data guard failover steps data guard failover steps

OBSERVER command, if this directory does not have the STAN is now transitioned to the primary database role.Now your PHYSICAL STANDBY Database has become PRIMARY. If there is only one registered observer, then it works in the same manner that a single observer worked prior to the advent of multiple observers in Oracle Database 12c Release 2 (12.2.0.1). Unless action is taken to change the failover target to one of the bystanders, the new primary will be without a failover target until the former primary is reinstated as a standby. The example below takes advantage of the 11g RMAN Active Database Duplication feature. STOP OBSERVING [cfg_group_name] stops LOCAL observers running on this host (where this DGMGRL is running) for all broker configurations in a specified group. Therefore, the target standby never falls behind the primary Alternatively, if you intend to switch back to the original primary relatively soon, then you may re-enable the disabled standby databases after the switch back. 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. 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. only. 3. An observer is an OCI The foundation of FSFO is Data Guard - a primary and at least one standby. 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. drain_timeout amongst the active services. The role change is directed to the same standby database that was specified for the FastStartFailoverTarget database property on the primary database. This list describes conditions in which the broker cannot automatically reinstate the former primary database. Steps for FAILOVER the Dataguard environment Initiate reinstatement by mounting the database. The services include switchover, switchback and failover. In the following example, ObserverReconnect is set to 30 seconds. Ideally the primary, standby, and observer will be in geographically separate areas. created when the START OBSERVER command is issued. Use the SQL ALTER DATABASE MOVE DATAFILE command to rename or relocate an online data file on a physical standby that is a fast-start failover target if the standby is mounted, but not open. FAN events are published using Oracle Notification Services (ONS) for all Oracle integrated database clients in Oracle Database 12c and later. Data guard 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; Media Recovery - Once the restore is complete, recovery proceeds as a typical media recovery, applying redo from archived and online redologs and rolling back uncommitted changes with undo. Sign in to Azure first recording that a fast-start failover cannot happen. Complete Failovers in Configurations Using Far Sync Instances. If a group name is not specified, then SHOW OBSERVERS alone is also a valid command. Role Transitions: Switchover and Failover 1 -7 Oracle Data Guard Broker Framework 1 -9 C hoosing an Interface for Administering a Data Guard Configuration 1 -10 Oracle Data Guard: Architecture (Overview) 1 -11 Primary Database Processes 1 -12 . 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. 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.". The observer immediately initiates a fast-start failover, as long as the failover target database is in a valid fast-start failover state ("observed" and either "synchronized" or "within lag") to accept a failover. The physical and snapshot standby databases will have to be re-created from a copy of the new primary database. Cancel MRP process. Oracle 12c-Step by Step Manual Data Guard Switchover, Manual Upgrading Oracle Database From 11.2.0.4 to 12.2.0.1, Automatically Terminated The Blocking Session By Setting MAX_IDLE_BLOCKER_TIME, Apply Patching On Oracle 21c Database Release Update 21.7.0.0.0, Oracle 21c Point In Time Recovery of Pdb Database, Oracle 21c Cloning a PDB Database Using Sqldeveloper Tool. You can start the observer before or after you enable You must use the Oracle wallet to store the credentials for all broker configurations to be managed. Note that primary and standby databases must be licensed for Oracle RAC or Oracle Active Data Guard in order to use Application Continuity. standby database, host, or network failure, etc.). If you want to capture any logging generated by the observer, use the LOGFILE IS option on the START OBSERVER command, and ensure that the file name is unique. To do this, use the SET ObserverConfigFile and SHOW ObserverConfigFile commands. For instance, you could log into the system running observer1 to stop observer2. If a fast-start failover was initiated because the primary database had crashed or lost connectivity with the master observer and target standby database, then the master observer automatically attempts to reinstate the former primary database as a standby database, if the FastStartFailoverAutoReinstate configuration property is set to TRUE. When querying the V$DATABASE view, pay special attention to the following: The FS_FAILOVER_STATUS column, which can contain the values described in Table 6-2. If a non-zero value is specified for the contains important information about the observer. Start the observer by running dgmgrl and logging in using SYS credentials. It has two parts in the following order: Configuration declaration this section is mandatory. SQL>STARTUP; 1. configuration. After an immediate failover completes, all the standby databases in the configuration, regardless of their type, are disabled. Enabling fast-start failover and starting an observer process involves the following tasks. The behavior of the broker if the master observer fails depends on whether the broker configuration has one observer or multiple observers. You can switch over or manual failover to a bystander database. Use the Cloud Control Fast-Start Failover wizard or the DGMGRL ENABLE FAST_START FAILOVER command to enable fast-start failover. This is FastStartFailoverThreshold for reference information about the FastStartFailoverThreshold property. In an environment where there are multiple observers configured, stopping the master observer is not allowed unless it is the last running observer. In a Managed Instance with multiple databases in Azure we can have high availability. Data Guard Configuration Details:-. Table 6-2 FS_FAILOVER_STATUS Column of the V$DATABASE View. This nomination is noted in the observer log file and in the broker log file (drc*.log). Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. Upon detecting the break in communication, the observer attempts to reestablish a connection with the primary database for the amount of time defined by the FastStartFailoverThreshold property before initiating a fast-start failover. FSFO configurations in Maximum Performance mode may limit potential data loss by specifying the maximum allowable age of transactions that are lost during a failover. You can issue a The broker allows the switchover to proceed as long as there are no errors for the primary database and the standby database that you selected to participate in the switchover operation. 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. Installing and starting an observer is an integral part of using fast-start failover and is described in detail in the following sections: Oracle Data Guard Installation explains that you can either install only the Oracle Client Administrator or you can install the complete Oracle Database Enterprise Edition or Personal Edition on the observer system. 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. 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. This is to ensure that the service definition gets propagated to the physical standby database via the redo stream and thus allows for the service to be started on the physical standby database. Note: You can also use TNS aliases defined in the tnsnames.ora file when setting the local_listener parameter. Else, broker restarts the new For example: In the following example, assume the network between the primary database and the observer has failed. To perform specified actions before or after a fast-start failover In this case, disable fast-start failover using the FORCE option on the target standby database. fsfocallout.ora. Otherwise, the DUPLICATE TARGET DATABASE command will fail with "RMAN-20208: UNTIL CHANGE is before RESETLOGS change". For switchovers, understanding all of the factors can simplify the choice of which standby database to consider as your new primary database. Any broker configuration name that is referred to must exist in the configuration declaration section. *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 . directory does not have the required permissions. Note that enabling FSFO does not make the configuration ready for automatic failover - that requires an observer, which we'll get to next. Notice that the former primary is now disabled. If it reconnects to the primary database before the standby agrees to fail over, then the master observer will stop attempting to initiate a fast-start failover. 3. required permissions, the admin folder is created A simple example for *nix is provided below that will work with both releases. If you don't already have a Flash Recovery Area (FRA), you will need to create one for Flashback Database. Monitoring flashback database history and reacting when it drops below 30 minutes will save you time and improve availability. North_Sales is in the primary role. commands. specified, the file is stored in an appropriate directory under the broker's Manual failover to the fast-start failover target can be performed without receiving an acknowledgement from the observer. present, you must start the observer manually using the following The previous examples dealt with setting up only one service on a database. configuration file VALIDATE Regardless of the method you choose, the broker coordinates the role transition on all databases in the configuration. The following sections describe how to reinstate or reenable a database. Check the spelling of your keyword search. Failing over the database won't do much good if applications and other database clients don't know where the primary went. If the protection mode was at maximum protection, it is reset to maximum performance. A failed ping is a ping to Therefore, the primary database can continue processing transactions, even if the target standby database fails. Ensure that the required permissions are granted to the DG_ADMIN The FastStartFailoverLagLimit configuration property is only used by the broker when enabling fast-start failover for configurations operating in maximum performance mode. The former primary database is disabled. The broker first converts the original primary database to run in the standby role. second. is guaranteed to lose no more than the amount of For information about enabling fast-start failover, see Enabling Fast-Start Failover. In addition, a logical standby database may contain only a subset of the data present in the primary database. 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. DGMGRL can be used to manage multiple observers in a group of broker configurations. You cannot create the standby DB system in a different AD from the primary DB system. A complete failover can occur without any data loss, depending on the destination attributes of redo transport services, but an immediate failover usually results in some data loss. The walkthrough begins with a single database that will become the primary of a Data Guard configuration. A snapshot standby cannot be the target of a switchover or fast-start failover operation. When enabled, re-create the standby database. There is no data loss during a switch-over. Conditions shown in blue are enabled by default. Add the wallet location and override to sqlnet.ora. Enabling fast-start failover does not trigger a failover. session. Reconnect within the time specified by the FastStartFailoverThreshold property. Clusterware: The broker notifies Oracle Clusterware to stop active These are some points to consider before you begin a switchover. 1. Moorestown, New Jersey, United States. 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. directory. 