Start DPR Capture (STRDPRCAP)

The Start DPR Capture (STRDPRCAP) command starts the process that captures changes to iSeries data source tables.

The files that you want to capture changes for must first be registered.

You register files using the Replication Center or Add DPR Registration (ADDDPRREG) command. The files that you register for change capture are defined in the "CAPCTLLIB"/IBMSNAP_REGISTER table.

When you have registered the source tables to use remote journaling, you must run the STRDPRCAP command on the same system where you registered the source tables.

The values for the retention limit and the lag limit in the Tuning Parameter table IBMSNAP_CAPPARMS affect the operation of the STRDPRCAP command. You can alter these settings using the Change DPR Capture Attributes (CHGDPRCAPA) command. These values take affect when the Capture component is started. While capture is in active state you can change the capture tuning values dynamically using the Override DPR Capture Attributes OVRDPRCAPA command.

Note: Do not precede an entry with an asterisk unless that entry is shown on the display itself or in the help information with an asterisk.

Error Messages for STRDPRCAP

*ESCAPE Messages

ASN2002: Capture Parameters table not found.
ASN2003: No tables have been registered.
ASN2560: Capture instance is already active.
ASN2561: Capture instance is starting.
ASN2019: Not authorized to Capture Parameters table IBMSNAP_CAPPARMS.
ASN2501: Not authorized to register table.
ASN2513: STRDPRCAP command failed.
ASN4501: Register table not found or failed to open.

Parameters

Keyword	Description	Choices	Notes
RESTART	Restart after end	YES, NO	Optional, Positional 1
JOBD	Job description	Qualified object name	Optional, Positional 2
	Qualifier 1: Job description	Name, QZSNDPR
	Qualifier 2: Library	Name, *LIBL
WAIT	Wait	60-6000, 120	Optional, Positional 3
CLNUPITV	Clean up interval	Element list	Optional, Positional 4
	Element 1: Wait time	1-100, *DFT
	Element 2: Start clean up	IMMED, DELAYED, *NO
CAPCTLLIB	Capture control library	Name, ASN	Optional, Positional 5
JRN	Journal	Single values: ALL Other values (up to 50 repetitions): Qualified object name*	Optional
	Qualifier 1: Journal	Name
	Qualifier 2: Library	Name, LIBL, CURLIB
TRCLMT	Trace limit	1-35000000, *DFT	Optional
MONLMT	Monitor limit	1-35000000, *DFT	Optional
MONITV	Monitor interval	60-6000, *DFT	Optional
MEMLMT	Memory limit	1-35656, *DFT	Optional
RETAIN	Retention period	1-35000000, *DFT	Optional
LAG	Lag limit	1-35000000, *DFT	Optional
FRCFRQ	Force frequency	30-600, *DFT	Optional

Top

Restart after end (RESTART)

Specifies how to start the Capture process.

*YES: The Capture process continues processing the changes from the point that it finished when previously ended. Also known as a warm start , this is the default mode of operation.
*NO: The Capture process removes all information from the Change Data tables before it processes the changes. If you specify *ALL on the JRN parameter, Capture also removes all information from the "CAPCTLLIB"/IBMSNAP_UOW table. The subscriptions for all of the affected base tables are full-refreshed before change capture resumes. This is also known as a cold start .

Wait (WAIT)

Specify the maximum number of seconds to wait before the Capture process checks its status. You can use this value to tune the performance of the Capture process. A low value reduces the time the Capture process takes before ending or initializing, but can have an effect on system performance. A higher value increases the time the Capture process takes before ending or initializing, but can improve system performance. A value that is too high can result in decreased performance while the Capture process is performing periodic processing. The amount of the decrease in performance depends on the amount of change activity to registered files and the amount of other work occurring on the system.

120: The default maximum number of seconds the Capture process waits.
60-6000: Specify the maximum number of seconds you want the Capture process to wait.

Clean up interval (CLNUPITV)

Specify the maximum number of hours the Capture process waits before pruning old records from the Change Data tables and other control tables.

