Starting with Oracle Database Release 21c, use the DG_ADMIN Group definition this section is optional. A snapshot standby cannot be the target of a switchover or fast-start failover operation. In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. If the standby database is not enabled for management by the broker, then the failover cannot occur. Stops Redo Apply or SQL Apply on the standby database immediately, without waiting until all available redo data has been applied. To stop the observer when fast-start failover is disabled, the primary database must be running. database is managed by Oracle Clusterware, broker directs Oracle Clusterware to In maximum availability mode, the behavior depends on the value of the Oracle Data Guard provides the ability to create and maintain Standby databases at one or more sites These protect Oracle databases from database and server failures as well as site disasters Failover to one of the alternate sites can be set to happen automatically (fast-start failover) or manually if the primary database is not usable Once fast-start failover is enabled, the broker will ensure that fast-start failover 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. Use the VALIDATE STATIC CONNECT IDENTIFIER command to ensure the static services have been configured correctly. 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. If the database is managed by Oracle Clusterware, broker does not open any of the Issue the following commands on Primary database and Standby database to find out: This property specifies the amount of data, in seconds, that the target standby database can lag behind the primary database in terms of redo applied. You can manage observers through either the Oracle Data Guard Overview pages in Cloud Control or using DGMGRL commands. If you already have an FRA, you may need to increase its size in order to accommodate the Flashback Database files. For systems with multiple RAID controllers, consider creating SRLs such that their IO is balanced across the controllers. Now your old standby database is become primary database, it is highly recommended to consider immediate full backup of primary database. been enabled on the database prior to the failover and there must be sufficient Expected output is shown in blue text. The If the primary database is an Oracle Real Application Clusters (Oracle RAC) database, the master observer will attempt to connect to one of the remaining primary instances. See the START OBSERVER command for more information. 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. The state file is locked when the observer is running to prevent multiple observers from using the same file. It will return PRIMARY, The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. 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 describes how to configure and verify each prerequisite. In the following example commands, a service named PAYROLL is configured to be active in the PRIMARY role on the primary database NORTH. Instead, when broker notifies the Oracle If the group name is not provided, then a new observer is started for each broker configuration defined in observer.ora. To allow the database to register with the Data Guard listener, the listener endpoint must be added to the database's local_listener parameter. Displays only on the target standby database when it is SYNCHRONIZED with or is TARGET UNDER LAG LIMIT of the primary database, has connectivity to the observer, but the primary database does not have a connection to the observer. If fast-start failover is enabled and the Datafile Write Errors condition is specified, then a fast-start failover is initiated if write errors are encountered in any data files, including temp files, system data files, and undo files. 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. environment variable is set and the specified directory has the fsfo_hostname.dat. required permissions, DGMGRL reports an error. ), The RedoRoutes property on a far sync instance if it is being used to receive redo from the primary database and ship redo to the target standby database, The standby database that is the target of fast-start failover, A far sync instance if it is being used to receive redo from the primary database and ship redo to the target standby database, Unless the conditions listed in Performing Manual Role Changes When Fast-Start Failover Is Enabled have been met, To a standby database that is not configured as the fast-start failover target. The services required on the primary database are: Log Writer Process (LGWR) - Collects redo information and updates the online redo logs. By choosing the standby database with the least amount of unapplied redo, you can minimize the overall time it takes to complete the switchover operation. failover with the FORCE option on the primary database. It uses these databases as a copy of the . Then the STOP OBSERVER command can be issued successfully on the former master observer. Such preparation includes: Ensuring that standby redo log files are configured on the primary database. observer is still in contact with the standby. On Windows, the directory specified by the DG_ADMIN If the new primary database was a primary database in the past, and had block 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 master observer uses the value specified by either the DGConnectIdentifier or ObserverConnectIdentifier database properties to connect to the primary and fast-start failover target standby databases. The selected standby database that will be the fast-start failover target must receive redo directly from the primary database. Disabling Fast-Start Failover Using Cloud Control. Remember to check Flashback Database history before aborting the primary. must create a .suc and .err file in the the primary and target standby databases. The ObserverOverride and ObserverReconnect