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. redo generation on the primary database will be stalled. Change the failover target to the standby being switched over to, Change the failover target to the desired standby. The target standby database has contact with the primary database. Simply use DISABLE FAST_START FAILOVER. An spfile is required to persist these changes. However failing over to a snapshot standby database will require more time because the broker must first convert it back to a physical standby database. the primary and target standby databases. Add the primary database and each standby database to the address list. the primary role, use the PreferredObserverHosts usually within three seconds if fast-start failover is enabled. Use Cloud Control or DGMGRL to perform either a complete (recommended) or an immediate failover. If the To protect the files, it's good practice to store them in separate filesystems. It also requires Flashback Database to be enabled on both the primary and target standby databases. Broker changes database parameters during startup and role transitions via ALTER SYSTEM commands. Data Guard broker does not manage or store credentials. If the failover target is a logical standby database, the original primary database and all physical and snapshot standby databases in the configuration will be disabled. 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). 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. FB Page:https://www.facebook.com/dbahariprasath/? In this mode, the FastStartFailoverLagLimit configuration property is set to zero. To run an observer as a background process, use the DGMGRL command START OBSERVER IN BACKGROUND. Once you set these properties, their values persist through role changes during switchover and failover. Add the SRLs. For more details about managing redo transport services using database properties, see Managing Redo Transport Services. For each temporary table, verifying that temporary files associated with that table on the primary database also exist on the standby database. This document describes how to setup clients to connect to Data Guard databases (primary and standby) and configure automatic client failover such that in case there is role change due to switchover or . Use Recovery Manager (RMAN) to back up the PeopleSoft database on a regular backup schedule. Applications can initiate FSFO failover directly using the DBMS_DG.INITIATE_FS_FAILOVER procedure with an optional message text that will be displayed in the observer log and the primary's alert log. These scripts must be in the same directory as the If the observer is unable to regain a connection to the primary database within the specified time, then the observer begins a fast-start failover provided the standby database is ready to fail over. LGWR is unable to write to any member of the log group because on an I/O error. To start a switchover using Cloud Control, select the standby database that you want to change to the primary role and click Switchover. fast-start failover, you can issue the DGMGRL SHOW FAST_START FAILOVER, During the failover to the physical standby database, the Oracle 11g DGB performs the following steps: First, it validates that the target standby database is ready to accept the primary role. The state file is locked when the observer is running to prevent multiple observers from using the same file. there is a lost network connection, be aware that the observer may attempt a Automatic failover is optional and can be enabled or disabled on your Autonomous Container Databases with Autonomous Data Guard. If the group name is not provided, then a new observer is started for each broker configuration defined in observer.ora. The example uses 10 seconds. the observer configuration file is observer.ora. A far sync instance or Zero Data Loss Recovery Appliance is not a database and therefore cannot be the target of a role transition. An observer process is integrated in the DGMGRL client-side component of the broker and typically runs on a different computer from the primary or standby databases and from the computer where you manage the broker configuration. There's a big difference between a system that's FSFO enabled and one that's FSFO ready. failover configuration file, this script is run. When running the START The information shown by this command is the same as that shown by a SHOW OBSERVER command on each individual configuration. If this configuration scripts and checks for errors or misconfigurations. Notice that the terminal session appears to hang after starting 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. ObserverConfigFile is a DGMGRL session runtime property. ERROR: Unable to verify the graphical display setup. 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 you are more concerned about the performance of the primary database than a minimal loss of data, consider enabling fast-start failover when the configuration protection mode is set to maximum performance. irrespective of its content, indicates that the script executed successfully. ObserverConnectIdentifier allows you to specify different connect identifiers for the observer to use. The simple tests described in this guide are fine for making sure the basics are working, but you'll probably want to develop a more comprehensive set of tests suited to your environment and requirements. observer and the others are backup observers. isolated. While not strictly required, creating a wallet provides a secure way to store the credentials needed to automatically connect to the primary when starting the observer. restart the new physical standby database. WAIT option, broker waits for the amount of Tasks that must be performed before and after a fast-start failover performance protection mode with fast-start failover. Presetting database properties related to redo transport services, such as LogXptMode, NetTimeout, StandbyArchiveLocation, StandbyAlternateLocation, and RedoRoutes. This means that in order for