Once SQL Server standby database is created, you can control its synchronization with primary database through the automated standby update feature. You are also able to control whether Dbvisit will leave log backup copies on primary and you can also set Delay for transaction log apply to standby database.

1. Scheduling Automated Standby update (ASU)

Automated standby update (ASU) is an automated background process for synchronizing your standby database with primary. The ASU utilizes the backup folder which is by default C:\Program Files\Dbvisit\standbymp\backup on primary and standby. ASU is defined by interval, in which Dbvisit performs log backups on primary and ships them to standby. On standby this log backup is the automatically applied.

You can see whether the ASU is active for specific configuration by looking at the dbvcontrol dashboard:

Mouseover on the clock icon provides information about the ASU (1) and you are able to view the current gap between primary and standby database (2).

ASU can be enabled, disabled and interval modified by following option in ACTIONS pane:

The following form provide easy interface for modifying all of the options:

You can enable or disable the ASU (1) and modify the interval (2). Do not forget to click on Set button (3) in order to save any modifications you made.

2. Viewing and modifying Log Backup Synchronization Directory

The ASU utilizes the backup folder which is by default C:\Program Files\Dbvisit\standbymp\backup on primary and standby. By default, log backups are deleted as soon as they are transferred or applied.

You can view or modify this folder by going to “Backup Locations” option in the ACTIONS pane:

You can easily view or modify the locations on the following page:

You can define separate locations for primary (1) and standby (2). You can also modify directory for READ ONLY mode (3). READ ONLY mode for standby database is discussed more in detail here: SQL Server Standby Read Only Mode

Don’t forget to save changes (4).

3. Enabling Backup Log Retention On Primary

By default, Dbvisit StandbyMP doesn’t maintain any log backup copies on primary server once they were shippied to standby. It is possible however to configure such behavior in case you would like to use your own software to additionally backup the transaction log backups created by Dbvisit StandbyMP.

To enable the retention, select Log Backup Retention from ACTIONS pane:

You can afterwards configure to leave log backups on primary and/or standby once they were transferred/applied:

You are able to enable the retention on primary and standby server separately (1,2) and choose the amount of hours (3,4) after which the log backups will be deleted. Don’t foget to save any changes you made (5).

4. Standby Update Delay

You can define Standby Update delay for your standby database. Enabling this option will still make the transfer to happen immediately from primary, only the apply part will be delayed. To enable the standby update delay, choose following option from ACTIONS pane:

You can the specify the time period in minutes (1) for which the log backups will remain unapplied:

click on set (2) to save the changes. There is no hardcoded lower limit. But you should always aim for reasonable delay length. Set the Delay log application window to give you comfortable amout of time for:

• detecting that there was harmful change applied to primary

• making decision to stop the sycnhronization

• stopping automated standby update (ASU)

Any value less than 30-60 minutes makes will very likely make no sense and will be useless.

5. Manual Transfer and Apply of the log backups

This task is very useful when in doubt about synchronization status and for testing that individual ASU synchronization jobs work without any issues.

manual transfer and apply tasks described in this section are entirely the same tasks as performed by ASU.

A. Creating and Transferring Log Backup from primary

Backup & Transfer can be initiated from the ACTIONS pane:

Click on start on following screen:

New job is created in task bar and should complete successfully:

You will be able to view job details:

B. Applying Transferred Log Backup on standby

Apply of single transaction log can be initiated from ACTIONS pane as well:

Once you click on “start”, as with transfer, there will be an apply job and you can also check its details: