8 Oracle Data Guard Broker Properties

Use Oracle Data Guard broker properties to manage instances or the entire configuration.

Broker configuration and database properties help you to view and control the behavior of entire broker configurations, individual configuration members, redo transport services, and log apply services.

Properties have either configuration-wide scope, database-wide scope, far sync instance-wide scope, or instance-specific scope. Configuration-wide properties control the behavior of the broker on all members of the configuration. The values of such properties apply uniformly across all members of the configuration.

Database-wide properties allow you to view or control the behavior of a specific database. If the database (primary or standby) is an Oracle RAC database consisting of multiple instances, then the value of such a property applies uniformly across all instances of that database.

Far sync instance-wide properties allow you to view or control the behavior of a far sync instance.

Instance-specific properties allow you to view or control the behavior of an individual database instance. Such a property exists for all instances of an Oracle RAC database, but its value can differ from one specific instance to another.

Note:

You can use the Oracle Data Guard broker command-line interface (DGMGRL) to view or modify broker properties.

Oracle Enterprise Manager Cloud Control (Cloud Control) explicitly presents some broker properties on the Edit Properties page. Information from other properties can be implicitly incorporated into other Web pages displayed by Cloud Control. See the individual description of each property for information about how Cloud Control presents that property.

8.1 Configuration Properties

Configuration properties control the behavior of the broker configuration.

You can view and dynamically update the values of these properties using either DGMGRL or Cloud Control. However, some properties can only be updated through DGMGRL.

A configuration property has configuration-wide scope; meaning that the value you set for the property applies uniformly to each member in the configuration.

Configuration properties are set using the EDIT CONFIGURATION SET PROPERTY command, as shown in the following examples.

Example 1

This example sets the FastStartFailoverThreshold configuration property to 90 seconds.

DGMGRL> EDIT CONFIGURATION SET PROPERTY FastStartFailoverThreshold=90;

Example 2

This example sets the ExternalDestination1 configuration property to point to a redo transport destination with a service name of Sales and a DB_UNIQUE_NAME of chicago.

EDIT CONFIGURATION SET PROPERTY ExternalDestination1='SERVICE=Sales DB_UNIQUE_NAME=chicago';

Note:

In general, quotation marks are not necessary around property values unless the case you specify needs to be preserved. By default, DGMGRL lowercases any string you supply, unless it is placed within quotation marks.

Quotation marks are required for any property values that include spaces or punctuation characters (for example, RedoRoutes.

The following sections describe the configuration properties:

8.1.1 BystandersFollowRoleChange

The BystandersFollowRoleChange configuration property establishes whether bystander standby databases are evaluated during failover (value = ALL) or after failover (value = NONE).

Descriptions of the ALL and NONE options are as follows:

  • ALL - During the failover process, the broker determines whether the bystander standby databases are ahead of or behind the failover target standby (that is, the standby that will be the new primary).

    If the bystander standbys are ahead, they will be disabled with a status of ORA-16661 as part of the failover operation. The bystander standbys must be reinstated after failover completes. The broker reinstates a standby through a flashback to the SCN at which the target standby became a primary database, and sets up the redo transport configuration from the new primary to the standby.

    If the bystander standbys are behind, then the broker simply sets up the redo transport configuration from the soon-to-be-new-primary to these standbys and completes the failover process.

  • NONE - During the failover process, the broker does NOT evaluate the status of the bystander standbys as part of the failover operation. They are marked as disabled with a status of ORA-16661 so that they can be evaluated later. The broker simply completes the failover to produce a new primary database as soon as possible.

    After the failover is completed, you can reinstate the bystander standbys. During reinstatement of a bystander, the broker determines whether the bystander is ahead of, or behind, the new primary. If the bystander is ahead of the new primary, then the broker automatically flashes back the standby to the SCN at which the target standby became a primary database and sets up redo transport from the new primary to the standby. (Even if a flashback is not required, the broker sets up the redo transport configuration from the new primary to these standbys.)

    The NONE option decreases the processing time for failover, but disables broker management of all bystander databases in the configuration. If fast-start failover is enabled, then the observer automatically reinstates the standby databases after failover has completed. Otherwise, you will have to manually reinstate the standby databases after failover has completed.

Category Description

Datatype

String

Valid value

ALL or NONE

Broker default

ALL

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by broker on the database that is the target of a complete failover.

Cloud Control name

Not applicable

8.1.2 CommunicationTimeout

The CommunicationTimeout configuration property allows you to decide how many seconds the broker should wait before timing out its network communication between members in the configuration.

A value of zero indicates that a network communication should never be timed out.

Category Description

Datatype

Integer

Valid values

>= 0

Broker default

180 seconds

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by broker on all databases in the configuration.

Cloud Control name

Not applicable

8.1.3 ConfigurationSimpleName

The ConfigurationSimpleName configuration property is used to specify the directory that contains the observer runtime data file (fsfo.dat), observer log files, and callout configuration files that correspond to a specific broker configuration.

For databases that use versions lower than Oracle Database Release 21c, ConfigurationSimpleName cannot be explicitly set. This value is determined in real time, when the broker connects to the database, by combining the configuration name and the database's DB_UNIQUE_NAME (after removing any invalid characters).

The initial value of ConfigurationSimpleName is set using the following rules (in the order listed):

  • Broker configuration name, if the name is less than or equal to 30 characters and contains valid characters.
  • First 30 characters of the broker configuration name, if the name is more than 30 characters and the first 30 characters contain valid values.
  • DB_UNIQUE_NAME

This value is configurable and you can modify the initial value that is set.

Category Description
Datatype String
Valid values
  • The characters are limited to the following: [a...z], [A...Z], [0...9], _, #, and $.

  • The first character must be an alphanumeric character.

  • There is a 30–character maximum. The name is case-sensitive.

Broker default

If the configuration name contains 30 characters or less, and contains only the characters a-z or A-Z, numerals 0-9, or special characters _, #, $, the default value is the first 30 characters of configuration name.

If the configuration name is longer than 30 characters, and its first 30 characters contain only the characters a-z or A-Z, numberals 0-9, or special characters _, #, or $, the default value is the forat 30 characters of the configuration name.

If netiher of the above conditions is satisfied, the default value if the DB_UNIQUE_NAME of the primary database

Imported? No
Parameter class Not applicable
Role Primary and standby
Standby type Not applicable
Corresponds to Not applicable
Scope Configuration
Cloud Control name Yes

8.1.4 ConfigurationWideServiceName

The ConfigurationWideServiceName configuration property is used to change the name of the configuration-wide service.

The broker publishes a service on each member of a configuration with a unified service name. The default service name of this configuration-wide service is primarydbname_CFG, where the primary database name is appended with a suffix of _CFG. The service name does not change after a role transition.

Category Description
Datatype String
Valid values
  • The characters are limited to the following: [a...z], [A...Z], [0...9], and _

  • The first character must be an alphanumeric character.

  • There is a 30–character maximum.

Broker default primarydbname_CFG
Imported? No
Parameter class Not applicable
Role Primary and standby
Standby type Not applicable
Corresponds to Not applicable
Scope Configuration
Cloud Control name Not applicable

8.1.5 ExternalDestination1

The ExternalDestination1 configuration property is used to specify a redo transport destination that can receive redo data from the current primary database.

To set up transport of redo data to the specified destination, the broker uses the values specified for this parameter to define a LOG_ARCHIVE_DEST_n initialization parameter on the primary database. The broker also monitors the health of the transport to the specified destination.

After a role change, the broker automatically sets up a LOG_ARCHIVE_DEST_n initialization parameter on the new primary database to ship redo data to the specified destination.

Note:

The ExternalDestination1 property requires that the database unique name (DB_UNIQUE_NAME) be specified.
Category Description

Datatype

String

Valid values

Any LOG_ARCHIVE_DEST_n attributes, except the following:

  • ALTERNATE

  • GROUP

  • PRIORITY

  • VALID_FOR

See Oracle Data Guard Concepts and Administration for more information about the LOG_ARCHIVE_DEST_n parameter.

Broker default

Empty string

Imported?

No

Parameter class

Not applicable

Role

Primary

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Configuration

Cloud Control name

Not applicable

Note:

The Externaldestination1 configuration property is available only in Oracle Database 11g Release 2 (11.2.0.4) and in Oracle Database 12c Release 1 (12.1.0.2) and later.

8.1.6 ExternalDestination2

The ExternalDestination2 configuration property is used to specify a redo transport destination that can receive redo data from the current primary database.

To set up transport of redo data to the specified destination, the broker uses the values specified for this parameter to define a LOG_ARCHIVE_DEST_n initialization parameter on the primary database. The broker also monitors the health of the transport to the specified destination.