This parameter works in conjunction with the RETAIN parameter (in the case of CDs, the UOW, the SIGNAL table and the AUTHTKN table), the TRCLMT parameter(in the case of the CAPTRACE table) and the MONLMT parameter (in case of the CAPMON table). Whereas this parameter determines how frequent to prune and the three other parameters determine whether an old row is eligible for pruning.

STRDPRCAP command uses the values RETENTION_LIMIT,TRACE_LIMIT, MONITOR_LIMIT and PRUNE_INTERVAL stored in the CAPPARMS table if the user chooses the default for RETAIN, TRCLMT, MONLMT and CLNUPITV parameters,respectively. A user can supply a new value for these limits on the STRDPRCAP command. Or the user can alter their values at a later time using the OVRDPRCAPA command while capture is running.

At the time interval you specify on this parameter, the Capture process uses information from the Pruning Set table to determine which records in the Change Data tables are eligible for pruning.

This is a two-part value. The first part specifies the number of hours the Capture process waits before pruning records.

*DFT: Specifies that the default value is used for the CLNUPITV parameter. The default value is the value of the PRUNE_INTERVAL column of the Capture tuning parameters table ("CAPCTLLIB/IBMSNAP_CAPPARMS). You can change this value by changing the CLNUPITV parameter on the Change DPR Capture Attributes (CHGDPRCAPA) command.
24: The default maximum number of hours the Capture process waits.
1-100: Specify the maximum number of hours you want the Capture process to wait.

The second part specifies whether or not you want to prune records, or whether you want the Capture process to prune records immediately before capturing any changes.

*IMMED: The Capture process prunes old records from the Change Data tables before beginning to capture changes for the selected files.
*DELAYED: The Capture process waits the specified number of hours before pruning old records from the Change Data tables.
*NO: The Capture process does not prune records.

Journal (JRN)

Specify a list of up to 50 journals that you want the Capture process to work with. Capture will start processing all of the registered tables that are currently journaled to the specified journal or journals.

*ALL: Capture will start working with all of the journals that have any registered tables journaled to them.
library-name/journal-name: Specify the qualified name of the journal that you want the Capture process to work with.

Retention period (RETAIN)

Specifies the retention limit, which is the number of minutes that data is retained in the CD tables and the UOW table before it is removed.

The value of this parameter works with the CLNUPITV parameter. When the CLNUPITV value is reached, data in the CD and UOW tables is removed if the UOW table row shows that the transaction is older than the value of this parameter.

Ensure that the Apply intervals are set to copy changed information before the value on the RETAIN parameter is reached. This prevents your tables from becoming inconsistent. If they become inconsistent, the Apply program performs full refreshes.

*DFT: Uses the value from IBMSNAP_CAPPARMS.
retention-limit (in minutes): Specifies the number of minutes that the CD is retained.

Lag limit (LAG)

Specifies the lag limit, which is the number of minutes that the Capture program can fall behind before clearing out the CD tables and starting over with change capture. When the lag limit is reached (that is, when the timestamp of the journal entry is older than the current time minus the lag limit), the Capture program assumes that it is too far behind to catch up. It then initiates a cold start for the tables that it is processing for that journal. The Apply program then performs a full refresh to provide the Capture program with a new starting point. Users typically set this value high so that it has no effect.

*DFT: Uses the value from IBMSNAP_CAPPARMS.
lag-limit (in minutes): Specifies the number of minutes that the Capture processing of CD entries is allowed to fall behind.

Force frequency (FRCFRQ)

Specifies approximately how often the Capture program writes changes to the CD and UOW tables.

The Capture program makes the changes available to the Apply program either when the buffers are filled or when this time has expired, whichever occurs first.

Use this parameter to make source table changes more readily available for the Apply program on servers with a low rate of source table changes.

This is a global value, and is used for all defined source tables. Setting this value at a lower number can affect processor usage.

*DFT (default): Uses the COMMIT_INTERVAL value from IBMSNAP_CAPPARMS.
force-frequency (in seconds): Specifies the number of seconds that the Capture program keeps CD table and UOW table changes in buffer space before making them available for use by the Apply program. This value can range from 30 to 600 seconds.