Written by authors well-known for their talent with RAC, Pro Oracle Database 11g RAC on Linux . Fast-Start Failover in Oracle 11g Data Guard. Data Guard Configuration Details:-. Disable fast-start failover using the DGMGRL DISABLE FAST_START FAILOVER command. The primary and target standby must have connectivity for the STOP OBSERVER command to complete successfully. Bystanders are part of the Data Guard configuration, but not part of the FSFO configuration. For more details about managing redo transport services using database properties, see Managing Redo Transport Services. 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. OBSERVER command, if this directory does not have the RMAN will copy the spfile from the primary, so this init.ora file is only needed during the first phase of the duplication. 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. Oracle Data Guard configuration with DGMGRL. 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. Instead, Oracle Clusterware opens PDBs on particular instances based on FAN events are published using Oracle Notification Services (ONS) for all Oracle integrated database clients in Oracle Database 12c and later. file, observer runtime data file (fsfo.dat), fast-start failover callout SHOW OBSERVERS [FOR fg_group_name ] shows information about observers for all configurations in the specified group. there is a lost network connection, be aware that the observer may attempt a Notice that the former primary is now disabled. 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. If the standby database is not enabled for management by the broker, then the failover cannot occur. Administration at the target standby site should be as comprehensive as that at the primary site because the standby database may assume the primary role without prior notice. There are two types of failover operations: Graceful or "no-data-loss" failover and Forced or "minimal-data-loss" failover. During an immediate failover, the broker performs the failover steps described in How the Broker Performs an Immediate Failover Operation. In the event of a 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/. operation: Example 6-1 Fast-start Failover Configuration Stores files related to the observer and callout configuration. Data Guard. 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. by the current operating system user who is running DGMGRL The subdirectories It behaves similarly to START OBSERVING and STOP OBSERVING to operate on all the configurations defined in the observer configuration file. stored in the specified path using the default file names. To stop an observer currently designated as the master observer, first issue the SET MASTEROBSERVER command to designate a different observer as master observer. Being FSFO ready means that all conditions are met for a successful failover, including having a running observer and sufficient redo transmitted to the failover target to meet durability requirements. 3. It's good practice to use separate listeners for application connections and Data Guard connections. Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A Complete Hands On Lab Practice To Manage A Data Guard . You must ensure that the primary database is shut down prior to performing a manual failover. FastStartFailoverLagLimit property. Overall Steps:-. It wouldn't be much of a test if we didn't verify that our durability constraints were being met, so let's make a change on the primary and see if it survives the failover. The new ConfigurationWideServiceName configuration property can be used to simplify setting up this connect identifier. Many customers use Oracle Database deployed on Amazon Elastic Compute Cloud (Amazon EC2) to run their Oracle E-Business Suite applications. Add the wallet location and override to sqlnet.ora. Tailing the alert logs on the primary and standby is a good way to watch Broker in action and get familiar with how it performs various tasks. A switchover is a role reversal between the primary database and one of its standby databases. Oracle Data Guard work on two database roles Primary and Standby. The default group is all the configurations defined in the observer configuration file. To see if your primary has already met a prerequisite, follow the instructions in the Verify section. These clients can be configured for Fast Connection Failover (FCF) to automatically connect to a new primary database after a failover. On Linux/Unix, the directory specified by the DG_ADMIN environment In cases where For example, perform full level 0 backups weekly and incremental level 1 backups daily. observers for a single Data Guard configuration. If the configured data loss guarantee cannot be upheld, Any broker configuration name that is referred to must exist in the configuration declaration section. file also declares broker configurations and defines configuration the service configuration. 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. A failover may or may not result in data loss depending on the protection mode in effect at the time of the failover. 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. Log in as a test user and make some changes that won't impact other parts of the system. A manual failover is already in progress. This can be done regardless of whether the failover was done to a physical, logical, or snapshot standby database. There is little risk in enabling Flashback Database to determine its storage requirements - it can be disabled while the primary is open if necessary. 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. Moorestown, New Jersey, United States. Multiplexing SRLs merely adds unnecessary IO and can increase commit latency. Add an entry to the oratab file for the standby, db1:/u01/app/oracle/product/11.1.0/db_1:Y. Note that this does not guarantee no data will be lost. 