After a role change, the broker automatically sets up a LOG_ARCHIVE_DEST_n initialization parameter on the new primary database to ship redo data to the specified destination.

Note:

The ExternalDestination2 property requires that the database unique name (DB_UNIQUE_NAME) be specified.
Category Description

Datatype

String

Valid values

Any LOG_ARCHIVE_DEST_n attributes, except the following:

  • ALTERNATE

  • GROUP

  • PRIORITY

  • VALID_FOR

See Oracle Data Guard Concepts and Administration for more information about the LOG_ARCHIVE_DEST_n parameter.

Broker default

Empty string

Imported?

No

Parameter class

Not applicable

Role

Primary

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Configuration

Cloud Control name

Not applicable

Note:

The Externaldestination2 configuration property is available only in Oracle Database 11g Release 2 (11.2.0.4) and in Oracle Database 12c Release 1 (12.1.0.2) and later.

8.1.7 FastStartFailoverAutoReinstate

The FastStartFailoverAutoReinstate 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.

To prevent automatic reinstatement of the former primary database in these cases, set this configuration property to FALSE.

The broker never automatically reinstates the former primary database if a fast-start failover was initiated because a user configuration condition was detected or was requested by an application calling the DBMS_DG.INITIATE_FS_FAILOVER function.

Category Description

Datatype

Boolean

Valid value

TRUE or FALSE

Broker default

TRUE

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the observer after fast-start failover has been enabled.

Cloud Control name

Automatically Reinstate Primary

8.1.8 FastStartFailoverLagLimit

The FastStartFailoverLagLimit configuration property establishes an acceptable limit, in seconds, that the standby is allowed to fall behind the primary in terms of redo applied.

If the limit is reached, then a fast-start failover is not allowed. The lowest possible value is 5 seconds.

This property is used when fast-start failover is enabled and the configuration is operating in maximum performance mode.

Category Description

Datatype

Integer

Valid value

Integral number of seconds. Must be greater than, or equal to, 5.

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the primary database after fast-start failover has been enabled.

Cloud Control name

Lag Limit

8.1.9 FastStartFailoverPmyShutdown

The FastStartFailoverPmyShutdown configuration property causes the primary database to shut down under certain conditions.

The primary database shuts down if fast-start failover is enabled and V$DATABASE.FS_FAILOVER_STATUS indicates the primary has been STALLED for longer than FastStartFailoverThreshold seconds. In such a situation, it is likely that the primary has been isolated and a fast-start failover has already occurred. A value of TRUE helps to ensure that an isolated primary database cannot satisfy user queries.

Setting this property to FALSE will not prevent the primary database from shutting down if a fast-start failover occurred because a user configuration condition was detected or was requested by an application by calling the DBMS_DG.INITIATE_FS_FAILOVER function.

Category Description

Datatype

Boolean

Valid value

TRUE or FALSE

Broker default

TRUE

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the primary database after fast-start failover has been enabled.

Cloud Control name

Automatically Shutdown Primary

8.1.10 FastStartFailoverThreshold

The FastStartFailoverThreshold configuration property defines the number of seconds the master observer attempts to reconnect to the primary database before initiating a fast-start failover.

(If there is only one observer, then by default it is considered the master. The time interval starts when the observer first loses connection with the primary database. If the observer is unable to regain a connection to the primary database within the specified time, then the observer initiates a fast-start failover to the target standby database. See Task 4 in Enabling Fast-Start Failover for more information about setting this property.

The observer ignores the threshold completely if a configurable fast-start failover condition is detected or an application has requested that fast-start failover be initiated.

For help in determining an appropriate value for this property, you can use the information provided in the V$FS_OBSERVER_HISTOGRAM view. This view displays statistics that are based on the frequency of successful pings between the observer and primary database for different time intervals. (This view is available in Oracle Database 12c Release 1 (12.1.0.2) and later. It is also available in Oracle Database 11g Release 2 (11.2.0.4), but not in Oracle Database 12c Release 1 (12.1.0.1).) See Oracle Database Reference for a description of the V$FS_OBSERVER_HISTOGRAM view.

Category Description

Datatype

Integer

Valid value

Integral number of seconds. Must be greater than, or equal to, 6.

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Target standby database that is about to fail over to the primary role

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the observer after fast-start failover has been enabled.

Cloud Control name

Cloud Control presents this as "Failover Threshold" on the Oracle Data Guard Overview page.

8.1.11 ObserverOverride

The ObserverOverride configuration property, when set to TRUE, allows an automatic failover to occur when the observer has lost connectivity to the primary.

This is the behavior even if the standby has a healthy connection to the primary.

Category Description

Datatype

Boolean

Valid values

TRUE or FALSE

Broker default

FALSE

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the observer after fast-start failover has been enabled.

Cloud Control name

Not applicable

8.1.12 ObserverPingInterval

The ObserverPingInterval configuration property specifies how frequently the observer must ping the primary database.

This property is measured in milliseconds. The minimum value is 100 milliseconds. To achieve lower detection times for primary database failures, you must set the ObserverPingInterval and ObserverPingRetry properties before enabling fast-start failover.

The FastStartFailoverThreshold property is ignored when the ObserverPingRetry and ObserverPingInterval properties are set.

Category Description

Datatype

Integer

Valid values

>= 100

Broker default

100 milliseconds

Imported?

No

Parameter class

Not applicable

Role

Primary

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the observer after fast-start failover has been enabled.

Cloud Control name

Not applicable

8.1.13 ObserverPingRetry

The OberverPingRetry property specifies the number of times that the observer retries a failed ping before it initiates a failover to the target standby database.

A failed ping is a ping to the primary database that failed or took longer than the time specified by the ObserverPingInterval property. You must set both the ObserverPingRetry and ObserverPingInterval properties to achieve lower detection times for primary database failures. The minimum value of ObserverRetryCount is 10. Therefore, the detection time can be reduced to nearly 1 second.

The FastStartFailoverThreshold property is ignored when the ObserverPingRetry and ObserverPingInterval properties are set.

Category Description

Datatype

Number

Valid values

>=10

Broker default

10 milliseconds

Imported?

No

Parameter class

Not applicable

Role

Primary

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration

Cloud Control name

Not applicable

8.1.14 ObserverReconnect

The ObserverReconnect configuration property specifies how often the observer establishes a new connection to the primary database.

When this property is set to the default value of 0, the observer creates and maintains a connection to the primary database, but it does not periodically create a new connection to the primary database. While this eliminates the processing overhead associated with periodically establishing a new observer connection to the primary database, it also prevents the observer from detecting that it is not possible to create new connections to the primary database. Oracle recommends that this property be set to a value that is small enough to allow timely detection of faults at the primary database, but large enough to limit the overhead associated with periodic observer connections to an acceptable level.

Category Description

Datatype

Integer

Valid values

Integral number of seconds. Must be greater than, or equal to, 0.

Broker default

0

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by the observer after fast-start failover has been enabled.

Cloud Control name

Not applicable

8.1.15 OperationTimeout

The OperationTimeout configuration property specifies the maximum amount of time the broker should wait for health check, get monitorable property, and set property operations to complete.

Category Description

Datatype

Integer

Valid values

>= 30 and <= 3600

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration. This property will be consumed by broker on all databases in the configuration.

Cloud Control name

Not applicable

8.1.16 PreferredObserverHosts

The PreferredObserverHosts configurable property allows you to list the hosts that you would prefer as hosts for the master observer when that database is in the primary role.

The value of this property can be changed at any time, regardless of whether Fast-Start Failover is enabled or not, or whether the observer is in an OBSERVED state. However, the change does not affect the location of the master observer until the next role change.

If this property is set, then after a role change the broker takes the following steps:

  1. Checks whether the current master observer is running on a host in the list specified by the PreferredObserverHosts property of the new primary. If yes, stop here; otherwise, go to step 2.

  2. Scans the list from the beginning to look for a host where one observer is running, and connects to the primary and target standby databases. If found, go to step 3; otherwise, stop here.

  3. Attempts to switch the master observer to the host found in step 2. If switching fails, no other hosts are tried.

Category Description
Data type String
Valid value A character string that contains one or more host names, separated by comma:
host_name_1 [,host_name_n]

Each host name can be any character string for a valid network name, even if there is no observer running on this host when it is set.

Broker default Null
Imported? No
Parameter class Not applicable
Role Primary, standby
Standby type Physical standby and logical standby
Corresponds to Not applicable
Scope Database
Cloud Control name Not applicable

8.1.17 PrimaryLostWriteAction

The PrimaryLostWriteAction configuration property determines what action is taken if a primary or standby database detects that a lost write has occurred at the primary database.

Note:

The PrimaryLostWriteAction configuration property is available only in Oracle Database 11g Release 2 (11.2.0.4) and in Oracle Database 12c Release 1 (12.1.0.2) and later.