properties allow you additional control over the connection to the primary. The foundation of FSFO is Data Guard - a primary and at least one standby. If the target standby database is ready for failover, then the master observer immediately directs the target standby database to fail over to the primary database role. In a Managed Instance with multiple databases in Azure we can have high availability. They must be re-created from a copy of the new primary database. We suggest you try the following to help find what youre looking for: This document will guide you through configuringOracle Data GuardFast-Start Failover (FSFO) using a physical standby database. If fast-start failover is Flashing back a database is much faster and more seamless (one simple DDL statement) than traditional point-in-time or SCN-based recovery. Click Disable in the Fast-Start Failover wizard. It must appear as the first part of an observer configuration file. Verify the target standby database is ready for failover. VALIDATE 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. Archiver is unable to archive a redo log because the device is full or unavailable. The connect descriptor must contain the SERVICE_NAME parameter in either case. This is called failover. Data Guard uses Oracle Net (SQL*Net) for communication between the primary and standby databases and the FSFO observer. configuration. (If there are other conditions, unique to an application, that would warrant a fast-start failover then the application can be set up to call the DBMS_DG.INITIATE_FS_FAILOVER function and start a fast-start failover immediately should any of those conditions occur. When you configure data guard using OCI console, the default mode is set to maxprotection. If you perform a manual failover when fast-start failover is enabled: The failover can only be performed to the current target standby database. Improper Oracle Net configuration is a leading cause of reported FSFO issues. For example, if a physical standby database was in the APPLY-OFF state, it will remain in the APPLY-OFF state. ob2-host can be a master observer when In such a case, no attempt is made to transmit any unsent redo from the cascader to the terminal standby. If there are physical or snapshot standby databases in the configuration and the switchover occurs to a logical standby database, you need to re-create those databases from a copy of the new primary database and then reenable those databases, as described in Reenabling Disabled Databases After a Role Change. In an environment where there are multiple observers configured, stopping the master observer is not allowed unless it is the last running observer. The primary and target standby must have connectivity for the STOP OBSERVER command to complete successfully. This list describes conditions in which the broker cannot automatically reinstate the former primary 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). The terminal session will appear to hang at this point. The services include switchover, switchback and failover. Data Guard Configuration Details:-. Make some new changes and verify that they are preserved after failover. 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. The word manual is used to contrast this type of failover with a fast-start failover (described in Fast-Start Failover). *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 . Oracle Data Guard Command-Line Interface Reference for more information about these broker commands. After the fast-start failover completes successfully, the master observer will attempt to reinstate the former primary database as a new standby database when a connection to the former primary database is reestablished, and the FastStartFailoverAutoReinstate configuration property is set to TRUE. There are configuration requirements that must be met in order to publish and properly handle FAN events generated as the result of a broker-managed failover. See Sources of Diagnostic Information for details about the broker's drc* log files. directory specified by this variable does not exist, or the directory does not have the 5. Only the master observer can coordinate fast-start failover with Data Guard broker. Any apply delay must be removed before beginning a switchover. Note that if failover was performed on a snapshot standby database, the old primary must be either reinstated or re-created as a physical standby database. The former primary database is disabled. Download Ebook Oracle 11g 12c Data Guard With Asm Lab Practice A Complete Hands On Lab Practice To Manage A Data Guard . If the service has been configured to start automatically (-policy AUTOMATIC), then the service will automatically start only after a database role change. If there are no registered observers when fast-start failover is enabled, then the first observer started is designated as the master observer, and all others started later are backup observers. 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. (It is permissible to change the RedoRoutes property on all standby databases including target standby databases. In disaster situations where a failover is necessary, you may be more limited as to which standby database is the best one to pick up the failed primary database's activities. Displays only on the target standby database when either the primary or target standby database was shut down in a controlled fashion (using the NORMAL, IMMEDIATE, or TRANSACTIONAL, options, but not the ABORT option). Step:1 Check the database role and open_mode If the database is not managed by Oracle Clusterware, The FS_FAILOVER_OBSERVER_PRESENT column displays YES for the target standby database. Since the observer is a specialized instance of a dgmgrl session, the observer host should be installed with either the Oracle Client Administrator software or the full Oracle Database software stack. The