The broker reinstates the database as a standby database of the same type as the former standby database of the new primary database. Database services can be configured to be active in specific database roles on Oracle RAC databases and on single-instance databases managed by Oracle Restart. With a value of TRUE for this property, the primary will shut down after being stalled for the number of seconds specified by the FastStartFailoverThreshold property. As a result, there is no guarantee that the observer will not perform a fast-start failover to the target standby database if the observer determines that conditions warrant a failover. The walkthrough begins with a single database that will become the primary of a Data Guard configuration. 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. Read-Only Standby and Active Data Guard The platform provides comprehensive services such as maintaining and monitoring databases to help the oracle databases in surviving during data corruption. STOP OBSERVING, and SET $DG_ADMIN directory. Apply services on all other bystander standby databases automatically begin applying redo data received from the new primary database. In a Managed Instance with multiple databases in Azure we can have high availability.
Manual Failover in Data Guard - ORACLE-HELP One is the master to set the time taken to detect a failure on the primary database: Set the FastStartFailoverThreshold Determine the number and size of the Online Redo Log files (ORLs). The FORCE option disables fast-start failover on the database to which you are connected even when errors occur. You must then re-create it from a copy of the new primary database and reenable it as described in How to Re-create and Reenable a Disabled Database. 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). You can disable fast-start failover if necessary, by using the FORCE option. multiple, inexpensive servers is the basis for the failover and other fault-tolerance features that RAC provides. not already enabled, the observer waits until fast-start failover In maximum performance mode, the ability to automatically failover is restored Note: Data Guard requires dedicated server connections for proper operation. The simplest way to do this is to abort the primary. 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. It is also possible to initiate failover using the dgmgrl failover command. The minimum To enable fast-start failover with DGMGRL, issue the ENABLE FAST_START FAILOVER command while connected to any database in the broker configuration, including on the observer computer. Only the master observer can coordinate fast-start failover with Data Guard broker. We'll leave the other properties at their default values for the walkthrough, but you should become familiar with all of the Broker config and database properties. If the primary is unable to contact the standby after a user specified period of time (NET_TIMEOUT option of log_archive_dest_ n), it drops out of synchronous transfer mode and begins operating as though it were in Maximum Performance mode. STAN is now transitioned to the primary database role.Now your PHYSICAL STANDBY Database has become PRIMARY. If the WAIT option is included in the Step:1 Check the database role and open_mode These tasks assume that you are connected as SYS or SYSDG and that a primary and standby database are already set up in a broker configuration. If it exists, and it contains a pre-callout script location, Once an immediate failover is started, the broker: Verifies that the target standby database is enabled. You can specify particular conditions for which a fast-start failover should occur using either Cloud Control or the DGMGRL ENABLE FAST_START FAILOVER CONDITION and DISABLE FAST_START FAILOVER CONDITION commands. Select name,open_mode,database_role from v$database; Step:2 Cancel the MRP process Goal. SHOW OBSERVER command to confirm that the switch took place. *PATCH v5 0/6] Add Toshiba Visconti Video Input Interface driver @ 2023-01-11 2:24 Yuji Ishikawa 2023-01-11 2:24 ` [PATCH v5 1/6] dt-bindings: media: platform: visconti: Add Toshiba Visconti Video Input Interface bindings Yuji Ishikawa ` (5 more replies) 0 siblings, 6 replies; 42+ messages in thread From: Yuji Ishikawa @ 2023-01-11 . It must appear as the first part of an observer configuration file. Unlike ORLs, SRLs should be created with only one member per group. 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. 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. Make sure the last redo data transmitted from the Primary database was applied on the standby database. prolonged stall, either the observer or target standby database All Data Guard environments require the use of a password file in order to allow the databases to connect to each other. Before beginning a failover, first determine that there is no possibility of recovering the primary database in a timely manner, and ensure that the primary database is shut down. configuration file These are the actions the broker performs after you start a switchover. Getting the Oracle Net configuration right is one of the key factors in a successful FSFO deployment. This function can be called from a connection to either the primary or any standby in the configuration. For reliable startup, the initial connection should always be made to the primary. You can specify STOP OBSERVER ALL to stop all observers registered in a broker configuration. You cannot perform a switchover to a snapshot standby database unless you first convert it back to a physical standby database. Verify the target standby database is ready for failover. The same process should work for RAC environment as my colleague has . 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. Ensure that the required permissions are granted to the DG_ADMIN Restart the database to the mounted state, Use Cloud Control or DGMGRL to reinstate the database. callout configuration file. FAN events are always published through ONS. Failovers become routine. observer_hostname.log. the Steps To Congure Oracle 11g Data Guard Physical Standby associate that we give here and check . For example, if the limit specified is 30 seconds (the default), FSFO guarantees that all transactions that committed prior to 30 seconds ago are preserved during failover. 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. To maximize the benefits of FSFO, the observer should run on a different host than the primary and standby databases.