The possible actions are as follows:

  • CONTINUE - The primary database continues operating even if a primary or standby database detects that a lost write has occurred at the primary database. This is the default action.

  • SHUTDOWN - If a primary or standby database detects that a lost write has occurred at the primary database, then fast-start failover is disabled and the primary database performs a shutdown abort. Automatic failover will not occur.

  • FAILOVER - If fast-start failover is enabled in maximum performance mode, and the configuration is within the acceptable limit specified for the FastStartFailoverLagLimit property, then the observer initiates a failover.

  • FORCEFAILOVER - If fast-start failover is enabled (in either maximum performance or maximum availability mode), then the observer initiates a failover. This option results in a data loss failover.

For both the FAILOVER and FORCEFAILOVER options, if fast-start failover is disabled then no failover occurs, but the primary is shut down.

If a primary or standby database detects that a lost write has occurred at the primary database, fast-start failover is disabled if any of the following conditions are true:

  • PrimaryLostWriteAction is set to CONTINUE
  • PrimaryLostWriteAction is set to SHUTDOWN
  • PrimaryLostWriteAction is set to FAILOVER and protection mode is set to either maximum availability or maximum protection

Diagnostic information is written to the database alert and broker logs at the primary database and at the standby database where the lost write was detected.

If a lost write occurs at the primary database, then follow the guidelines in "Resolving ORA-752 or ORA-600 [3020] During Standby Recovery" in My Oracle Support Note 1265884.1 located at http://support.oracle.com.

Note:

The DB_LOST_WRITE_PROTECT database initialization parameter must be set to TYPICAL or FULL at the primary database and at each standby database in the configuration to ensure that lost primary writes can be detected by all standby databases in the configuration.

Category Description

Datatype

String

Valid values

CONTINUE, SHUTDOWN, FAILOVER, or FORCEFAILOVER

Broker default

CONTINUE

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Broker configuration

Cloud Control name

Not applicable

8.1.18 TraceLevel

The TraceLevel configuration property is used to control the amount of tracing performed by the broker for every member in the configuration.

Setting the property to USER limits the tracing to completed operations and to any warning or error messages resulting from an operation or health check. Setting the property to SUPPORT increases the amount of tracing to include lower-level information needed by Oracle Support Services.

Category Description

Datatype

String

Valid values

USER, SUPPORT

Broker default

USER

Imported?

No

Parameter class

Not applicable

Role

Primary and standby

Standby type

Not applicable

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Not applicable

8.2 Monitorable (Read-Only) Properties

Monitorable properties allow you to view information related to the database, database instance, or far sync instance.

You cannot change the values of monitorable properties. You can view all of them using the DGMGRL SHOW commands.

Note:

Information for monitorable properties can be seen only when broker management of the entity is enabled. Cloud Control displays the information obtained from these properties on the Property page.

If the database is an Oracle RAC database, the output values of some properties may also show instance-specific information. For example if the primary database is an Oracle RAC database, LogXptStatus may show Instance1 transmitting redo data to Standby2 has an error and Instance2 transmitting redo data to Standby4 has an error.

The following sections describe the monitorable properties:

8.2.1 InconsistentLogXptProps (Inconsistent Redo Transport Properties)

The InconsistentLogXptProps monitorable property returns a table that shows all properties related to redo transport services whose values are inconsistent between the broker configuration file and the runtime value.

Although the properties reported in this table are database-specific or far sync instance-specific properties, the inconsistency is reported on an instance-specific basis. A database or far sync instance-specific property only ensures that there is one value in the broker's configuration file for all instances of the database or far sync instance, but the runtime values can be different. This means that a database or far sync instance-specific property may be inconsistent only on some instances.

This property pertains to the primary database, a physical standby database that ships redo data, or a far sync instance. The table contains the following columns:

  • INSTANCE_NAME

    The value identifying the SID for the instance.

  • STANDBY_NAME

    The database unique name (DB_UNIQUE_NAME) of the standby database or far sync instance to which this redo transport services property pertains.

  • PROPERTY_NAME

    The name of the redo transport services property with an inconsistent value.

  • MEMORY_VALUE

    The runtime value being used in the database or far sync instance.

  • BROKER_VALUE

    The value of the redo transport services property saved in the broker configuration file.

8.2.2 InconsistentProperties (Inconsistent Properties)

The InconsistentProperties monitorable property shows all property values in the broker configuration file that are inconsistent with the values in the corresponding server parameter file or the runtime values.

Note:

The InconsistentProperties property is deprecated as of Oracle Database 19c and may be desupported in a future release. This property always has no value.

The information is shown in table format. Although the properties reported in this table are database-specific or far sync instance-specific properties, the inconsistency is reported on an instance-specific basis. A database or far sync instance-specific property only ensures that there is one value in the broker's configuration file for all instances of the database or far sync instance, but the runtime values can be different. This means that a database or far sync instance-specific property may be inconsistent only on some instances

Each individual configuration member has this property. The table contains the following columns:

  • INSTANCE_NAME

    The value identifying the SID for the instance.

  • PROPERTY_NAME

    The name of the property with the inconsistent value.

  • MEMORY_VALUE

    The corresponding runtime value being used.

  • SPFILE_VALUE

    The corresponding value saved in the server parameter file (SPFILE).

  • BROKER_VALUE

    The value of the property saved in the broker configuration file.

8.2.3 LogXptStatus (Redo Transport Status)

The LogXptStatus monitorable property returns a table that contains the error status of redo transport services for each of the enabled configuration members.

This property pertains to the primary database, a physical standby database that ships redo data, or a far sync instance.

The table contains the following columns:

  • PRIMARY_INSTANCE_NAME

    The value identifying the SID for the instance on the primary database.

  • STANDBY_DATABASE_NAME

    The database unique name (DB_UNIQUE_NAME) of the standby database or far sync instance.

  • ERROR

    The text of the redo transport error. If there is no error, the field is empty.

Each entry in the table indicates the status of redo transport services on one redo source to one redo destination.

The error status can be an empty string, which indicates there is no error.

In the following example, the STATUS from South_Sales is empty because there is no error for the South_Sales destination. The South_Report destination returned the ORA-01034 message.

DGMGRL> SHOW DATABASE 'North_Sales' 'LogXptStatus' ;
LOG TRANSPORT STATUS
PRIMARY_INSTANCE_NAME STANDBY_DATABASE_NAME               STATUS
         north_sales1          South_Sales
         north_sales1          South_Report    ORA-01034: ORACLE not available

8.2.4 LsbyFailedTxnInfo (Logical Standby Failed Transaction Information)

The LsbyFailedTxnInfo monitorable property identifies a failed transaction that caused log apply services to stop.

This property contains a string with the following values from the DBA_LOGSTDBY_EVENTS view:

  • XIDUSN: Transaction ID undo segment number

  • XIDSLT: Transaction ID slot number

  • XIDSQN: Transaction ID sequence number

  • STATUS_CODE: Status (or Oracle error code) belonging to the STATUS message

  • STATUS: Description of the current activity of the process or the reason why log apply services stopped

The transaction IDs and status information are separated by a string of number signs (###).

This property pertains to a logical standby database.

8.2.5 LsbyParameters (Logical Standby Parameters)

The LsbyParameters monitorable property contains a string that identifies the value of MAX_SGA and MAX_SERVERS specifically reserved for log apply services.

The MAX_SGA is the maximum system global area and MAX_SERVERS is the maximum number of parallel query servers. These values are separated by a string of number signs (###) in the LsbyParameters property.

This property pertains to a logical standby database.

Note:

As of Oracle Database Release 19c, the LsbyMaxEventsRecorded property is deprecated and may be desupported in a future release.

8.2.6 RecvQEntries (Receive Queue Entries)

The RecvQEntries monitorable property returns a table indicating all log files that were received by the standby database but have not yet been applied.

If no rows are returned, it implies all log files received have been applied. This property pertains to a standby database.

The table contains the following columns in the order shown:

  • STATUS

    The STATUS column is set to one of the following values for a log file on a logical standby database:

    • NOT_APPLIED: No redo records in this log file have been applied.

    • PARTIALLY_APPLIED: Some of the redo records in this log file have been applied while others have not.

    • COMMITTED_TRANSACTIONS_APPLIED: This status value only applies to a logical standby database. All redo records belonging to the committed transactions have been applied. Redo records belonging to uncommitted transactions have not been read by LogMiner and may still be needed when the transactions are committed in the future. Therefore, it is not safe yet to discard this online redo log file.

