Manual failover to the fast-start failover target can be performed without receiving an acknowledgement from the observer. (Oracle Call Interface) client that connects to the primary and target standby databases (For example, if the DBMS_LOGSTDBY.SKIP procedure was used to specify which database operations done on the primary database will not be applied to the logical standby database.). The targets are referred to as candidate targets. By default the file is named fsfo.dat and is created in the working directory where the observer is started. Many customers use Oracle Database deployed on Amazon Elastic Compute Cloud (Amazon EC2) to run their Oracle E-Business Suite applications. Issue the following SRVCTL commands: Now the correct services are running on the correct databases. Oracle Data Guard Broker is a utility that can help you manage your Oracle Data Guard. The FORCE option disables fast-start failover on the database to which you are connected even when errors occur. 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. This may result in data loss. 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. 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. 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. learning with R and Python are also covered in this step-by-step tutorial. It must appear as the first part of an observer configuration file. If the credentials cannot be obtained, then the attempted command fails (but only for the broker configuration whose credentials have not been obtained). Use the oraenv script provided by Oracle. The guide attempts to be operating system agnostic; however, some examples may contain platform specific elements such as path and file naming conventions. fast-start failover succeeds, if a post-callout script is specified in the fast-start required permissions, DGMGRL reports an error. FS_FAILOVER_OBSERVER_HOST shows the name of the computer on which the master observer is running, FS_FAILOVER_OBSERVER_PRESENT shows whether or not the master observer is connected to the local 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. Issue the following commands on Primary database and Standby database to find out: In this case, the observer cannot perform a fast-start failover even if conditions warrant a failover. Commands For Managing Observers on Multiple Configurations. When the standby becomes available again, the primary and standby re-synchronize and resume synchronous redo transfer. After the patch has been successfully applied to all databases, take the following steps to enable fast-start failover and start the observer. If the database is managed by Oracle Clusterware, broker does not open any pluggable Click Failover. After Fast-Start Failover: The fast-start failover has completed and the target standby database is running in the primary database role. 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 . An observer can be moved from one computer to another through a process of stopping it on one system and and re-starting it on another. The terminal session will appear to hang at this point. The broker will not allow a switchover to a standby that has an apply delay configured (DelayMins property is set to a non-zero value). So SALESRW will start on CHICAGO (which is now the primary) and SALESRO will start on BOSTON (which is now the physical standby). ObserverConnectIdentifier allows you to specify different connect identifiers for the observer to use. The default Set both these properties to achieve a primary failure detection time of 1 FastStartFailoverLagLimit connectivity with target standby. You can register up to four observers to monitor a single Data Guard broker configuration. Complete Failovers in Configurations Using Cascaded Standbys. MASTEROBSERHOST TO command. Logical standby databases that are disabled during failover can be reinstated. A switchover guarantees no data loss and is typically done for planned maintenance of the primary system. Only the observer can initiate FSFO failover. Oracle Database PL/SQL Packages and Types Reference for more information about the DBMS_DG package. A switch-over allows the primary database to switch roles with its standby database. Immediately after issuing command in step 2, shut down and restart the former primary instance PRIM: Create a wallet and set the default username and password to the database's SYSDBA credentials (usually SYS). In a Managed Instance with multiple databases in Azure we can have high availability. the current working directory. Table 6-2 FS_FAILOVER_STATUS Column of the V$DATABASE View. 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. See Installing and Starting the Observer. 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. You can also specify a list of ORA- errors that will initiate FSFO failover. When the configuration has only one registered observer, if the primary and target standby databases stay connected but the connection to the observer is lost, then the broker reports that the configuration is not observed. if the observer is not running, The master observer and the target standby database are inconsistent with regard to the current state of the broker configuration, If the protection mode is maximum availability or maximum protection and the target standby database was not synchronized with the primary database at the time the primary database failed, If the protection mode is maximum performance and the apply point of the target standby database lags the redo generation point of the primary database by more than the amount specified by the FastStartFailoverLagLimit configuration property at the time the primary database failed. stored in the specified path using the default file names. Event notification and database connection failover support is available to database clients connected to local database services when a broker-managed failover occurs. Follow Smart way of Technology on WordPress.com. See Reenabling Disabled Databases After a Role Change for more information. What is true about data guard set up with fast-start failover (FSFO) in Oracle Cloud Infrastructure (OCI)? The behavior of the broker if the master observer fails depends on whether the broker configuration has one observer or multiple observers. 