FastStartFailoverLagLimit property. If the database is managed by Oracle Clusterware, broker does not open any of the The service is then configured to be active in the PRIMARY role on the standby database SOUTH, so that it will be active on that database after a role transition. Set both these properties to achieve a primary failure detection time of 1 Fast-start failover is inhibited in this case. So SALESRW will start on CHICAGO (which is now the primary) and SALESRO will start on BOSTON (which is now the physical standby). SQL>ALTER SYSTEM SWITCH LOGFILE; If the switchover occurs to a physical standby database, and the former primary To stop the observer when fast-start failover is enabled, the primary database and target standby database must be connected and communicating with each other. Add an entry to the oratab file for the standby, db1:/u01/app/oracle/product/11.1.0/db_1:Y. Presetting database properties related to redo transport services, such as LogXptMode, NetTimeout, StandbyArchiveLocation, StandbyAlternateLocation, and RedoRoutes. 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. Es gratis registrarse y presentar tus propuestas laborales. Standby databases not involved in the switchover (known as bystander standby databases) continue operating in the state they were in before the switchover occurred and will automatically begin applying redo data received from the new primary database. You cannot perform a manual failover to the target standby database for the same reason. The broker initiates a failover after the number of seconds specified by this In an immediate failover, it is also possible to failover to a standby database (terminal standby) that gets redo from another standby database (cascader). Setting this property to 'TRUE' (the default) causes the primary to self-terminate. directory. The FS_FAILOVER_OBSERVER_PRESENT column, which indicates whether the observer is running and actively pinging the database. Except for testing purposes, it is not recommended that you start more than one observer on the same host for a Data Guard broker configuration. It has two parts in the following order: Configuration declaration this section is mandatory. You must then re-create it from a copy of the new primary database and reenable it as described in How to Re-create and Reenable a Disabled Database. $DG_ADMIN directory. RAM). If Flashback Database history is insufficient, the observer will not be able to reinstate and you will have to manually reinstate from backup or by primary duplication. Oracle Database 11g observers are incompatible with 10g databases and vice-versa. the observer on ob2-host to become the master If there is only one observer, then it is considered to be the master observer. The column value for V$DATABASE.FS_FAILOVER_STATUS will be SYNCHRONIZED in a configuration operating in maximum availability mode, and it will be TARGET UNDER LAG LIMIT in a configuration operating in maximum performance mode when ready to fast-start failover. gets enabled and then begins monitoring. Learn how your comment data is processed. See Enabling Fast-Start Failover for more information. A failover to a logical standby database requires that all physical and snapshot standby databases be re-created from a copy of the new primary database after the failover completes. Note: Many of the Broker database properties correspond to database spfile parameters. If the database is managed by Oracle Clusterware, broker does not open any pluggable There are many examples, and Ritesh Chhajer offers this example of doing a Data Guard switchover using dgmgrl: 1. FAN events are published using Oracle Notification Services (ONS) for all Oracle integrated database clients in Oracle Database 12c and later. variable must have read, write, and execute permissions for the directory owner 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. For example: Ordinarily the observer connects once to the primary and does not attempt to reconnect unless the connection has failed. 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. You need to consider all of the options at the time you are building your Oracle Data Guard configuration, including factors such as the characteristics of physical standbys versus logical standbys versus snapshot standbys, the network latency to your standby database sites, the computing capabilities at a future primary database site, and so on. Figure 6-2 shows the observer monitoring a fast-start failover configuration. Subsequent changes to the same block during the same snapshot are not recorded. Problems with automatic reinstatement are frequently due to misconfiguration, so let's look at this in a bit more detail. all of the same type (all physical or all logical standby databases), choose the standby To allow the database to register with the Data Guard listener, the listener endpoint must be added to the database's local_listener parameter. Duplicate configuration names in configuration definitions are not allowed. database is in the primary role. You can manually stop a specific observer or all observers. Configure Data Guard Broker to manage and monitor the Data Guard configuration. If the master observer detects an availability problem with the primary database, then it typically attempts to reconnect to the primary database within the time specified by the FastStartFailoverThreshold configuration property. A simple example for *nix is provided below that will work with both releases. collections and databases Set up replica sets and automatic failover in MongoDB Use sharding to scale horizontally, and learn how . 