast-Start Failover for important considerations when using the FORCE option.). performance protection mode with fast-start failover.