Use Recovery Manager (RMAN) to back up the PeopleSoft database on a regular backup schedule. If the target standby database is a snapshot standby database, all of its instances must be restarted to the mount mode before performing failover. first recording that a fast-start failover cannot happen. In this case, the FS_FAILOVER_STATUS and FS_FAILOVER_OBSERVER_PRESENT columns will appear as shown in the following table and fast-start failover will not occur: Oracle Database Reference for more information about the V$DATABASE view. Note the primary and target standby must have connectivity for this command to complete successfully. fsfocallout.ora. time specified in the WAIT option. Ensure this file cannot be read by unauthorized users. The simplest way to do this is to abort the primary. command on the observer computer: The observer is a continuously executing process that is Synopsis. Observer sites monitor the fast-start failover environment. The following sections provide more information about the fast-start failover environment: When Fast-Start Failover Is Enabled and the Observer Is Running, Restrictions When Fast-Start Failover is Enabled, Shutting Down the Primary Database When Fast-Start Failover Is Enabled, Performing Manual Role Changes When Fast-Start Failover Is Enabled. Initiate the failover on the standby database STAN: SQL>connect /@STAN as sysdba SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH; SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY; 2. Otherwise, they must be re-created from a copy of the new primary database. You want to prevent fast-start failover from occurring because the primary database will resume service soon. directory. Your email address will not be published. Read-Only Standby and Active Data Guard Step:6 learning with R and Python are also covered in this step-by-step tutorial. The act of switching roles should be a well-planned activity. If client-side ONS configuration is used, the client-side ONS configuration file must specify the hostname and port of the ONS daemon(s) of the primary database and each standby database. 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. It may be possible to convert the old Primary into a Standby database now instead of having to do a time consuming duplicate again. Contains the callout configuration file, pre-callout script, Remember to check Flashback Database history before aborting the primary. A normal shutdown prevents a fast-start failover until the primary database and standby database are connected and communicating again. If the configured data loss guarantee cannot be upheld, The following sections describe how to perform manual failovers: Reenabling Disabled Databases After a Role Change. Displays when the primary and target standby databases are synchronized and the configuration is operating in maximum availability mode. exit. In the restore stage, Flashback Database restores the database to a point prior to the standby_became_primary_scn using the before-image blocks in the Flashback Database logs. Application calls to DBMS_DG.INITIATE_FS_FAILOVER. 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. ORACLE instance shut down. See Oracle Enterprise Manager Command Line Interface. To use a far sync instance with fast-start failover, the far sync instance transport mode must be set to either SYNC or FASTSYNC and the target standby database transport mode must be set to ASYNC. The observer is perfectly satisfied if all of the redo it needs to meet your durability requirements has been received by the failover target. There are prerequisites that must be met before the broker allows you to enable fast-start failover. Configure one or more active standby databases Minimize downtime for upgrades STOP OBSERVING, and SET Once an observer is started, no further user interaction is required. In maximum performance mode, the ability to automatically failover is restored Else, broker restarts the new 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. They may be reinstated if Flashback Database is enabled on those databases. Now we will see a step-by-step approach to perform a switchover between the primary and the logical standby database: . For manual failover, the observer is started and communicating with the target standby database. If the former physical standby database was running with real-time query enabled, the new physical standby database will run with real-time query enabled. 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. These FAN events can be used in the following ways: Applications can use FAN without programmatic changes if they use one of these Oracle integrated database clients: Oracle Database JDBC, Oracle Database Oracle Call Interface (OCI), Oracle Data Provider for .NET ( ODP.NET), or Universal Connection Pool for Java. You cannot perform a manual failover to the target standby database for the same reason. In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. Unlike ORLs, SRLs should be created with only one member per group. multiple, inexpensive servers is the basis for the failover and other fault-tolerance features that RAC provides. Step-by-step instructions for manual reinstatement are described in Reenabling Disabled Databases After a Role Change. Keep this trigger as simple and reliable as possible, limiting it to only what is absolutely necessary at the moment of role transition, since any failures at this point may affect availability. 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. gets enabled and then begins monitoring. Maximum Availability mode uses synchronous redo transfer and FSFO imposes the additional requirement that the redo is recorded in the standby redo log (SRL) of the target standby (AFFIRM option of log_archive_dest_ n). 1. Services that must be active in any given database role (primary, physical standby, logical standby, or snapshot standby) must be configured with the Server Control utility (SRVCTL) explicitly on each database where the service must be active. The broker preserves the protection mode that was in effect prior to the failover. If a single-instance primary database (either Oracle RAC or non-Oracle RAC), or if all instances of an Oracle RAC primary database fail, the observer attempts a fast-start failover. Facebook:https://www.facebook.com/HariPrasathdba Its primary job is to perform a failover when conditions permit it to do so without violating the data durability constraints set by the DBA. All Data Guard environments should enable force logging at the database level in order to guard against nologging tablespaces from being added. orapwd file=$ORACLE_HOME/dbs/orapw$ORACLE_SID. If fast-start failover is enabled you can still perform a switchover or a manual failover as long as certain conditions are met. Contains the observer runtime data file for the broker configuration file 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. The observer maintains state information in a file. the names of the scripts created in the previous step. Restore - Flashback Database restores the datafiles to the closest snapshot prior to the specified SCN. 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 . FSFO can provide substantial gains in high availability and disaster recovery preparedness for all environments, from inexpensive Cloud-based systems to global distributed data centers. 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. To run an observer as a background process, use the DGMGRL command START OBSERVER IN BACKGROUND. Fast-start failover can incur data-loss within the time specified by FastStartFailoverlagLimit. In the previous article, we have seen switching the role of Primary and standby database and failover Primary role to Standby database manually. There can be up to four OBSERVER command, if this directory does not have the What is true about data guard set up with fast-start failover (FSFO) in Oracle Cloud Infrastructure (OCI)? The redo transport mode used to send redo to the target standby database or the database currently in the primary role. Immediate Failovers in Configurations Using Cascaded Standbys. By default, the broker always determines whether bystander standby databases will be viable standby databases for the new primary when performing a complete failover. Group definition this section is optional. In 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. It is not reversible. After a failover, the original primary database can no longer participate in the Data Guard configuration. If the database is managed by Oracle Clusterware, broker does not open any pluggable It uses the connect identifier specified in the observer configuration file to locate the credentials for a broker configuration from the Oracle wallet. An observer is an OCI 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. The state file is locked when the observer is running to prevent multiple observers from using the same file. Thus, the validity of the values of these properties is not verified until after the switchover. By default, the observer creates this file in the current working directory when it is started and names the file fsfo.dat. Application Continuity is supported for Oracle Data Guard switchovers to physical standby databases. 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 minimum value of ObserverPingInterval is 100 The default value is 30 seconds and the lowest possible value is 5 seconds. See Oracle Data Guard Concepts and Administration for more information on using the ALTER SYSTEM FLUSH REDO statement. 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. You must ensure that the primary database is shut down prior to performing a manual failover. The database on which the procedure is called notifies the observer. This section describes how to configure an Oracle Net connect descriptor that meets this requirement. If this occurs, run 'stop observer' and try again. Otherwise, the DUPLICATE TARGET DATABASE command will fail with "RMAN-20208: UNTIL CHANGE is before RESETLOGS change". The observer is very lightweight, requiring few system resources. To determine if the configuration is ready for fast-start failover to occur, issue the DGMGRL SHOW DATABASE command, or query the V$DATABASE view on either the primary or target standby databases. 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. This support note is available at http://support.oracle.com. In a Managed Instance with multiple databases in Azure we can have high availability. configuration file exists. Failovers become routine. After a role change, the naming service can be updated with the new primary's address. drain_timeout amongst the active services. Verifies that the target standby database is enabled. stored in the specified path using the default file names. 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. When this command is issued, the actual Note: the FSFO observer version must match the database version. Once you set these properties, their values persist through role changes during switchover and failover. The original primary database will be restarted as a part of the switchover operation. The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. 