  • RESETLOGS_ID

    Resetlogs identifier associated with the archived redo log file

  • THREAD

    The redo thread number

  • LOG_SEQ

    The online redo log file sequence number

  • TIME_GENERATED

    The first time when the online redo log file was written to the primary database

  • TIME_COMPLETED

    The next time when the log file was archived on the primary database (corresponds to the NEXT_CHANGE# column)

  • FIRST_CHANGE#

    First change number in the archived redo log file

  • NEXT_CHANGE#

    First change in the next log file

  • SIZE (KBs)

    The SIZE of the online redo log file in kilobytes

For example:

DGMGRL> SHOW DATABASE 'South_Sales' 'RecvQEntries' ;
              STATUS     RESETLOGS_ID           THREAD
LOG_SEQ          TIME_GENERATED       TIME_COMPLETED    FIRST_CHANGE#
NEXT_CHANGE#        SIZE (KBs)
         NOT_APPLIED        497198843                1                    5
06/20/2003 14:55:38  06/20/2003 16:31:26           202138
210718             7364
         NOT_APPLIED        497198843                1                    6
06/20/2003 16:31:26  06/20/2003 16:31:39           210718
210753               13
         NOT_APPLIED        497198843                1                    7
06/20/2003 16:31:39  06/20/2003 16:31:54           210753
210758                1
         NOT_APPLIED        497198843                1                    8
06/20/2003 16:31:54  06/20/2003 16:31:59           210758
210789               11

Note:

Cloud Control displays this information on the Log File Details page.

8.2.7 SendQEntries (Send Queue Entries)

The SendQEntries monitorable property returns a table that shows all log files on the primary database that were not successfully archived to one or more standby databases.

This property pertains to the primary database.

The table contains the following columns:

  • STANDBY_NAME

    The value can be empty or it can contain the database unique name (DB_UNIQUE_NAME) of a standby database. If empty, the STATUS column will contain a value of CURRENT or NOT_ARCHIVED.

  • STATUS

    The STATUS column is set to one of the following values:

    • CURRENT: A log file to which online redo is currently being written.

    • NOT_ARCHIVED: A completed online redo log file that has not been archived locally.

    • ARCHIVED: A completed log file that has been archived locally but has not been transmitted to the standby database specified in the STANDBY_NAME column.

    The table contains exactly one row with the value of STATUS=CURRENT. There can be multiple rows with the value STATUS=ARCHIVED or STATUS=NOT_ARCHIVED.

  • RESETLOGS_ID

    Resetlogs identifier associated with the archived redo log file

  • THREAD

    The redo thread number.

  • LOG_SEQ

    The log sequence number. Multiple rows may have the same LOG_SEQ value (for different STANDBY_NAME values).

  • TIME_GENERATED

    The first time when the online redo log file was written to the primary database.

  • TIME_COMPLETED

    The next time when the log file was archived on the primary database (corresponds to the NEXT_CHANGE# column).

  • FIRST_CHANGE#

    First change number in the archived redo log file.

  • NEXT_CHANGE#

    First change in the next log file.

  • SIZE (KBs)

    The SIZE of the online redo log file in kilobytes.

For example, the following shows output from a SHOW DATABASE command:

DGMGRL> SHOW DATABASE 'North_Sales' 'SendQEntries' ;
PRIMARY_SEND_QUEUE
        STANDBY_NAME       STATUS     RESETLOGS_ID
THREAD              LOG_SEQ       TIME_GENERATED       TIME_COMPLETED
FIRST_CHANGE#     NEXT_CHANGE#       SIZE (KBs)
       South_Sales   ARCHIVED        497198843
1                    9  06/20/2003 16:31:59  06/20/2003 16:39:57
210789           211411              186
       South_Sales   ARCHIVED        497198843
1                   10  06/20/2003 16:39:57  06/20/2003 16:40:01
211411           211415                1
       South_Sales   ARCHIVED        497198843
1                   11  06/20/2003 16:40:01  06/20/2003 16:40:07
211415           211418                1
                          CURRENT        497198843
1                   12  06/20/2003 16:40:07
211418                                 1

Note:

Cloud Control displays this information on the Log File Details page.

8.2.8 TopWaitEvents

The TopWaitEvents monitorable property specifies the 5 events with the longest waiting time in the specified instance.

The events and their waiting time are retrieved from V$SYSTEM_EVENT. Each instance in the configuration has this property. This property is an instance-specific monitorable property. The table contains the following columns in the order shown:

  • Event

    The system wait event.

  • Wait Time

    The total amount of time waited for this event in hundredths of a second.

The following example shows output from a SHOW INSTANCE command:

DGMGRL> SHOW INSTANCE north_sales1 'TopWaitEvents';
TOP SYSTEM WAIT EVENTS
               Event            Wait Time
   rdbms ipc message               671350
SQL*Net message from client         62390
          pmon timer                47897
  Queue Monitor Wait                43016
 wakeup time manager                38508

8.3 Configurable Properties

Configurable properties control the behavior of broker configuration members.

You can view and dynamically update the values of these properties using either DGMGRL or Cloud Control. However, some properties can only be updated through DGMGRL.

These properties control certain database initialization parameters and SQL statements that the broker uses to manage an Oracle Data Guard broker configuration. Therefore, you should not manually set those initialization parameters or issue those SQL statements on a broker configuration.

In most cases, the configurable property is said to apply to the entire member, meaning the value you set for the property applies to each instance of the member (that is, database or far sync instance). However, in a few cases, the configurable property is said to have instance-specific scope which means that for a multiple-instance database or far sync instance, it is possible that the values of some particular properties may differ between instances. The following table lists each configurable property and indicates whether the scope of the property is member-wide or instance-specific. If the Scope column contains:

  • Member—The value of the property is database or far sync instance-wide, not instance or configuration specific.

  • Instance—The value of the property is instance specific.

    If there is an asterisk (*) present, it indicates that the property value can be set for all instances of an Oracle RAC database using the EDIT INSTANCE * ON DATABASE command.

  • Configuration—The value of the property is configuration wide, not instance or member specific.

Table 8-1 Configurable Properties

Configurable Property Name Scope Pertains To
AlternateLocation Member Redo transport services
ArchiveLocation Member Redo transport services
ApplyInstances Member Redo Apply

ApplyInstanceTimeout

Member

Redo Apply and SQL Apply

ApplyLagThreshold

Member

Redo transport services

ApplyParallel

Member

Redo Apply

Binding

Member

Redo transport services

DelayMins

Member

Redo Apply and SQL Apply

DGConnectIdentifier

Member

Broker communication, Redo transport services

Encryption Member Redo transport services

FastStartFailoverTarget

Member

Fast-start failover

InstanceName Instance Instance identification

LogShipping

Member

Redo transport services

LogXptMode

Member

Redo transport services

MaxFailure

Member

Redo transport services

NetTimeout

Member

Redo transport services

ObserverConnectIdentifier

Member

Fast-start failover

PreferredApplyInstance

Member

Redo Apply and SQL Apply

PreferredObserverHosts Member Fast-start failover

RedoCompression

Member

Redo transport services

RedoRoutes

Member

Redo transport services

ReopenSecs

Member

Redo transport services

StandbyAlternateLocation

Member

Redo transport services

StandbyArchiveLocation

Member

Redo transport services

StaticConnectIdentifier

Instance

Instance Startup and Shutdown

TransportDisconnectedThreshold

Member

Redo transport services

TransportLagThreshold

Member

Redo transport services

Note:

Starting with Oracle Database Release 19c, configurable properties that map directly to database initialization parameters and logical standby attributes are not maintained within the broker configuration file. See the "Deprecated Features" section in Changes in Oracle Database Release 21c for Oracle Data Guard Broker for a list of deprecated initialization parameters and logical standby attributes.

Note:

When a broker configuration with its primary database is created and members are added to the configuration, the broker imports existing settings from the members to set many of the properties. If importing an existing setting fails, or if a property value is not imported, then the broker uses a broker default value. The default values and whether or not a property is imported is indicated within each property description.

See Also:

Managing the Members of a Broker Configuration for more information about property management

Broker Controlled Database Initialization Parameters and SQL Statements

The following database initialization parameters are controlled by broker configurable properties. Therefore, you should not set these parameters manually:

  • LOG_ARCHIVE_DEST_n

  • LOG_ARCHIVE_DEST_STATE_n

The broker also uses configurable property settings to manage how apply is to be started. Therefore, the following SQL statements are managed automatically by the broker:

  • ALTER DATABASE RECOVER MANAGED STANDBY DATABASE

  • ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE

8.3.1 AlternateLocation

The AlternateLocation configurable property specifies an alternate online redo log archive location for primary, logical, and snapshot standby databases when the location specified by the ArchiveLocation configurable property fails.

If the StandbyArchiveLocation property is not empty, the AlternateLocation property specifies an alternate online redo log archive location. If the StandbyArchiveLocation property is empty, the AlternateLocation property specifies an alternate online and standby redo log archive location.

