data guard failover steps data guard failover steps

Automatic failover quickly and reliably fails over the standby Autonomous database to the primary database role, without requiring you to perform any manual steps. specified by the ObserverPingInterval property. They rely on Oracle Data Guard for high availability databases, with a standby database running in a different availability zone. This allows for redundancy in your Data Guard observer setup as well. In Oracle RAC configurations, the Inaccessible Logfile and Stuck Archiver health conditions may only be applicable to a single instance. The broker automatically reenables the database as part of reinstating it. The NetTimeout property specifies the number of seconds LGWR will block waiting for acknowledgment from the standby in synchronous mode before considering the connection lost (corresponds to the NET_TIMEOUT option of log_archive_dest_n). 2. the Steps To Congure Oracle 11g Data Guard Physical Standby associate that we give here and check . lower detection times for primary database failures. When using DGMGRL, you need to issue the SWITCHOVER command, specifying the name of the standby database that you want to change into the primary role. Ensure that the required permissions are granted to the DG_ADMIN Enabling Fast-Start Failover describes how to start observers as a part of the step-by-step process to enable fast-start failover. Clusterware: The broker notifies Oracle Clusterware to stop active If the new primary database was a primary database in the past, and had block Application calls to DBMS_DG.INITIATE_FS_FAILOVER. By default, the broker always determines whether bystander standby databases will be viable standby databases for the new primary when performing a complete failover. See the Oracle Reference and Data Guard Administrator guides for your release for details. the names of the scripts created in the previous step. For instance, you could log into the system running observer1 to stop observer2. Archiver is unable to archive a redo log because the device is full or unavailable. The real test of the configuration is a successful role transition in both directions with both switchover and FSFO failover. After an immediate failover completes, all the standby databases in the configuration, regardless of their type, are disabled. 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. The The command fails if the file does not exist. session. Whenever possible, you should switch over to a physical standby database: If the switchover transitions a physical standby database to the primary role, then: The original primary database will be switched to a physical standby role. Clusterware agent that the failover completed, the Oracle Clusterware agent opens PDBs Use Recovery Manager (RMAN) to back up the PeopleSoft database on a regular backup schedule. This can be avoided by first disabling fast-start failover with the FORCE option on the target standby. RAM). (Oracle Call Interface) client that connects to the primary and target standby databases In the following example, a service named sales is configured to be active in the PHYSICAL_STANDBY role on the primary database NORTH. The database on which the procedure is called notifies the observer. This is typically done for planned maintenance of the primary system. In a Data Guard environment primary database is open in read write mode and the standby database in read only mode for reporting purpose. These commands can be issued from the DGMGRL command line, but it is not necessary to log on prior to using them. In this case, Flashback Database cannot be used to reinstate databases. Disabling fast-start failover with the FORCE option when connected to the target standby database guarantees that fast-start failover will not occur. If both of those observers are unavailable, the observers occurred to the target standby database prior to disabling fast-start Create a pre-callout script, or a post-callout script, or both. It provides a way to quickly restore a database to a previous point in time or SCN using on-disk data structures called flashback logs. ERROR: Unable to verify the graphical display setup. If it exists, and it contains a pre-callout script location, In order to fully automate switchover, Broker needs SYSDBA credentials in order to restart one or both databases. If the FastStartFailoverPmyShutdown configuration property is set to TRUE, the primary database will shut down after FastStartFailoverThreshold seconds has elapsed if redo generation has been stalled and the primary database is unable to reestablish connectivity with either the observer or target standby database. The primary database can be opened even if there is no acknowledgement from the observer or target standby. For example: Fast-start failover occurs if both the observer and the target standby database lose connection to the primary database for the period of time specified by the FastStartFailoverThreshold configuration property. 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. The environment is a single instance database without any grid Infrastructure components. The syntax for the optional definition of a broker configuration group is: The group definition section is optional. set the ObserverPingInterval and In short, the failover is the deformation of the production (primary) database and activating standby database as the primary. Currently, this state can be detected only when the database is open. Oracle Database 10g databases running versions prior to 10.2.0.4 will remain in a stalled state until aborted or signaled to remain the primary by the observer once connectivity has been restored. Be aware that if you issue the following manual commands on either of those databases, then both the SALESRO and SALESRW services would be started on the databases regardless of what you may have earlier specified with the SRVCTL -role qualifier. isolated. After a failover, the original primary database can no longer participate in the Data Guard configuration. Oracle Data Guard Concepts and Administration provides information about setting up the databases in preparation of a switchover. Note that this does not guarantee no data will be lost. 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. Disabling Fast-Start Failover Using DGMGRL. 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 In the following example, ObserverReconnect is set to 30 seconds. The steps in this section describe the tasks involved to perform a manual failover. Then, click Continue to proceed to the next page. SWITCHOVER command, and the databases are managed by Oracle Oracle Data Guard Command-Line Interface Reference for more information about these broker commands. If the standby database is not enabled for management by the broker, then the failover cannot occur. A database in the primary role will not open until it has verified with the observer that it is still the primary. post-callout script, and pre-callout success file for the broker 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. Unlike ORLs, SRLs should be created with only one member per group. 4. If the Broker configuration is changed to make a bystander the new failover target (probably a good idea if the failed database will be down for a while), the observer will not automatically reinstate the former primary because it is no longer part of the FSFO configuration. Once an immediate failover is started, the broker: Verifies that the target standby database is enabled. Broker maintains these parameters by issuing ALTER SYSTEM commands as appropriate during role transitions, database startup/shutdown, and other events. present, you must start the observer manually using the following A number of prerequisites must be met on the primary in order to use Fast-Start Failover. list of the observers that can become the master observer when that 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. The standby can be physical or logical and there can be multiple standbys, but only one of the standbys can be the failover target at any given time. Choosing the standby database with the smallest transport lag can minimize the amount of data loss and in some cases, incur no data loss at all. file, observer runtime data file (fsfo.dat), fast-start failover callout 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. the preferred method for starting an observer. For information about event notification and database connection failover support for global services, see the Oracle Database Global Data Services Concepts and Administration Guide. Follow the guidelines described in Choosing a Target Standby Database. 