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. alter database recover managed standby database finish; alter database activate standby database; Managed recovery process has been stopped between primary and standby database and standby becomes primary database. Note that the value of the FastStartFailoverPmyShutdown configuration property must be FALSE for the primary to stall indefinitely under these conditions. To start a switchover using Cloud Control, select the standby database that you want to change to the primary role and click Switchover. The subcommands for this verb include start, stop, setMaster, show, and delete_alternate_observer. Input commands are shown in shaded boxes in normal text. present, you must start the observer manually using the following Note that the broker does not use the properties to set up redo transport services and Redo Apply services until you actually switch over the primary database to the standby role. On the Oracle Data Guard Overview page in Cloud Control, select the standby database that you want to change to the primary role and click Failover. In 10g, a single wallet can be used for multiple observers, but they must all use the same SYS password. This walkthrough uses Maximum Availability mode to achieve "zero data loss". This list describes how the overall Oracle Data Guard protection mode is handled after a manual failover (complete or immediate). On primary database NORTH, execute the following: On standby database SOUTH, execute the following: Services that are to be active while the database is in the physical standby role must also be created and started on the current primary database regardless of whether the service will be started on that database or not. 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. Thus, the command-line prompt on the observer computer does not If you re-create the old primary database, it must be created as the standby type of the old standby database. The services required on the primary database are: Log Writer Process (LGWR) - Collects redo information and updates the online redo logs. These requirements are supplemental to those described in the documents previously referenced and in the following client-specific guides: Oracle Data Provider for .NET Developer's Guide for Microsoft Windows. If you want the broker to skip this viability check of bystander standby databases during a complete failover, thus decreasing the overall failover time, set the BystandersFollowRoleChange configuration property to NONE. If you cannot tolerate any loss of data, then ensure that the configuration protection mode is set to maximum availability or maximum protection. Even if you have successfully connected to a database server in the broker configuration using the CONNECT command, this command ignores the existing connection and uses the credentials stored in Oracle wallet. That is, if the observer is connected to any instance in the Oracle RAC, all instances will show a value of YES. If local_listener is already in use, add the Data Guard listener to the list. All physical and snapshot standby databases will be disabled and must be re-created from a copy of the new primary database after a switchover to a logical standby database. To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE. 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. The information in this guide is based on practical experience gained from deploying FSFO in a global corporate production environment. fast-start failover has not occurred to the target standby database. You must If you want to use one Oracle home to start multiple observers, with each observer monitoring a different fast-start failover configuration, use the FILE qualifier to specify a unique observer configuration file location for each configuration to be monitored. The advanced way is in the following article: Connect-Time Failover by a Dynamic Service Name. the ObserverPingRetry and ObserverPingInterval properties to achieve Chapter 9 of the Data Guard Broker documentation (10g and 11g) contains a description of each property. In this mode you will need to consider how much data loss is acceptable in terms of seconds and set the FastStartFailoverLagLimit configuration property accordingly. Fast-Start Failover allows Data Guard to automatically failover to a previously chosen standby database without requiring manual intervention to invoke the failover. environment that is guaranteed to either lose no data (when the DG_ADMIN environment variable is not set, the files are stored in configuration scripts and checks for errors or misconfigurations. observer, whether it is currently connected to the primary and target standby databases, This configuration property causes the former primary database to be automatically reinstated if a fast-start failover was initiated because the primary database was either isolated or had crashed. In addition, the database to be reinstated and the new SQL Apply on all other bystander standby databases automatically begin applying redo data received from the new primary database. Configure the TNSNAMES.ORA file on the observer system so that the observer is able to connect to the primary database and to the pre-selected target standby database. This property allows you to specify a priority ordered DGMGRL