Appendix provides information oncreating a simple wrapper script to start the observer as a background process. An spfile is required to persist these changes. The pre-callout script Choose a value high enough to avoid false disconnects from intermittent network trouble. RAM). You can also switch the master observer hosts for a group of configurations to one specific host. The example below takes advantage of the 11g RMAN Active Database Duplication feature. There are normally two situations when this operation will be performed: a planned outage for maintenance of the primary database or disaster recovery. Stores files related to the observer and callout configuration. The broker reinstates bystander standby databases that were disabled during a failover as standby databases to the new primary database. By default, the observer will initiate failover to the target standby if and only if ALL of the following are true: Oracle Database 11g Rel 1 introduced user configurable failover conditions that can trigger the observer to initiate failover immediately. (Snapshot standbys are not included in the table because they are not supported as fast-start failover targets.). Updates the broker configuration file to record the change in roles. 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. ObserverConfigFile is a DGMGRL session runtime property. 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/. alter database set standby database to maximize availability; If you don't already have a standby database, use your favorite method to create one. RMAN will copy the spfile from the primary, so this init.ora file is only needed during the first phase of the duplication. cannot use a different name for this file. Follow Smart way of Technology on WordPress.com. 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. 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. Regardless of the method you choose, the broker coordinates the role transition on all databases in the configuration. SHOW OBSERVERS [FOR fg_group_name ] shows information about observers for all configurations in the specified group. In a DataGuard environment when the Primary instance fails you need to go through the Failover and Reinstate processes in order to restore the database service, as described in the documentation: Changes a standby database to the primary role in response to a primary database failure. Log into the new primary and verify that the changes made it across. Examine the Broker configuration by logging into dgmgrl on the new primary. If failover is not possible for some reason, then the master observer will continue checking whether the standby database is ready to fail over. directory has the same permissions as its parent directory. directory does not have the required permissions, broker does the following: When you run DGMGRL commands, if a path and file name are explicitly specified for A fast-start failover occurred because a user-configurable condition was detected or was requested by an application by calling the DBMS_DG.INITIATE_FS_FAILOVER function. Create a trigger on this event to perform actions specific to your environment after a switchover or failover, such as updating the name resolution service to point to the new primary. This post will demonstrate the procedure to test Oracle Data Guard Fast-Start Failover by shutting down the server where the primary database is running from. Unlike ORLs, SRLs should be created with only one member per group. This can be done regardless of whether the failover was done to a physical, logical, or snapshot standby database. This allows for redundancy in your Data Guard observer setup as well. However, if you want the observer to reconnect to the primary database periodically as a means of testing the health of the network connection to the primary, then use the ObserverReconnect configuration property. The list is empty by default. The application needs to catch this error and respond accordingly. environment that is guaranteed to either lose no data (when the alter database recover managed standby database cancel; Step:3 The below commands will help to bring up standby as primary. Use Cloud Control or DGMGRL to perform either a complete (recommended) or an immediate failover. 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. (See Disabling Fast-Start Failover for important considerations when using the FORCE option.). Once you set these properties, their values persist through role changes during switchover and failover. When the primary database and the target standby database regain network connectivity, the broker will disable fast-start failover for the entire broker configuration. You must re-create the database manually from a copy of the current primary database and then reenable the database in the broker configuration. This can happen for either of the following reasons: A bystander standby database has applied more redo data than the new primary database itself had applied when it was a standby database. Now let's test switchover in the other direction. This means that in order for a flashback database operation to succeed, observer and the standby both lose contact with the primary. To achieve If the primary database does not have connectivity with the target standby database, fast-start failover remains enabled on the target standby database and the observer may still attempt a fast-start failover if conditions warrant a failover. Verify there are no active users connected to the databases. configuration named ConfigurationSimpleName. This results in the observer establishing a new connection to the primary database every 30 seconds. DG_ADMIN environment variable is not set, the files are stored in Write Engineering Change Proposal documentation and reports to request permission to install, replace . 