This property has database-specific scope, and the location that it specifies is applicable to all instances in a database.

Category Description
Datatype String
Valid values
  • An empty string when no alternate location is desired.

  • A directory specification that is accessible by the database.

  • A valid LOG_ARCHIVE_DEST_n parameter string with the LOCATION attribute specified, but no VALID_FOR, ALTERNATE, or SERVICE attributes.

Broker default Empty string
Imported? No
Parameter class Dynamic
Role Primary and standby
Standby type Physical, logical, or snapshot standby
Corresponds to On the primary or standby database, the LOCATION attribute for the LOG_ARCHIVE_DEST_n initialization parameter that represents an alternate destination of the local destination that matches the configurable property ArchiveLocation.
Scope Member
Cloud Control name There is no Cloud Control name

8.3.2 ArchiveLocation

The ArchiveLocation configurable property specifies the online redo log archive location for primary, logical, and snapshot standby databases.

If the StandbyArchiveLocation property is not empty, the ArchiveLocation property specifies an online redo log archive location. If the StandbyArchiveLocation property is empty, the ArchiveLocation property specifies an online and standby redo log archive location.

Set a value for this property if you want Oracle to manage local archiving.

Category Description
Datatype String
Valid values
  • An empty string when you do not want broker to manage the online archive location.
  • A nonempty file specification of the redo log archive location for the database. Specify USE_DB_RECOVERY_FILE_DEST if a database recovery area is desired.

  • A valid LOG_ARCHIVE_DEST_n parameter string with the LOCATION attribute specified, but no VALID_FOR, ALTERNATE, or SERVICE attributes.

Broker default Empty string
Imported? No
Parameter class Dynamic
Role Primary and standby
Standby type Physical, logical, or snapshot standby
Corresponds to
  • LOCATION attribute of the LOG_ARCHIVE_DEST_n initialization parameter of the primary or standby database with VALID_FOR compatible with (ONLINE_LOGFILE, ALL_ROLES)

  • DESTINATION column of the V$ARCHIVE_DEST view of the primary or standby database

Scope Member
Cloud Control name There is no Cloud Control name

8.3.3 ApplyInstances

The ApplyInstances property lets you specify how many physical standby instances run Redo Apply.

As of Oracle Database 12c Release 2 (12.2.0.1), a new INSTANCES keyword is available on the SQL ALTER RECOVER MANAGED STANDBY DATABASE statement (only for Oracle Real Application Clusters (Oracle RAC) or Oracle RAC One Node databases). When used, it causes Redo Apply to run on each active running physical standby instance that is running in the same mode as the instance on which Redo Apply was started. You can specify ALL or you can specify a specific number to restrict the number of instances that Redo Apply uses. If a database has already been set up to run Redo Apply on multiple instances, then you can use the Data Guard broker property ApplyInstances to restrict the number of instances that are involved in Redo Apply on an Oracle RAC physical standby database.

See Also:

Category Description
Datatype Integer
Valid values 0 to 16, ALL
  • ALL: indicates that redo apply will be started on all currently active instances

  • 0 and 1: recovery will be started in single instance mode.
  • >1: indicates that redo apply should not run on any more than the number of instances specified.
Broker default The default is 0.
Imported? Yes
Parameter class Not applicable
Role Standby
Standby type Physical standby
Corresponds to INSTANCES keyword of ALTER DATABASE RECOVER MANAGED STANDBY DATABASE command.
Scope Database
Cloud Control name Not applicable

8.3.4 ApplyInstanceTimeout

The ApplyInstanceTimeout configurable property specifies the number of seconds the broker waits after detecting the current apply instance failed before initiating the apply instance failover.

Category Description

Datatype

Integer

Valid values

>=0 (seconds)

Broker default

0 (results in immediate apply instance failover)

Imported?

No

Parameter class

Not applicable

Role

Standby, Recovery Appliance

Standby type

Physical, logical, Recovery Appliance

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Not applicable

8.3.5 ApplyLagThreshold

The ApplyLagThreshold configurable property generates a warning status for a logical or physical standby when the member's apply lag exceeds the value specified by the property.

The property value is expressed in seconds. A value of 0 seconds results in no warnings being generated when an apply lag exists.

Category Description

Datatype

Number

Valid values

>=0

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Standby, Recovery Appliance

Standby type

Physical, logical

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Not applicable

8.3.6 ApplyParallel

The ApplyParallel configurable property specifies whether Redo Apply should use multiple processes to apply redo data to the physical standby database.

If Redo Apply is shut off, then setting the property has no immediate effect. However, when Redo Apply is running again, the value of the property is used to determine the parallel apply behavior of Redo Apply.

Category Description

Datatype

String

Valid values

  • AUTO—the number of parallel processes used for Redo Apply is automatically determined by Oracle based on the number of CPUs that the system has.

  • NO—no parallel apply

  • 2, 3, and so on—manually specify the number of parallel processes used for Redo Apply. (Specifying 0 is the same as specifying NO; specifying 1 is the same as specifying AUTO.)

Broker default

AUTO

Imported?

No

Parameter class

Not applicable

Role

Standby

Standby type

Physical

Corresponds to

  • AUTO corresponds to the PARALLEL clause of the ALTER DATABASE RECOVER MANAGED STANDBY DATABASE statement

  • NO corresponds to the NOPARALLEL clause of the ALTER DATABASE RECOVER MANAGED STANDBY DATABASE statement

  • 2, 3, and so on corresponds to the PARALLEL n clause of the ALTER DATABASE RECOVER MANAGED STANDBY DATABASE statement

Scope

Database

Cloud Control name

Not applicable

8.3.7 Binding

The Binding configurable property specifies whether the destination is MANDATORY or OPTIONAL.

Category Description

Datatype

String

Valid values

  • MANDATORY

    You can specify a policy for reuse of online redo log files using the MANDATORY value. If the archiving operation of a mandatory destination fails, online redo log files cannot be overwritten.

  • OPTIONAL

    You can specify a policy for reuse of online redo log files using the OPTIONAL value. If the archiving operation of an optional destination fails, the online redo log files are overwritten.

Broker default

OPTIONAL

Imported?

No

Parameter class

Dynamic

Role

Standby database, Recovery Appliance, far sync instanceFoot 1

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

  • MANDATORY and OPTIONAL attributes for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • BINDING column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

Scope

Member

Cloud Control name

Not applicable

Footnote 1

Although this property is set for the redo destination, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.8 DelayMins

The DelayMins configurable property specifies the number of minutes log apply services will delay applying the archived redo log data on the standby database.

When the DelayMins property is set to the default value of 0 minutes, log apply services apply redo data as soon as possible.

If the DelayMins property is set to 0, start log apply services as follows:

  • Start Redo Apply on physical standby databases using the following SQL statement:

    ALTER DATABASE RECOVER MANAGED STANDBY DATABASE;
    
  • Start SQL Apply on logical standby databases using the following SQL statement:

    ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;
    
Category Description

Datatype

Integer

Valid values

>=0 (minutes) Foot 2

Broker default

0

Imported?

No

Parameter class

Dynamic

Role

StandbyFoot 3, Recovery Appliance

Standby type

Physical, logical, Recovery Appliance

Corresponds to

  • DELAY attribute for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • DELAY_MINS column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

  • Options used to start Redo Apply and SQL Apply

Scope

Database

Cloud Control name

Apply Delay (mins)

Footnote 2 The DelayMins property must be reset to 0 before attempting a switchover to a standby with DelayMins greater than 0.

Footnote 3

Although this property is set for the standby database, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify on the standby database to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.9 DGConnectIdentifier

The DGConnectIdentifier configurable property specifies the connection identifier the broker uses when making connections to a configuration member.

If you are using DGMGRL, then you supply the value when you enter the CREATE CONFIGURATION, ADD DATABASE, or ADD FAR_SYNC command. If you are using Cloud Control, the value is supplied automatically. The connect identifier for a configuration member must:

  • Allow all other members in the configuration to reach it.

  • Allow the member to reach itself.

  • Allow all instances of an Oracle RAC database to be reached.

  • Specify a service that all instances dynamically register with the listeners so that connect-time failover on an Oracle RAC database is possible.

    Caution:

    The service should NOT be one that is defined and managed by Oracle Clusterware.
  • Have failover attributes set to allow the primary database's Redo Transport Services to continue shipping redo data to an Oracle RAC standby database, even if the receiving instance of that standby database has failed.

The value of this property is specified in the SERVICE attribute of the LOG_ARCHIVE_DEST_n parameter when the broker configures redo transport services on the primary database.

Category Description

Datatype

String

Valid values

A connect identifier that can be used to connect to this database

Broker default

Not applicable

Imported?