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. ZERO DATA LOSS: Fast-start failover is enabled with zero data loss. These are some points to consider before you begin a switchover. However, there may be situations in which you must disable fast-start failover when There are two types of failover operations: Graceful or "no-data-loss" failover and Forced or "minimal-data-loss" failover. Worked as a Development and Database Administrator. You have done a failover to your Standby database so it becomes the new Primary. 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. Automatic failover quickly and reliably fails over the standby Autonomous database to the primary database role, without requiring you to perform any manual steps. When the primary database and the (non-target) standby database regain network connectivity, the broker will propagate its current fast-start failover setting (ENABLED or DISABLED) to the non-target standby. These commands can be issued from the DGMGRL command line, but it is not necessary to log on prior to using them. Now it will return PRIMARY. 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. It's good practice to use separate listeners for application connections and Data Guard connections. environment variable to specify the default location for client-side broker files. Once you have completed the switchover back to the original primary, you may then reenable the physical and snapshot standby databases since they are still viable standbys for the original primary database. Run the RMAN utility and connect to the target (primary) and auxiliary (new standby). fsfocallout.ora. ConfigurationSimpleName represents fast-start failover through Cloud Control. When both databases have been restarted, you may restart the observer. the primary and target standby databases. Broker will verify that the configuration meets all prerequisites before enabling FSFO and will report any problems it finds. This is a good time to enable FSFO to make sure that all of the prerequisites have been met. We'll leave the other properties at their default values for the walkthrough, but you should become familiar with all of the Broker config and database properties. list of the observers that can become the master observer when that 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. For Active Oracle Data Guard, it will fail to open up a connection unless its in read-only mode. Instead, it allows an observer that is monitoring the configuration to initiate a fast-start failover should database conditions warrant a failover. It will return PHYSICAL STANDBY, prolonged stall, either the observer or target standby database Once you set these properties, their values persist through role changes during switchover and failover. This property also affects whether the broker skips viability checks of bystander standby databases when a fast-start failover occurs. are configured correctly. US Coast Guard Auxiliary. For example, to determine if fast-start failover can occur, the FS_FAILOVER_STATUS column displays either SYNCHRONIZED or TARGET UNDER LAG LIMIT and the FS_FAILOVER_OBSERVER_PRESENT column displays YES for the target standby database. (See Disabling Fast-Start Failover for important considerations when using the FORCE option.). For example, if the limit specified is 30 seconds (the default), FSFO guarantees that all transactions that committed prior to 30 seconds ago are preserved during failover. See the "DISABLE FAST_START FAILOVER" command in Oracle Data Guard Command-Line Interface Reference for more information. A switchover guarantees no data loss and is typically done for planned maintenance of the primary system. Then, on the Failover Confirmation page, click Yes to invoke the default Complete failover option. Make sure that xdpyinfo exist under PATH variable. observer. A normal shutdown uses SHUTDOWN NORMAL, SHUTDOWN IMMEDIATE, or SHUTDOWN TRANSACTIONAL. This is particularly useful when registering with multiple listeners where the parameter value would otherwise exceed the 255 character limit. Use Cloud Control or DGMGRL to perform either a complete (recommended) or an immediate failover. Instead, when broker notifies the Oracle only. When DGMGRL starts, if the DG_ADMIN For information about event notification and database connection failover support for global services, see the Oracle Database Global Data Services Concepts and Administration Guide. drain_timeout amongst the active services. A trigger on the DB_ROLE_CHANGE system event can be used to update the naming service and, with the proper client cache TTL settings, clients can connect to the new primary very quickly. The broker may not be able to disable fast-start failover on all databases in the broker configuration when you issue the DISABLE FAST_START FAILOVER FORCE command. What to do in case of failover: (Important note: Istanbul is the primary server and Baku is the standby server) 1. 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. This lets you take advantage of the broker's SQL Apply on all other bystander standby databases automatically begin applying redo data received from the new primary database. You must the observer on ob2-host to become the master the observer configuration file is observer.ora. ), 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. Do not attempt to reinstate the old primary database if an ORA-752 or ORA-600 [3020] error has occurred at the failover target. To start the observer with DGMGRL, issue the following Broker is a Data Guard management utility that maintains state information about a primary and its standby databases. 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. Be sure to include the Data Guard listener in the local_listeners database parameter. You must manually re-create the database as a standby database and then reenable it. Overall commit latency is increased by the round-trip network latency. To protect the files, it's good practice to store them in separate filesystems. Both Cloud Control and the DGMGRL CLI will do this automatically as part of failover. The broker reinstates bystander standby databases that were disabled during a failover as standby databases to the new primary database. If the broker performs a switchover or failover, then it starts the service SALESRW or SALESRO based on the current role of the database. Data Guard broker does not manage or store credentials. The broker allows a complete failover to proceed as long as there are no errors present on the standby database that you selected to participate in the failover. database is in the primary role. 