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. Now test FSFO failover back to the original primary. After you click the Reinstate button, Cloud Control begins reinstating the database. Restarts the new standby (former primary) database if the switchover occurs to a physical standby database, and Redo Apply begins applying redo data from the new primary database. (See Disabling Fast-Start Failover for important considerations when using the FORCE option.). 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. Busca trabajos relacionados con New sql server failover cluster installation greyed out o contrata en el mercado de freelancing ms grande del mundo con ms de 22m de trabajos. 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. connection, or the database on which you issued the disable fast-start failover Use the EMCLI verb dg_configure_observers. 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. In such a case, no attempt is made to transmit any unsent redo from the cascader to the terminal standby. OBSERVE-ONLY: Fast-start failover is enabled in observe-only mode. Set the, Configure the connect descriptor with a single network name that is registered with a global naming service such as DNS or LDAP. gets enabled and then begins monitoring. Contains the observer runtime data file for the broker Instead, it allows an observer that is monitoring the configuration to initiate a fast-start failover should database conditions warrant a failover. SQL> Select Database_role from v$Database; Sets up redo transport from the new primary to the other members of the configuration, Starts Redo Apply services on the new standby, Ensures the other standbys in the broker configuration are viable to the new primary, Integrates with Oracle Clusterware and Oracle Global Data Services (GDS) to ensure that the proper services are started after a role change. The following assumes that the standby host has been setup according to Oracle's recommendations and that the operating system, accounts, security, resource limits, directory structure, etc. 8.2 Private Cloud Appliance and . The following sections describe how to perform manual failovers: Reenabling Disabled Databases After a Role Change. The redo transport mode used to send redo to the target standby database or the database currently in the primary role. This list contains some recommendations to obtain better performance when using fast-start failover. Among many benefits of using this utility, I highlight that while using it, it will not need manual intervention to recover the databases or eventually a switchover in case the primary database becomes unavailable. The target standby database is enabled and is in the APPLY-ON state. SQL>SHUTDOWN IMMEDIATE; When the standby becomes available again, the primary and standby re-synchronize and resume synchronous redo transfer. A snapshot standby cannot be the target of a switchover or fast-start failover operation. Use broker configuration properties to set the time taken to detect a See Reenabling Disabled Databases After a Role Change. operation: Example 6-1 Fast-start Failover Configuration See FastStartFailoverTarget for more information about this property. LGWR is unable to write to any member of the log group because on an I/O error. FAN server-side callouts can be configured on the database tier. Oracle Database PL/SQL Packages and Types Reference, Stop the observer from any computer system in the broker configuration, as described in, Start the observer on the new computer system, as described in Step 8 of, Enable fast-start failover using the DGMGRL, Shut down the primary database and the target standby database using either DGMGRL, Oracle Database Global Data Services Concepts and Administration Guide, Oracle Real Application Clusters Administration and Deployment Guide, Configure the connect descriptor for connect-time failover. Displays the current fast-start failover mode. database is in the primary role. Issue the following command while connected to any database in the broker configuration, except the database that is to be reinstated: The newly reinstated standby database will begin serving as a standby database to the new primary database. If you have an Oracle RAC primary database, consider specifying a higher value to minimize the possibility of a false failover in the event of an instance failure. 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. Some properties have changed between those releases. multi-tenant environments Know the database downgrade steps in case the upgraded database isn't compatible with the environment Discover the features and benefits to the organization when it moves from the old database . In order to maintain separation of Broker and non-Broker activity, a second static service is recommended. If you expect the network to be disconnected for a long time and Enable Fast-Start Failover Using Cloud Control. At a minimum, you must set db_unique_name. 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. 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). The observer is very lightweight, requiring few system resources. Any standby database that was disabled by the broker must be reinstated or re-created, as described in Reenabling Disabled Databases After a Role Change, before it can be a standby database for the new primary database. Since a fast-start failover (automatic failover) could become a false failover when the observer or the standby database cannot connect to the primary database within a specific time, which may cost the database to lose some transactions followed by reinstating or recreating the standby database (the former primary database). For example, if the old standby was a physical or snapshot standby, then the old primary must be re-created as a physical standby. The default name of the callout configuration file is The simplest way to do this is to abort the primary. You can start, stop, and show observers for a group of configurations. The terminal session will appear to hang at this point. The master observer waits the number of seconds specified by the FastStartFailoverThreshold configuration property before attempting a fast-start failover when the primary database has crashed or has lost connectivity with the observer, as in the following situations: The primary database loses its connections with both the observer and target standby database. A broker configuration can belong to multiple groups. 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. On Windows, the directory specified by the DG_ADMIN If a group name is not specified, then SHOW OBSERVERS alone is also a valid command. 1 second. The physical and snapshot standby databases will have to be re-created from a copy of the new primary database. STANDBY>connect /@STAN as sysdba Issue the following SRVCTL commands so that both databases in the Data Guard configuration know about the two potential services for each database: To start things up initially, you must manually start the services on the right node. To see if your primary has already met a prerequisite, follow the instructions in the Verify section. It's generally a good idea to store the state file in a directory associated with the database to avoid locking issues when running multiple observers on the same host.