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. Log in as a test user and make some changes that won't impact other parts of the system. To start an observer as a background process, use the DGMGRL Displays if the standby database's redo applied point lags 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. Enable Active Data Guard for read-only workloads. It has two parts in the following order: Configuration declaration this section is mandatory. If the You may failover to a snapshot standby database. Regards, Narottam Tagged: dataguard dba rac Welcome! The logs also contain other details about the actions that will be performed in case of a failover. It is instructive to watch the alert logs on both databases as well as the observer log after aborting the primary to gain insight into what happens during FSFO failover. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM: Credentials Required for Access to Broker Configurations. Ensure SPFILE is used SQL> sho parameter spfile 2. 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. The string "NONAME" cannot be used as an observer name. 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. environment variable must have exclusive permissions wherein it can be accessed only on particular instances based on the service configuration. configuration named ConfigurationSimpleName. To install Oracle Data Guard, you need to create two Azure VMs on the same availability set: The primary VM (myVM1) has a running Oracle instance. 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. Flashback Database is a continuous data protection (CDP) solution integrated with the Oracle Database. If a non-zero value is specified for the If the primary and target standby databases do not have network connectivity or if the database to which you are connected does not have network connectivity with the primary database, consider using DISABLE FAST_START FAILOVER with the FORCE option. LGWR is unable to write to any member of the log group because on an I/O error. Reinstatement of the failed primary database as a new standby database failed. It will also alert you to databases that have had Flashback Database disabled at some point after FSFO was enabled. Whether or not standby databases that were not the target of failover (bystander standby databases) are disabled depends upon how much redo data they have applied relative to the failover target and the standby type of the failover target: If the failover target is a physical or snapshot standby database, the original primary database must be reinstated or re-created in order to be a standby database for the new primary database. Waits for the target standby database to finish applying any unapplied redo data before stopping Redo Apply (if the target is a physical standby database) or SQL Apply (if the target is a logical standby database). If you performed a failover or switchover that requires you to re-create the failed primary database or standby databases that were disabled during the role transition, then follow the procedures in the Oracle Data Guard Concepts and Administration chapter, "Creating a Physical Standby Database" and also the Oracle Data Guard Concepts and Administration chapter, "Creating a Logical Standby Database.". You can use the broker's reinstate capability to make a failed primary database a viable standby database for the new primary. In addition, some standby databases may be disabled by the broker during the failover if the broker detects that they have applied redo beyond where the new primary database had applied. This is particularly useful when registering with multiple listeners where the parameter value would otherwise exceed the 255 character limit. Starting the Observer as a Background Process Using This section describes how to configure an Oracle Net connect descriptor that meets this requirement. db_domain . 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. Facebook:https://www.facebook.com/HariPrasathdba The name of the callout configuration file is fsfocallout.ora. Otherwise, they must be re-created from a copy of the new primary database. In fact, failovers are so reliable, fast, and simple that switchovers become the exception rather than the rule. Create a trigger based on the, Oracle Database PL/SQL Language Reference, Choosing a Target Standby Database for Switchover, Choosing a Target Standby Database for Failover, Scenario 9: Performing a Switchover Operation, Scenario 10: Performing a Manual Failover Operation, Database Service Configuration Requirements, Troubleshooting Problems During a Switchover Operation, How the Broker Performs a Complete Failover Operation, How the Broker Performs an Immediate Failover Operation, Setting the Protection Mode for Your Configuration, Scenario 7: Enabling Fast-Start Failover When a Far Sync Instance Is In Use, Description of "Figure 6-1 Relationship of Primary and Standby Databases and the Observer", Enabling Fast-Start Failover Task 7: Configure Actions Before and After Fast-start Failover (Optional), Directing a Fast-Start Failover From an Application, Fast-start Failover Callout Configuration Files, Oracle Data Guard Command-Line Interface Reference, Description of "Figure 6-2 The Observer in the Fast-Start Failover Environment", Oracle Enterprise Manager Command Line Interface. fast-start failover succeeds, if a post-callout script is specified in the fast-start Bystander standby databases that are not disabled by the broker after the switchover will continue operating in the state they were in before the switchover. Fast-start failover enables the Data Guard broker to rapidly and automatically failover to a previously chosen standby database without requiring manual intervention. In a Data Guard environment primary database is open in read write mode and the standby database in read only mode for reporting purpose. The v$database view has has columns specifically for monitoring FSFO status.