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. (Yes, bystanders need Flashback Database too). US Coast Guard Auxiliary. value is 10. commands. Maximum availability SYNC or FASTSYNC or ASYNC, Maximum performance SYNC or FASTSYNC or SET MASTEROBSERVER TO allows you to manually change the observer configuration file. Figure 6-1 Relationship of Primary and Standby Databases and the Observer. Provides an automatic failover If you re-create the old primary database, it must be created as the standby type of the old standby database. This section will help you get started with creating a wrapper script to automatically start and restart the FSFO observer. Verify the primary database instance is open. broker opens all the PDBs on the new primary database and on the target standby The platform provides comprehensive services such as maintaining and monitoring databases to help the oracle databases in surviving during data corruption. A high lag limit may lead to more data loss but may lessen the performance impact of the primary database. All standbys other than the failover target are considered bystanders (v$database.fs_failover_status = 'BYSTANDER'). Once an immediate failover is started, the broker: Verifies that the target standby database is enabled. After you click the Reinstate button, Cloud Control begins reinstating the database. (Snapshot standbys are not included in the table because they are not supported as fast-start failover targets.). document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. 2. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM: If the specified log file is not accessible, or the LOGFILE IS option is not used, then the observer output is sent to standard output. Disabling Fast-Start Failover Using DGMGRL. The general approach seems to be CDB level failover to standby , so the failover takes place at CDB to CDB , in an event where a single PDB is experiencing an issue , we will have to failover the whole instance ..this will impact all PDB's on the CDB. 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. See "Database Service Configuration Requirements" for additional information about how the broker interacts with Oracle Restart. Fast-start failover allows the broker to automatically fail over to a previously chosen standby database in the event of loss of the primary database. been enabled on the database prior to the failover and there must be sufficient fast-start failover has not occurred to the target standby database. 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. environment variable to specify the default location for client-side broker files. If the currently configured mode is maximum protection, Cloud Control will downgrade the mode to maximum availability. Then the STOP OBSERVER command can be issued successfully on the former master observer. It is important that all SRVCTL add service options be identical on all the databases so that the services behave the same way before and after a role change. You can disable fast-start failover if necessary, by using the FORCE option. The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. To start an immediate failover, use the DGMGRL FAILOVER TO database-name IMMEDIATE command. Have a means of notifying someone if standby apply falls too far behind. The observe-only mode for fast-start failover enables you to test how fast-start failover will work in your environment. 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. 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. If any errors occur during either conversion, the broker stops the switchover. You must manually re-create the database as a standby database and then reenable it. Contains the callout configuration file, pre-callout script, mode when the fast-start failover target is a logical or physical standby database that By default the file is named fsfo.dat and is created in the working directory where the observer is started. If the Broker configuration is changed to make a bystander the new failover target (probably a good idea if the failed database will be down for a while), the observer will not automatically reinstate the former primary because it is no longer part of the FSFO configuration. 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. property. contains important information about the observer. Always try to perform a complete failover first unless redo apply has stopped at the failover target due to an ORA-752 or ORA-600 [3020] error. Twitter:https://twitter.com/hariprasathdba, In 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. configuration scripts and checks for errors or misconfigurations. 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. Note that if the V$DATABASE.FS_FAILOVER_STATUS column has a value of DISABLED, then any values returned for the remaining columns related to fast-start failover (V$DATABASE.FS_FAILOVER_*) become irrelevant. SQL> Select Database_role from v$Database; Additionally, the new master observer is identified in the output shown for the SHOW FAST_START FAILOVER and SHOW OBSERVER commands. failover to the target standby database. 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. You might, for instance, use this to allow the observer to monitor the databases using the same connect identifiers as the client applications. For more information, see SET MASTEROBSERVER TO. In a Data Guard environment primary database is open in read write mode and the standby database in read only mode for reporting purpose. Getting the Oracle Net configuration right is one of the key factors in a successful FSFO deployment. 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). A fast-start failover to the target standby database fails. Note that the FastStartFailoverThreshold property can be changed even when fast-start failover is enabled. Reinstatement of the failed primary database as a new standby database failed. This is cleared on both when the reinstatement has been completed. See the Cloud Control online help for more information. Regards, Narottam Tagged: dataguard dba rac Welcome! However, there may be situations in which you must disable fast-start failover when 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. Worked as a Development and Database Administrator. Each observer is identified by a name that you supply when you issue the START OBSERVER command. In Oracle Database 11g, the password file on the standby must be a physical copy of the password file on the primary due to security enhancements introduced in Oracle Database 11g. to set the time taken to detect a failure on the primary database: Set the FastStartFailoverThreshold The target standby database is synchronized with the primary database if it is a configuration operating in maximum availability or maximum protection mode, or the target standby database is within the lag limit if it is a configuration operating in maximum performance mode. If you do not want to use the default, you can define a specific group. Open another prompt and connect to SQLPLUS: Instead, the old primary database must be re-created as a standby from a backup of the new primary using the procedure described in How to Re-create and Reenable a Disabled Database. It uses these databases as a copy of the . 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.