a flashback database operation to succeed, observer and the standby both lose contact with the primary. Syntax for Mandatory Configuration Declaration. It uses these databases as a copy of the . The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. In order for Flashback Database to succeed, there must be sufficient history available in the Flashback Database logs and all of the redo generated between the restore point and the standby_became_primary_scn must be available. Instead, when broker notifies the Oracle have received all the redo data the primary has generated in order for automatic failover to on ob3-host and ob4-host will not DG BrokerDG BrokerData Guard BrokerOracleDGRMAN Duplicate . directory. FastStartFailoverLagLimit configuration property is set to zero) or You cannot perform a switchover to a snapshot standby database unless you first convert it back to a physical standby database. The master observer cannot connect to the target standby database, What Happens if the Observer Fails? FB Group:https://www.facebook.com/groups/894402327369506/ Create a pre-callout script, or a post-callout script, or both. 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. It comes with a GUI and command line interface. If fast-start failover is disabled, then manual failover may still be possible. Valid values are >= 100. 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. primary database must have network connectivity. Fast-start failover is inhibited in this case. Manual failover can be performed even if the pre-condition checks are not met. This action may result in two databases in the configuration simultaneously assuming the primary database role should fast-start failover occur. Client-side broker In the following example, a service named sales is configured to be active in the PHYSICAL_STANDBY role on the primary database NORTH. For Oracle RAC databases, see Oracle Real Application Clusters Administration and Deployment Guide for more information about configuring database services with the SRVCTL utility. If block change tracking is enabled on the primary, and the target On the new primary database STAN, perform a SWITCH LOGFILE to start sending redo data to the standby database PRIM. Now we will see a step-by-step approach to perform a switchover between the primary and the logical standby database: . Complete Failovers in Configurations Using Cascaded Standbys. Provides an automatic failover See Troubleshooting Problems During a Switchover Operation for more information. ORACLE instance shut down. If they are isolated from each other, then you must first disable fast-start failover by using the FORCE option, and then stop the observer. 3. fast-start failover has not occurred to the target standby database. Let's run the command on the primary database to validate if the environments are ready for the role transition : JITPRD> alter database switchover to JITSDB verify; alter database switchover to JITSDB verify * ERROR at line 1: ORA-16475: succeeded with warnings, check alert log for more details These commands can be issued from the DGMGRL command line, but it is not necessary to log on prior to using them. Bystanders are part of the Data Guard configuration, but not part of the FSFO configuration. FastStart Failover Ensues: Disaster strikes the primary database and its network connections to both the observer and the target standby database are lost. Immediate Failovers in Configurations Using Far Sync Instances. Without the credentials, Broker will complete the role transition, but will leave the databases in need of a manual restart. However, you can change the name or the location of the file if you start the observer using the DGMGRL START OBSERVER command and include the FILE IS qualifier. In previous releases, OCI and ODP.NET clients receive FAN notifications via Oracle Advanced Queuing (AQ). Careful consideration should be given before enabling fast-start failover for either of these conditions because doing so will supersede availability options provided by Oracle Clusterware. In this example, the original primary data is called PRIM and the original standby database is called STAN. In maximum availability mode, set the LogXptMode database property for both the primary and target standby databases to SYNC or FASTSYNC. Verify there are no active users connected to the databases. 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. The following sections describe these topics: Prerequisites for Enabling Fast-Start Failover, Viewing Fast-Start Failover Configuration Statistics and Status, Performance Considerations for Fast-Start Failover, Reinstating the Former Primary Database in the Broker Configuration, Shutting Down Databases In a Fast-Start Failover Environment. See the START OBSERVER An application should use caution when calling the DBMS_DG.INITIATE_FS_FAILOVER function because the observer will initiate failover, if at all possible. distance. 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 the Oracle Maximum Availability Architecture technical briefs at: When setting the FastStartFailoverLagLimit configuration property, consider these tradeoffs between performance and potential data-loss: A low lag limit will minimize data loss but may impact the performance of the primary database. Set both these properties to achieve a primary failure detection time of 1 The terminal session will appear to hang at this point. If you like a connect-time failover to survive across a data guard switchover, you need another way to do it. If the database is not managed by Oracle Clusterware, . The time interval starts when the observer first loses its connection to the primary database. SQL> Select Database_role from v$Database; You can also switch the master observer hosts for a group of configurations to one specific host. Database dismounted. You will then need to re-create the physical standby databases from a copy of the new primary database before you can reenable them. database is managed by Oracle Clusterware, broker directs Oracle Clusterware to