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. If the protection mode was at maximum protection, it is reset to maximum performance. The connect-identifier is a TNS alias defined in tnsnames.ora through which all instances of all databases in this Data Guard broker configuration can be reached. Verify the target standby database is ready for failover. cannot use a different name for this file. In this mode, the FastStartFailoverLagLimit configuration property is set to a non-zero value. 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). Note: if the observer loses contact with the primary, but the standby does not, the observer can determine that the primary is still up via the standby. When you start a switchover, the broker verifies that at least one standby database, including the primary database that is about to be transitioned to the standby role, is configured to support the overall protection mode (maximum protection, maximum availability, or maximum performance) after the switchover is completed. This guide uses the naming convention of appending an underscore followed by a letter to the db_name to create the db_unique_name. name of the observer log file is on particular instances based on the service configuration. Add the wallet location and override to sqlnet.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. 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). Client-side broker It is actually a low-footprint OCI client built into the DGMGRL CLI (Data Guard Broker Command Line Interface) and, like any other client, may be run on a different hardware platform than the database servers. Apply services on all other bystander standby databases automatically begin applying redo data received from the new primary database. connection, or the database on which you issued the disable fast-start failover Create a pre-callout script, or a post-callout script, or both. learning with R and Python are also covered in this step-by-step tutorial. To stop an observer currently designated as the master observer, first issue the SET MASTEROBSERVER command to designate a different observer as master observer. Overview of Switchover and Failover in a Broker Environment. If the new primary database was a primary database in the past, and had block 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. database (if real-time query is enabled). This brings up the General Properties page that provides a Reinstate button. The default This allows for redundancy in your Data Guard observer setup as well. For Oracle RAC databases, see Oracle Real Application Clusters Administration and Deployment Guide for more information about configuring database services with the SRVCTL utility. In a Managed Instance with multiple databases in Azure we can have high availability. The redo transport mode used to send redo to the target standby database or the database currently in the primary role. With increased latency comes decreased throughput; however, in some cases the difference in throughput may be made up by increasing parallelism. Steps for FAILOVER the Dataguard environment alter system set standby_file_management=auto; This parameter must be set before the primary can be opened in Maximum Availability mode. 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. 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. The Marketplace image that you use to create the VMs is Oracle:Oracle-Database-Ee:12.1..2:latest. See theFlashback Database section above for information on storage requirements. To change the FastStartFailoverTarget property to point to a different standby database, disable fast-start failover, set the FastStartFailoverTarget property, and reenable fast-start failover. If there is only one standby database in the configuration, you can skip this step and continue with Task 3. This property also affects whether the broker skips viability checks of bystander standby databases when a fast-start failover occurs. present, you must start the observer manually using the following This file contains connect identifiers to both the primary and the target standby databases. PRIM>STARTUP MOUNT; times that the observer retries a failed ping before it initiates a primary database. The default value is ALL. Before beginning a failover, first determine that there is no possibility of recovering the primary database in a timely manner, and ensure that the primary database is shut down. . Use the 'show fast_start failover' command to see which user configurable FSFO failover conditions are in effect. If the configuration contains physical, snapshot, and logical standby databases, consider choosing a physical standby database as the target standby database. On the Oracle Data Guard Overview page, click Database must be reinstated. A failover may or may not result in data loss depending on the protection mode in effect at the time of the failover. To proceed, you must first disable fast-start failover using the FORCE option, and then perform a manual failover. In an Oracle Data Guard configuration, the SRVCTL -startoption for a standby database is always set to OPEN after a switchover. Data Guard Switchover/failover to standby The standby database will be activated to serve as the primary database at some point in its life cycle. The FORCE option may be the preferred method for disabling To help you select an appropriate switchover or failover target, use the following DGMGRL commands which perform checks on the database to determine its readiness to complete a role change. What is true about data guard set up with fast-start failover (FSFO) in Oracle Cloud Infrastructure (OCI)? It will return PRIMARY, If automatic reinstatement fails, the broker will log errors and the former primary database will remain in the mounted state. In previous releases, OCI and ODP.NET clients receive FAN notifications via Oracle Advanced Queuing (AQ). As a result the observer may still