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. Slightly less critical than making sure you've got a good primary is making sure the failed primary can be automatically reinstated. post-callout script, and pre-callout success file for the broker To move the observer to another computer: There is no need to disable fast-start failover when you move the observer. Performing failover : Step 1: Check Standby Database role. The required attributes vary depending on your configuration (including whether your environment is Oracle RAC-based or single-instance). If the primary database has multiple standby databases, then you can specify multiple fast-start failover targets, using the FastStartFailoverTarget property. FastStartFailoverAutoReinstate is set to FALSE, Another failover or switchover occurred after the fast-start failover completed but before the former primary database restarted, The master observer cannot connect to the former primary database, The former primary database cannot connect to the new primary database, The former primary database and the new primary database are not configured in the same fast-start failover environment, The former primary database was disabled because of a manual failover when fast-start failover was disabled. SQL>STARTUP; Switches roles between the primary and standby databases. Enabling fast-start failover and starting an observer process involves the following tasks. 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. The broker reinstates the database as a standby database of the same type as the former standby database of the new primary database. An existing connection which is already closed from the database side would throw an error. The guide makes few assumptions about your existing environment and includes examples for creating a physical standby database and Data Guard Broker configuration. Writing the wrapper itself and the means to determine when to execute it are up to you. POTENTIAL DATA LOSS: Fast-start failover is enabled with some data loss. Although redo transfer is synchronous, Maximum Availability mode allows the primary to remain available if the standby database becomes unavailable for any reason (e.g. Switch-over steps: Step-A: Shutdown primary database: SQL> shut immediate; Database closed. See Reenabling Disabled Databases After a Role Change. 2. directory by this environment variable does not exist, or the $DG_ADMIN 3. Set the ObserverPingInterval and command START OBSERVER IN BACKGROUND. This nomination is noted in the observer log file and in the broker log file (drc*.log). If the specified log file is not accessible, or the LOGFILE IS option is not used, then the observer output is sent to standard output. The following example shows you how to set up more than one service on a database and how using the broker ensures that the correct service starts on the correct database. After a complete failover finishes, any bystander standby database that is not viable as a standby for the new primary database will be disabled by the broker. this directory are used to store the files related to the If fast-start failover is For Oracle Database Release 12.2 and higher, Oracle Enterprise Manager Cloud Control (Cloud Control) supports configuring multiple observers using the Enterprise Manager Command Line Interface (EM CLI). environment that is guaranteed to either lose no data (when the See theFlashback Database section above for information on storage requirements. Alternatively, you can query the V$DATABASE view on the target standby database. Oracle Real Application Clusters Administration and Deployment Guide for more information about configuring FAN, FCF, and ONS on an Oracle Real Application Clusters (Oracle RAC) database. Use synonyms for the keyword you typed, for example, try "application" instead of "software.". 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. This action will result in loss of data and the possibility of two databases in the configuration simultaneously assuming the primary database role. Reinstatement will have to be accomplished by other means (manual or scripted Broker commands). Once an immediate failover is started, the broker: Verifies that the target standby database is enabled. Then, on the Fast-Start Failover Configure page, select the standby database that should be the target of a failover. Depending on the failover and the types of standby databases involved, some of the databases may need to be reinstated or re-created. 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. Example 6-2 Sample Observer Configuration File. If that metadata is pushed out, Oracle can no longer find a fuzzy snapshot so it will not be able to flash back. FastStartFailoverLagLimit property. You can use the SHOW CONFIGURATION WHEN PRIMARY IS command to show the redo transport configuration (based on each member's setting of the RedoRoutes property) that would be in effect if the specified database were the primary database. There are prerequisites that must be met before the broker allows you to enable fast-start failover. If a single-instance primary database (either Oracle RAC or non-Oracle RAC), or if all instances of an Oracle RAC primary database are shut down with the ABORT option, the observer attempts a fast-start failover. Execute the following on primary database NORTH: Execute the following on the physical standby database SOUTH: If the broker now performs a switchover or failover, it automatically starts the SALES service on the correct database, based on the database's role. During a switchover, the primary database transitions to a standby role, and the standby database transitions to the primary role. Overall Steps:-. With a value of TRUE for this property, the primary will shut down after being stalled for the number of seconds specified by the FastStartFailoverThreshold property.