It is also supported for fast-start failover to physical standbys in maximum availability data protection mode. You must set both $DG_ADMIN directory. If a single-instance primary database (either Oracle RAC or non-Oracle RAC), or if all instances of an Oracle RAC primary database are shut down with the ABORT option, the observer attempts a fast-start failover. See Reenabling Disabled Databases After a Role Change for more information. The DB_ROLE_CHANGE event will fire whenever a database is opened for the first time after a role transition. value of the FastStartFailoverThreshold property. The drain_timeout is specified in the SRVCTL STANDBY>connect /@STAN as sysdba Each observer has its own log file. Add the SRLs. Dataguard PDB level failover support for Multitenant Oracle 19c OBSERVER command, if this directory does not have the If the standby database's redo applied point is within that many seconds of the primary database's redo generation point, a fast-start failover will be allowed. If you are performing a complete failover, then all accumulated redo data is applied before the database role is changed to primary. This support note is available at http://support.oracle.com. Oracle Data Guard Broker is a utility that can help you manage your Oracle Data Guard. The broker preserves the protection mode that was in effect prior to the failover. 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. During a switchover, the primary database transitions to a standby role, and the standby database transitions to the primary role. Remember to check Flashback Database history before aborting the primary. Check the Undo tablespace Usage in Oracle, Exclude/Include option in EXPDP and IMPDP Datapump, Missing Dependencies Python Core / win32api, Stop the EXPDP/IMPDP Datapump Job in Oracle, Find the temp usage by sessions in Oracle, Create & grant permission to directory in Oracle, Check the Patch Applied to the Oracle Database. This When you start a switchover, the broker verifies that at least one standby database, including the primary database that is about to be transitioned to the standby role, is configured to support the overall protection mode (maximum protection, maximum availability, or maximum performance) after the switchover is completed. You can, however, perform a manual failover to a snapshot standby. failure on the 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. Note that a switchover operation may be started before the specified wait There are normally two situations when this operation will be performed: a planned outage for maintenance of the primary database or disaster recovery. variable must have read, write, and execute permissions for the directory owner It is very much useful, when the organization has multiple standby sites. You can optionally indicate the database health conditions that should cause fast-start failover to occur. specified, the file is stored in an appropriate directory under the broker's 2. After the former primary database has been repaired, the observer reestablishes its connection to that database and reinstates it as a new standby database. Set this property for the primary and target standby database if you want the observer to use a different connect identifier than that used to ship redo data (that is, the connect identifier specified by the DGConnectIdentifier property). There may or may not be data loss depending upon whether your primary and target standby databases were synchronized at the time of the primary database failure. The following steps all require the database to be in a mounted (not open) state. If there is more than one standby database in the configuration, you must explicitly set the FastStartFailoverTarget property on the primary database to name one or more candidate target standby databases. It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. Manual failover can be performed even if the pre-condition checks are not met. If the protection mode was at maximum availability or maximum performance, it remains unchanged. Oracle recommends configuring Flashback Database on every database so that if failover occurs to a physical standby database, you can more easily reinstate any disabled standby databases. flashback logs on that database. Verify the primary database instance is open. miliseconds. Using Shared Server (MTS) or connection pooling can result in unpredictable behavior. If possible, confirm that fast-start failover has not See Reenabling Disabled Databases After a Role Change. Fast-start failover will not be attempted for the other types of database shutdown (NORMAL, IMMEDIATE, TRANSACTIONAL). To specify which observer can be a master observer when a database is in 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. This action will result in loss of data and the possibility of two databases in the configuration simultaneously assuming the primary database role. The SHOW CONFIGURATION command will show you which databases can be reinstated and which databases must be re-created. For example, if the old standby was a physical or snapshot standby, then the old primary must be re-created as a physical standby. In 10g, a single wallet can be used for multiple observers, but they must all use the same SYS password. Oracle recommends that this property be set to a value that is small enough to allow timely detection of faults at the primary database, but large enough to limit the overhead associated with periodic observer connections to an acceptable level. The observer does not need to coordinate fast-start failover when fast-start failover is disabled, so the primary and target standby do not nominate a master observer until fast-start failover is enabled. Errors occurring for any other configuration members will not impede the switchover. This directory is created when you run the Please contact us at contactus@smarttechways.com. alter database recover managed standby database cancel; Step:3 The below commands will help to bring up standby as primary. set the ObserverPingInterval and stored in the specified path using the default file names. callout configuration scripts fsfo_precallout and Note: You can also use TNS aliases defined in the tnsnames.ora file when setting the local_listener parameter. If both of those observers are unavailable, the observers When a primary loses contact with both the failover target and the observer simultaneously, it enters a "stalled" state (v$database.fs_failover_status = 'STALLED') and any sessions still connected to the primary will block on commit. The broker first converts the original primary database to run in the standby role. It has two parts in the following order: Configuration declaration this section is mandatory. The However, there may be situations in which you must disable fast-start failover when There can be up to four Example 6-2 Sample Observer Configuration File. become the master observer. time specified in the WAIT option. After a failover, the original primary database can no longer participate in the Data Guard configuration. Bystander standby databases may be disabled by the broker during the failover, and they must be reinstated or re-created before they can serve as standby databases to the new primary database. If you are not using Oracle Clusterware or Oracle Restart, then you must create static service names so that the observer can automatically restart a database as part of reinstatement. FastStartFailoverLagLimit configuration property is set to zero) or fsfocallout.ora. Then set the configuration protection mode to maximum availability. directory has the same permissions as its parent directory. Dataguard Configuration details:- Login in to Standby Server:- Step:1 Check the database role and open_mode Select name,open_mode,database_role from v$database; Step:2 Cancel the MRP process alter database recover managed standby database cancel; Step:3 The below commands will help to bring up standby as primary Data Guard. See Enabling Fast-Start Failover for more information. 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. The configuration must be operating in either maximum availability mode or maximum performance mode in order to be able to switch over to a logical standby database. They must be re-created from a copy of the new primary database. Oracle Data Guard helps you change the role of databases between primary and standby using either a switchover or failover operation. You can use the maximum protection, maximum availability, or maximum (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.). In cases where In previous releases, OCI and ODP.NET clients receive FAN notifications via Oracle Advanced Queuing (AQ). Displays the current fast-start failover mode. Now it will return PRIMARY. If the status is SUCCESS, you're ready to start testing role transitions. 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. Required fields are marked *. Note that role changes to logical standby databases always result in physical standby database bystanders being disabled. status before the crash. If Flashback Database history is insufficient, the observer will not be able to reinstate and you will have to manually reinstate from backup or by primary duplication. Failovers become routine. Improper Oracle Net configuration is a leading cause of reported FSFO issues. To verify this change, again query the Database_role column of V$DATABASE. This may result in data loss. using the same SYS credentials you used when you connected to the See Sources of Diagnostic Information for details about the broker's drc* log files. broker opens all the PDBs on the new primary database and on the target standby The environment is a single instance database without any grid Infrastructure components.