No

Parameter class

Not applicable

Role

Primary, standby, far sync instance, Recovery Appliance

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

SERVICE_NAME attribute of the LOG_ARCHIVE_DEST_n initialization parameter of the configuration member that is sending redo data

Scope

Database, far sync instance, Recovery Appliance

Cloud Control name

Not applicable

8.3.10 Encryption

The Encryption configurable property is used to specify whether redo data is encrypted before transmitting it to a Recovery Appliance.

Note:

Redo transport encryption can only be used with a Recovery Appliance.
Category Description
Datatype String
Valid values DISABLE, ENABLE
  • When ENABLE is specified, the redo data is encrypted before it is sent to a Recovery Appliance.

  • When DISABLE is specified, the redo data is not encrypted before it is sent to a Recovery Appliance.

Broker Default DISABLE
Imported? No
Parameter class Dynamic
Role Recovery Appliance
Standby type Recovery Appliance
Corresponds to
  • ENCRYPTION attribute for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • ENCRYPTION column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data to the Recovery Appliance

Scope Recovery Appliance
Cloud Control name Not Applicable

8.3.11 FastStartFailoverTarget

The FastStartFailoverTarget configuration property specifies the DB_UNIQUE_NAME of one or more standby databases that can act as target databases in a fast-start failover situation when the database on which the property is set is the primary database.

These possible target databases are referred to as candidate fast-start failover targets. See Task 2 in Enabling Fast-Start Failover for more information about setting this property.

The FastStartFailoverTarget configuration property can only be set to the name of physical or logical standbys. It cannot be set to the name of a snapshot standby database, far sync instance, or Zero Data Loss Recovery Appliance.

Category Description

Datatype

String

Valid value

DB_UNIQUE_NAME of the database that is the target of the fast-start failover. You can specify names of multiple standbys or the keyword ANY. If multiple names are specified, then the broker selects them in the order in which they are listed. If the property is set to ANY, then the broker can select any one of all viable standbys of the primary as the current FSFO target.

Broker default

If only one physical or logical standby database exists, then the broker selects that as the default value for this property on the primary database when fast-start failover is enabled.

If more than one physical or logical standby database exists, then the broker selects one based on the order in which they are specified in the property definition. Targets are verified when fast-start failover is enabled.

For the target standby database, the broker automatically selects the current primary database as the value for this property when fast-start failover is enabled.

Imported?

No

Parameter class

Not applicable

Role

Primary or standby

Standby type

Physical or logical

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Cloud Control displays the value for the current primary database on the Oracle Data Guard Overview page, along with whether or not fast-start failover has been enabled.

8.3.12 InstanceName

The InstanceName configurable property corresponds to the INSTANCE_NAME initialization parameter.

The property can only be updated when broker management of the database is disabled. You should only update the value when the INSTANCE_NAME initialization parameter is changed. In such a case, you must disable broker management of the database, update the InstanceName property to match the new INSTANCE_NAME value, and then reenable broker management of the database.

Note:

If no existing instance in the broker configuration, for the database whose name matches this instance's db_unique_name, has an InstanceName property with a value that matches the INSTANCE_NAME initialization parameter for this instance, then the broker creates a new instance for this database that has this instance's db_unique_name.

Category Description

Datatype

String

Valid values

The value of the INSTANCE_NAME initialization parameter for this instance. On certain platforms, the value may be case-sensitive.

Broker default

Not applicable

Imported?

Yes

Parameter class

Not applicable

Role

Primary and standby

Standby type

Physical, logical, or snapshot

Corresponds to

INSTANCE_NAME initialization parameter

Scope

Instance

Cloud Control name

Not applicable

8.3.13 LogShipping

The broker uses the value of the LogShipping property when the primary database is in the TRANSPORT-ON state or when the physical standby or far sync instance forwards redo data to another member.

The other member can be a physical, logical, or snapshot standby, or a far sync instance.

  • If the primary database is in the TRANSPORT-ON state and the value of the LogShipping property is ON, then redo transport services are enabled to send redo data to the particular configuration member. If the LogShipping property is OFF, then redo transport services are disabled to that member.

  • If a configuration member that forwards redo data has its LogShipping property set to ON and the member to which it sends redo data also has its LogShipping property set to ON, then redo transport services are enabled from the member sending redo data to the member that is to receive redo data.

    If a member that forwards redo data has its LogShipping property set to ON but the member to which it sends redo data has its LogShipping property set to OFF, then redo transport services are disabled from the member sending redo data to the member that is to receive redo data.

Category Description

Datatype

String

Valid values

ON or OFF

Broker default

ON

Imported?

No

Parameter class

Dynamic

Role

Standby database, Recovery Appliance, far sync instanceFoot 4

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

ENABLE and DEFER values for the LOG_ARCHIVE_DEST_STATE_n initialization parameter of the database or far sync instance that is sending redo data

Scope

Database, Recovery Appliance

Cloud Control name

Log Shipping

Footnote 4

Although this property is set for a standby database or far sync instance, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify on the standby database to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.14 LogXptMode

The LogXptMode configurable property enables you to set the redo transport service.

You set the redo transport services on each configuration member to one of the following modes:

  • SYNC

    Configures redo transport services for this configuration member using the SYNC and AFFIRM attributes of the LOG_ARCHIVE_DEST_n initialization parameter. Standby redo log files are required. This mode is required for the maximum protection or maximum availability data protection modes. This redo transport service enables the highest grade of data protection to the primary database, but also incurs the highest performance impact.

  • ASYNC

    Configures redo transport services for this configuration member using the ASYNC and NOAFFIRM attributes of the LOG_ARCHIVE_DEST_n initialization parameter. Standby redo log files are required. This mode enables a moderate grade of data protection to the primary database, and incurs a lower performance impact than SYNC.

  • FASTSYNC

    Configures redo transport services for this configuration member using the SYNC and NOAFFIRM attributes of the LOG_ARCHIVE_DEST_n initialization parameter. This mode is only available in maximum availability protection mode. Because FASTSYNC transport mode uses the NOAFFIRM attribute of the LOG_ARCHIVE_DEST_n parameter, data loss is possible.

Category Description

Datatype

String

Valid values

SYNC, ASYNC, or FASTSYNC

Broker default

ASYNC

Imported?

No

Parameter class

Dynamic

Role

Standby database, Recovery Appliance, far sync instanceFoot 5

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

  • SYNC, ASYNC, AFFIRM, and NOAFFIRM attributes for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • ARCHIVER, TRANSMIT_MODE, and AFFIRM columns of V$ARCHIVE_DEST view of the database or far sync instance that is sendng redo data

Scope

Database, far sync instance, Recovery Appliance

Cloud Control name

Redo Transport Service

Footnote 5

Although this property is set for the standby database or far sync instance, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo. The broker propagates the setting you specify on the standby database or far sync instance to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data. Note that if a database receives redo from a database or far sync instance where the RedoRoutes property has been configured with a redo transport mode, then the mode specified by that RedoRoutes property value overrides the value of the LogXptMode property.

See Also:

Managing the Members of a Broker Configuration for more information about setting data protection modes for redo transport services

8.3.15 MaxFailure

The MaxFailure configurable property specifies the maximum number of contiguous archiving failures before the redo transport services stop trying to transport archived redo log files to the standby database.

A value of zero indicates that an unlimited number of failures are allowed.

Category Description

Datatype

Integer

Valid values

>=0

Broker default

If the standby database is part of a group as specified with the broker RedoRoutes property, then the default value 1. Otherwise, the default value is 0.

Imported?

No

Parameter class

Dynamic

Role

StandbyFoot 6, Recovery Appliance

Standby type

Physical, logical, snapshot, Recovery Appliance

Corresponds to

  • MAX_FAILURE attribute for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • MAX_FAILURE column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

Scope

Database, Recovery Appliance

Cloud Control name

Not applicable

Footnote 6

Although this property is set for a standby database or far sync instance, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify on the standby database or far sync instance to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.16 NetTimeout

The NetTimeout configurable property specifies the number of seconds the LGWR waits for Oracle Net Services to respond to a LGWR request.

It is used to bypass the long connection timeout in TCP.

Category Description

Datatype

Integer

Valid values

0 to 1200

Broker default

30

Imported?

No

Parameter class

Dynamic

Role

Primary, standby, far sync instance, Recovery Appliance

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

  • NET_TIMEOUT attribute of the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • NET_TIMEOUT column of V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

Scope

Database, far sync instance, Recovery Appliance

Cloud Control name

Not applicable

8.3.17 ObserverConnectIdentifier

The ObserverConnectIdentifier configurable property specifies a connect identifier that can be used by the observer to connect to this database.