initiate fast-start failover to the target standby database, if conditions warrant a failover. When a switchover is started, the primary and standby databases that are involved should have as small a redo lag as possible. SQL> select name,open_mode,database_role from v$database; NAME OPEN_MODE DATABASE_ROLE --------- -------------------- ---------------- MYTEST MOUNTED PHYSICAL STANDBY Step 2: Apply the following command to finish database recovery. The failover was to a logical standby database. This property specifies the amount of data, in seconds, that the target standby database can lag behind the primary database in terms of redo applied. It uses the connect identifier specified in the observer configuration file to locate the credentials for a broker configuration from the Oracle wallet. In an Oracle Data Guard configuration, the SRVCTL -startoption and -role are updated after switchover to reflect the current open mode and database role on the new primary and standby databases. To verify this change, again query the Database_role column of V$DATABASE. STOP OBSERVING, and SET The broker reinstates bystander standby databases that were disabled during a failover as standby databases to the new primary database. maximum availability and maximum performance modes, to avoid a In maximum availability mode, set the LogXptMode database property for both the primary and target standby databases to SYNC or FASTSYNC. You can find detailed information about all observers, including master observers and backup observers, in the V$FS_FAILOVER_OBSERVERS view. Permissions Required by the DG_ADMIN Directory. 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. (Oracle Call Interface) client that connects to the primary and target standby databases This is called failover. This allows Data Guard to remain functional during maintenance periods when the application listeners are down. In once the target standby database's redo applied point is no longer lagging behind the primary A complete failover is the recommended and default failover option. Set the FastStartFailoverThreshold property to specify the number of seconds you want the observer and target standby database to wait (after detecting the primary database is unavailable) before initiating a failover. PDBs. 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). 8.2 Private Cloud Appliance and . 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. Fast-start failover will not occur unless all instances comprising the Oracle RAC primary database are perceived to have failed. Use Recovery Manager (RMAN) to back up the PeopleSoft database on a regular backup schedule. Flashback Database stores its logs in the Flash Recovery Area (FRA), so the FRA must be large enough to store at least 60 minutes of Flashback Database history. The simplest way to do this is to abort the primary. But before enabling Flashback Database, you must enable Flash Recovery Area (FRA). 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 are the actions the broker performs after you start a complete failover. 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. 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. This document only talks about switchover involving physical standby database. You can start, stop, and show observers for a group of configurations. To disable fast-start failover, use the Fast-Start Failover wizard in Cloud Control or the DGMGRL DISABLE FAST_START FAILOVER [FORCE] command. The target standby database is enabled and is in the APPLY-ON state. After the former primary database has been repaired, the observer reestablishes its connection to that database and reinstates it as a new standby database. In fact, failovers are so reliable, fast, and simple that switchovers become the exception rather than the rule. For example, if a physical standby database was in the APPLY-OFF state, it will remain in the APPLY-OFF state. is only possible when the configured data loss guarantee can be To stop it, you can do either of the following: Choose the Stop Observer option on the first page of the fast-start failover wizard and click Continue at the bottom of the page. Bounce your database and verify database name its open mode and its role: SQL> shutdown immediate; ORA-01109: database not open Database dismounted. The examples shown in this section do not necessarily show the specific attributes you might need to use in your own environment. The original primary database can now be configured as a standby. Here's a one-liner observer startup for *nix. Examples of starting observers using DGMGRL are included in Scenario 6: Enabling Fast-Start Failover and Starting the Observer. FastStartFailoverLagLimit property. It is possible to manually perform a completer failover to a standby database that receives redo data from a far sync instance. Verify dmon process is running and broker parameters viz. Bystander standby databases can be shut down at any time in any order without impacting fast-start failover. It is then started and stopped on the primary database. Figure 6-1 shows the relationships between the primary database, target standby database, and observer during fast-start failover: Before Fast-Start Failover: Oracle Data Guard is operating in a steady state, with the primary database transmitting redo data to the target standby database and the observer monitoring the state of the entire configuration. Using Shared Server (MTS) or connection pooling can result in unpredictable behavior. fsfo_postcallout are stored in the same location as A broker configuration can belong to multiple groups. Note that the new primary database does not need to be restarted. Therefore, the detection time can be reduced to nearly
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