to manage multiple observers on multiple configurations. observers for a single Data Guard configuration. Problems with automatic reinstatement are frequently due to misconfiguration, so let's look at this in a bit more detail. operation. observers are registered, a directory named connectivity with target standby. Each database in a Data Guard configuration must have a unique name. See the START OBSERVER Steps that require the primary to be in a mounted (not open) state are grouped together in the section below entitled Steps Requiring a Bounce of the Primary. In this case, the observer cannot perform a fast-start failover even if conditions warrant a failover. If the FastStartFailoverPmyShutdown configuration property is set to TRUE, then the former primary database will have been automatically shut down and must be manually restarted before the master observer can attempt to reinstate it. Initiate the switchover on the primary database PRIM: The observer automatically starts the reinstatement process. Neither the primary database nor the logical standby database needs to be restarted after the switchover completes. 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. MASTEROBSERHOST TO command. Most of the network services used in a FSFO environment may use dynamic registration, but to enable Broker to restart instances during role transitions or during reinstatement after a failover, you must define a static service named db_unique_name_dgmgrl. This nomination is noted in the observer log file and in the broker log file (drc*.log). command for more information about starting the The procedure for using RMAN to create a standby database is fully explained in Appendix F of Oracle Oracle Data Guard Concepts and Administration document (10g Rel 2 and 11g Rel 1). In previous releases, OCI and ODP.NET clients receive FAN notifications via Oracle Advanced Queuing (AQ). After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. For more information, see SET MASTEROBSERVER TO. (as it might in maximum availability and maximum performance modes). For example: Ordinarily the observer connects once to the primary and does not attempt to reconnect unless the connection has failed. These are the guidelines for choosing a target standby database. On Linux/Unix, the directory specified by the DG_ADMIN environment You want to conduct a manual failover to any standby database in the configuration (for example, because a failure occurred on the primary database at a time when the primary and target standby database were not ready to failover). Now that we know switchovers work, it's time to test failovers. Steps to Create a Physical Standby Databa se 3 -3 Preparing the Primary Database 3 -4 FORCE LOGGING . Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. 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. If there is only one standby database in the configuration, you can skip this step and continue with Task 3. Note that the new primary database does not need to be restarted. files are stored in subdirectories of the DG_ADMIN directory. In order to apply redo data to the standby database as soon as it is received, use Real-time apply. The broker disables all of the physical and snapshot standby databases in the configuration. These clients can be configured for Fast Connection Failover (FCF) to automatically connect to a new primary database after a failover. Then, on the Fast-Start Failover Configure page, select the standby database that should be the target of a failover. If there are many actions that need to take place, put them in a separate script and use the trigger to run the script in an orphan process or thread independent of the database. The word ALL cannot be used as a group name because it is a reserved keyword. This is Displays only on a logical standby database that has not yet completed loading a copy of the primary database's data dictionary. If the primary database has multiple standby databases, then you can specify multiple fast-start failover targets, using the FastStartFailoverTarget property. In maximum availability mode, set the LogXptMode database property for both the primary and target standby databases to SYNC or FASTSYNC. During a switchover, the primary database transitions to a standby role, and the standby database transitions to the primary role. Database hosts are referred to as "a" and "b" hosts and the databases themselves are referred to as the "a" and "b" databases. OBSERVE-ONLY: Fast-start failover is enabled in observe-only mode. If the status is SUCCESS, you're ready to start testing role transitions. If it's not, DGB will not allow the failover to continue until the DBA has manually resolved any discrepancies. You can query the V$DATABASE view to verify that the observer is started and the configuration is ready for fast-start failover. The ObserverOverride configuration property, when set to TRUE, allows an automatic failover to occur when the observer has lost connectivity to the primary, even if the standby has a healthy connection to the primary.
Top 100 Private Equity Firms 2021, Elizabeth Olsen And Sebastian Stan Fanfiction, Who Is The Assistant District Attorney In Philadelphia?, Rebound Returns Drop Off Locations, How To Use Verifly App American Airlines, Articles D
Top 100 Private Equity Firms 2021, Elizabeth Olsen And Sebastian Stan Fanfiction, Who Is The Assistant District Attorney In Philadelphia?, Rebound Returns Drop Off Locations, How To Use Verifly App American Airlines, Articles D