The connect identifier can pertain only to the primary database, or to the target standby database when fast-start failover is enabled.

Category Description

Datatype

String

Valid Values

A connect identifier that observer can use to connect to this database

Broker Default

Empty StringFoot 7

Imported?

No

Parameter Class

Not applicable

Role

Primary and Standby

Standby Type

Physical or logical

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Observer Connect Identifier

Footnote 7

When this is Empty String (not set by the user), the connect identifier specified by this database's DGConnectIdentifier property will be used by the observer.

8.3.18 PreferredApplyInstance

The PreferredApplyInstance configurable property indicates that a particular instance is the preferred choice for serving log apply services.

It is only used when the database is a standby Oracle RAC database. The value could be an empty string (default) which means the broker chooses the apply instance.

Category Description

Datatype

String

Valid Values

The instance name (SID) or empty string. Note that on certain platforms, SIDs may be case-sensitive.

Broker Default

Empty string

Imported?

No

Parameter Class

Not applicable

Role

Standby, Recovery Appliance

Standby Type

Physical, logical, Recovery Appliance

Corresponds to

Not applicable

Scope

Database

Cloud Control name

Apply Instance

See Also:

8.3.19 PreferredObserverHosts

The PreferredObserverHosts configurable property allows you to list the hosts that you would prefer as hosts for the master observer when that database is in the primary role.

The value of this property can be changed at any time, regardless of whether Fast-Start Failover is enabled or not, or whether the observer is in an OBSERVED state. However, the change does not affect the location of the master observer until the next role change.

If this property is set, then after a role change the broker takes the following steps:

  1. Checks whether the current master observer is running on a host in the list specified by the PreferredObserverHosts property of the new primary. If yes, stop here; otherwise, go to step 2.

  2. Scans the list from the beginning to look for a host where one observer is running, and connects to the primary and target standby databases. If found, go to step 3; otherwise, stop here.

  3. Attempts to switch the master observer to the host found in step 2. If switching fails, no other hosts are tried.

Category Description
Data type String
Valid value A character string that contains one or more host names, separated by comma:
host_name_1 [,host_name_n]

Each host name can be any character string for a valid network name, even if there is no observer running on this host when it is set.

Broker default Null
Imported? No
Parameter class Not applicable
Role Primary, standby
Standby type Physical standby and logical standby
Corresponds to Not applicable
Scope Database
Cloud Control name Not applicable

8.3.20 RedoCompression

The RedoCompression configurable property is used to specify whether redo data is transmitted to a standby database or far sync instance in compressed or uncompressed form.

Note:

Redo transport compression is a feature of the Oracle Advanced Compression option. You must purchase a license for this option before using the redo transport compression feature.

Category Description

Datatype

String

Valid value

DISABLE ,ENABLE, ZLIB, or LZO
  • When ENABLE is specified, the default compression algorithm is ZLIB.

  • LZO is not supported when LogXptMode is set to SYNC or FASTSYNC.

Broker Default

DISABLE

Imported?

No

Parameter class

Dynamic

Role

Standby database, far sync instanceFoot 8, Recovery Appliance

Standby type

Physical, logical, or snapshot standby, far sync instance, Recovery Appliance

Corresponds to

  • COMPRESSION attribute for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • COMPRESSION column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

Scope

Database, far sync instance, Recovery Appliance

Cloud Control name

Not applicable

Footnote 8

Although this property is set for a standby database or far sync instance, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify on the standby database or far sync instance to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.21 RedoRoutes

The RedoRoutes property lets you override the default behavior by which a primary database sends the redo that it generates to every other redo transport destination in the configuration.

You can use the RedoRoutes property to create a more complex redo transport topology, such as one in which a physical standby database or a far sync instance forwards redo received from the primary database to one or more destinations, or one in which the redo transport mode used for a given destination is dependent on which database is in the primary role.

The RedoRoutes property is set to a character string that contains one or more redo routing rules. Each rule contains one or more redo sources and one or more redo destinations. A redo routing rule becomes active when one of the redo sources in the rule is in the primary role. This results in redo from the primary database being sent to every redo destination in that rule.

Category Description

Datatype

String

Valid values

A character string that contains one or more redo routing rules, each contained within a pair of parentheses:

(redo_routing_rule_1) [(redo_routing_rule_n)]

See "Redo Routing Rules" for more information about redo routing rules.

Broker default

Null

Imported?

No

Parameter class

Not applicable

Role

Primary, standby, far sync instance

Standby type

Physical standby and far sync instance

Corresponds to

LOG_ARCHIVE_DEST_n

Scope

Database, far sync instance

Cloud Control Name

RedoRoutes

8.3.21.1 Redo Routing Rules

The RedoRoutes property is set to a character string that contains one or more redo routing rules.

Each rule is contained within a set of parentheses, as follows:

(redo_routing_rule_1) [(redo_routing_rule_n)]

A redo routing rule contains a redo source field and a redo destination field separated by a colon:

(redo source : redo destination)

The redo source field must contain the keyword LOCAL or ANY, or a comma-separated list of DB_UNIQUE_NAME values, as follows:

{LOCAL | ANY | db_unique_name_1,[,db_unique_name_n]}
  • The LOCAL keyword is an alias for the local database name. This keyword cannot be used at a far sync instance.

  • The ANY keyword is an alias for any database in the configuration.

  • A database cannot be specified as a redo source in more than one redo routing rule defined at a given database, either explicitly or implicitly through use of the LOCAL keyword.

The redo destination field must contain the keyword ALL or a comma-separated list of redo destination groups, each of which consists of destination databases with optional priority attributes and optional redo transport mode attributes:

{ALL [xpt_mode] | redo_dest_group_1 [, redo_dest_group_n]}
  • The ALL keyword is an alias for all possible destinations in the configuration.

  • The redo_dest_group_n is:

    { db_unique_name_1 [xpt_mode] | ( db_unique_name_1 [xpt_mode] [PRIORITY=n] [,db_unique_name_n [xpt_mode] [PRIORITY=n]] ) }

    The optional xpt_mode specifies the redo transport mode to be used to send redo to the associated destination. It can have one of three values: ASYNC, SYNC, or FASTSYNC. If the redo transport attribute is not specified, then the transport mode used will be the one specified by the LogXptMode property for the redo destination.

    The optional [PRIORITY=n] can have n =1 ~ 8. The default value for far sync members is 1 and the default value for non-far sync members is 8. It is important to understand how different group and priority settings affect redo transport under various conditions. The following examples describe some sample situations.

Example 1: Different Priorities Within a Group

Assume there are three members in a broker configuration:
  • PRI (primary database)
  • SB1 (standby database)
  • FS1 (far sync instance)
The primary database PRI generates the redo log for use by the standby database SB1. Because there is a far sync instance, FS1, there are two possible redo delivery paths to the standby database:
  • (path 1) PRI —> FS1 —> SB1
  • (path 2) PRI —> SB1
Assume (path 1) is more desirable than (path 2). This can be expressed with the RedoRoutes property as follows:
  • PRIRedoRoutes = (local : ( FS1 PRIORITY=1, SB1 PRIORITY=2 ) )
  • FS1RedoRoutes = ( PRI : SB1 )

As specified in the PRI RedoRoutes property, the primary (PRI) has two destinations : one for FS1 with PRIORITY=1 and one for SB1 with PRIORITY=2. Smaller priority numbers mean higher priority, so primary PRI tries to ship the redo log to FS1 first.

If FS1 is available, then the primary ships to FS1 which has PRIORITY=1. If FS1 is unavailable, then the primary ships to SB1 which has PRIORITY=2. When FS1 becomes active again, the primary will ship to it again because priority 1 is higher than priority 2.

Example 2: The Same Priorities Within a Group

Suppose you add one more far sync instance, FS2, to the configuration set up in Example 1, and then update the RedoRoutes property as follows:
  • PRIRedoRoutes = (local : ( FS1 PRIORITY=1, FS2 PRIORITY=1 ) )
  • FS1RedoRoutes = ( PRI : SB1 )
  • FS2RedoRoutes = ( PRI : SB1 )

The primary PRI now has two destinations, FS1 and FS2, with the same priority. The primary must choose either FS1 or FS2. Assume the primary chooses FS1.

If FS1 is available, then the primary ships to FS1. If FS1 is unavailable, then the primary ships to FS2. Even after FS1 becomes active again, the primary continues shipping to FS2 because FS1 and FS2 have the same priority. If FS2 fails, then the primary ships to FS1.