How To Use Local Data Processing and Oracle Data Guard for Source (Note that the target standby cannot be a far-sync instance. Disabling Fast-Start Failover Using DGMGRL. Because fast-start failover was not disabled on the target standby database, the observer may still attempt a fast-start failover to the target standby database should conditions warrant a failover. Manual failover gives you control over exactly when a failover occurs and to which target standby database.
Albino DeSantis - Senior System Engineer - US Coast Guard - LinkedIn What is true about data guard set up with fast-start failover (FSFO) in Oracle Cloud Infrastructure (OCI)? The existence of a .suc file, Observers continuously monitor the fast-start failover environment to ensure the primary database is available (described in When Fast-Start Failover Is Enabled and the Observer Is Running). This section lists the steps the master observer takes to determine if a fast-start failover is needed and then to perform one, if necessary. Required fields are marked *. 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. You might, for instance, use this to allow the observer to monitor the databases using the same connect identifiers as the client applications. 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. Step:5Bounce your database and verify database name its open mode and its role. 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. That process is shown here. DGMGRL to manage multiple observers on multiple configurations. You can enable fast-start failover from any site while connected to any database in the broker configuration. Now test FSFO failover back to the original primary. You may failover to a snapshot standby database.
Oracle FAN with Oracle Data Guard but without using Oracle Grid/ RAC command for more information about starting the The list is empty by default. 1. To see if your primary has already met a prerequisite, follow the instructions in the Verify section. The FastStartFailoverThreshold time interval starts when the observer first detects there might be a failure with the primary database. Controlfile is permanently damaged because of a disk failure. You can start, stop, and show observers for a group of configurations. While this eliminates the processing overhead associated with periodically establishing a new observer connection to the primary database, it also prevents the observer from detecting that it is not possible to create new connections to the primary database. Verify the configuration from both hosts. This can be avoided by first disabling fast-start failover with the FORCE option on the target standby. Once the primary database regains connectivity with the target standby database, fast-start failover will be disabled for all the databases in the 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. When performing a failover in a configuration whose standbys are all of the same type, choose the standby database that has the smallest transport lag. environment variable must have exclusive permissions wherein it can be accessed only 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. Immediate Failovers in Configurations Using Cascaded Standbys. Slightly less critical than making sure you've got a good primary is making sure the failed primary can be automatically reinstated. Now let's test switchover in the other direction. 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. They rely on Oracle Data Guard for high availability databases, with a standby database running in a different availability zone.
Guide to Oracle Data Guard Fast-Start Failover 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. It uses the connect identifier specified in the observer configuration file to locate the credentials for a broker configuration from the Oracle wallet. Some properties have changed between those releases. Note that a switchover operation may be started before the specified wait 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. Figure 6-2 The Observer in the Fast-Start Failover Environment. Make sure that your OS environment on the standby is setup. To enable fast-start failover, both the primary and target standby databases must be running and have connectivity, and satisfy all of the prerequisite conditions listed in Prerequisites for Enabling Fast-Start Failover. 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. In addition, a logical standby database may contain only a subset of the data present in the primary database. Data Guard. See Oracle Enterprise Manager Command Line Interface. They may be reinstated if Flashback Database is enabled on those databases. After the failover completes, the former primary database is automatically reinstated as a standby database when a connection to it is reestablished, if the FastStartFailoverAutoReinstate configuration property is set to TRUE. Suppose you have a primary database, BOSTON, and a standby database, CHICAGO. fsfocallout.ora. 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. 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. Immediately after issuing command in step 2, shut down and restart the standby instance STAN: In fact, failovers are so reliable, fast, and simple that switchovers become the exception rather than the rule.