Example 3: Multiple Groups

Assume that you add one more standby, SB2, to the configuration, and then update the RedoRoutes property as follows so that the primary has two destination groups:
  • PRIRedoRoutes = (local : ( FS1 PRIORITY=1, SB1 PRIORITY=2 ), ( FS2 PRIORITY=1, SB2 PRIORITY=2 ) )
  • FS1RedoRoutes = ( PRI : SB1 )
  • FS2RedoRoutes = ( PRI : SB2 )

The general rule is that there is one active redo path for each group. (See Example 4 for a scenario in which there are multiple active redo paths.) The primary establishes one redo delivery path for the first group ( FS1 PRIORITY=1, SB1 PRIORITY=2 ), and establishes another redo delivery path for the second group ( FS2 PRIORITY=1, SB2 PRIORITY=2 ).

  • If both FS1 and FS2 are available, then the primary ships to FS1 and FS2.

  • If FS1 is unavailable and FS2 is available, then the primary ships to SB1 and FS2.

  • If FS1 is available and FS2 is unavailable, then the primary ships to FS1 and SB2.

  • If both FS1 and FS2 are unavailable, then the primary ships to SB1 and SB2.

Example 4: The PRIORITY Attribute is Set to 8

Setting PRIORITY=8 has special meaning. If a primary ships redo to a destination with PRIORITY=8, then it must ship to every PRIORITY=8 destination. Suppose you update the RedoRoutes property as follows so that the primary has one group containing three destinations:
  • PRIRedoRoutes = (local : ( FS1 PRIORITY=1, SB1 PRIORITY=8, SB2 PRIORITY=8 ) )
  • FS1RedoRoutes = ( PRI : SB1, SB2 )

These settings result in the following behavior:

  • If FS1 is available, then the primary ships to FS1.

  • If FS1 is unavailable, then the primary ships to both SB1 and SB2 because they both have PRIORITY=8

  • If FS1 becomes active again, then the primary ships to FS1.

Usage Notes for Advanced Redo Transport Settings

The following usage notes apply regarding advanced redo transport settings:

  • The RedoRoutes property has a default value of NULL, which is treated as (LOCAL : ALL) at a primary database.

  • A redo routing rule is active if its redo source field specifies the current primary database. If a rule is active, primary database redo is sent by the database at which the rule is defined to each destination specified in the redo destination field of that rule.

  • The ASYNC redo transport attribute must be explicitly specified for a cascaded destination to enable real-time cascading to that destination.

  • The RedoRoutes property cannot be configured such that when a physical standby database is converted to a snapshot standby, the snapshot standby would send redo data to another member.

  • The RedoRoutes property can be set for a logical standby database only if the redo source field is set to LOCAL.

8.3.22 ReopenSecs

The ReopenSecs configurable property specifies the minimum number of seconds before the archiver process (ARCn, foreground, or log writer process) should try again to access a previously failed destination.

Category Description

Datatype

Integer

Valid values

>=0 seconds

Broker default

300

Imported?

No

Parameter class

Dynamic

Role

Standby database, far sync instanceFoot 9, Recovery Appliance

Standby type

Physical, logical, snapshot standby, far sync instance, Recovery Appliance

Corresponds to

  • REOPEN attribute for the LOG_ARCHIVE_DEST_n initialization parameter of the database or far sync instance that is sending redo data

  • REOPEN_SECS column of the V$ARCHIVE_DEST view of the database or far sync instance that is sending redo data

Scope

Database, far sync instance, Recovery Appliance

Cloud Control name

Not applicable

Footnote 9

Although this property is set for a standby database or far sync instance, it is indirectly related to the redo transport services for the database or far sync instance that is sending redo data. The broker propagates the setting you specify on the standby database or far sync instance to the corresponding attributes of the LOG_ARCHIVE_DEST_n value of the database or far sync instance that is sending redo data.

8.3.23 StandbyAlternateLocation

The StandbyAlternateLocation configurable property specifies an alternate standby redo log archive location to use when the location specified by the StandbyArchiveLocation configurable property fails.

The property has database-specific scope, and the location that it specifies is applicable to all instances in a database.

Category Description

Datatype

String

Valid values

  • An empty string, when no alternate location is desired.

  • A directory specification that is accessible by the instance.
  • A valid LOG_ARCHIVE_DEST_n parameter string with the LOCATION attribute specified, but no VALID_FOR, ALTERNATE, or SERVICE attributes.

Broker default

Empty string

Imported?

No

Parameter class

Dynamic

Role

Primary, standby, and far sync instance

Standby type

Physical, logical, or snapshot standby, or a far sync instance

Corresponds to

On the standby database or the far sync instance, the LOCATION attribute for the LOG_ARCHIVE_DEST_n initialization parameter that represents an alternate destination of the local destination that matches the configurable property StandbyArchiveLocation.

Scope

Member

Cloud Control name

Alternate Standby Location

Note:

On a logical standby database, Oracle recommends the LOCATION attribute of the LOG_ARCHIVE_DEST_n initialization parameter for the local destination be different from the value of StandbyAlternateLocation configurable property.

8.3.24 StandbyArchiveLocation

The StandbyArchiveLocation configurable property specifies the standby redo log archive location. Oracle recommends that you always explicitly set the value.

Category Description

Datatype

String

Valid values

  • An empty string when you do not want broker to manage the standby redo log archive location.

  • A nonempty file specification of the standby redo log archive location for the instance. Specify USE_DB_RECOVERY_FILE_DEST if a database recovery area is desired.

  • A valid LOG_ARCHIVE_DEST_n parameter string with the LOCATION attribute specified, but no VALID_FOR, ALTERNATE, or SERVICE attributes.

Broker default

Empty string

Imported?

No

Parameter class

Dynamic

Role

Primary, standby, and far sync instance

Standby type

Physical, logical, or snapshot standby, or a far sync instance

Corresponds to

  • LOCATION attribute of the LOG_ARCHIVE_DEST_n initialization parameter of the standby database or far sync instance with VALID_FOR compatible with (STANDBY_LOGFILE, ALL_ROLES)

  • DESTINATION column of the V$ARCHIVE_DEST view of the standby database

Scope

Member

Cloud Control name

Standby Archive Location

Note:

On a logical standby database, Oracle recommends the LOCATION attribute of the LOG_ARCHIVE_DEST_n initialization parameter for the local destination be different from the value of StandbyArchiveLocation property, unless you are using a database recovery area.

8.3.25 StaticConnectIdentifier

The StaticConnectIdentifier configurable instance-specific property specifies the connection identifier that the DGMGRL client will use when starting database instances.

If this property has a null value, then the DGConnectIdentifier value is used for operations that involve shutting down and starting up the instance.

Category Description

Datatype

String

Valid values

A connect identifier that refers to a service that is statically registered.

Broker default

Connect descriptor that is the concatenation of:Foot 10

  • The ADDRESS attribute value of the listener that is specified for the LOCAL_LISTENER initialization parameter

  • The value for the SERVICE_NAME attribute will be set to a concatenation of db_unique_name_DGMGRL.db_domain

Imported?

Yes, from the LOCAL_LISTENER and DB_UNIQUE_NAME initialization parameters.

Parameter class

Not applicable

Role

Primary and standby

Standby type

Physical, logical, or snapshot

Corresponds to

Not applicable

Scope

Instance

Cloud Control name

Not applicable

Footnote 10

If the instance specified by the InstanceName property is started with a different SID (read from the INSTANCE_NAME column of the V$INSTANCE view) than the SID with which it was previously started and/or it is started on a different host (read from the HOST_NAME column of the V$INSTANCE view) than the host on which it was previously started, then the broker automatically updates the default value of the StaticConnectIdentifier property to incorporate the current ADDRESS attribute of the listener that is specified for the LOCAL_LISTENER initialization parameter.

See Also:

8.3.26 TransportDisconnectedThreshold

The TransportDisconnectedThreshold configurable property can be used to generate a warning status for a logical, physical, or snapshot standby, or a far sync instance when the last communication from the primary database exceeds the property value.

The property value is expressed in seconds. A value of 0 seconds results in no warnings being generated.

Category Description

Datatype

Number

Valid values

>=0

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Standby database, far sync instance

Standby type

Physical, logical, or snapshot standby, or a far sync instance

Corresponds to

Not applicable

Scope

Database, far sync instance

Cloud Control name

Not applicable

8.3.27 TransportLagThreshold

The TransportLagThreshold configurable property can be used to generate a warning status for a logical, physical, or snapshot standby, or a far sync instance when the member's transport lag exceeds the property value.

The property value is expressed in seconds. A value of 0 seconds results in no warnings being generated when a transport lag exists.

Category Description

Datatype

Number

Valid values

>=0

Broker default

30 seconds

Imported?

No

Parameter class

Not applicable

Role

Standby database, far sync instance

Standby type

Physical, logical, or snapshot standby, or a far sync instance

Corresponds to

Not applicable

Scope

Database, far sync instance

Cloud Control name

Not applicable