Transaction Log Truncation

Replication Agent supports both automatic and manual log truncation.

Replication Agent provides two options for automatic transaction log truncation:

Periodic truncation, based on a time interval you specify
Automatic truncation whenever Replication Agent receives a new LTM locator value from the primary Replication ServerYou also have the option to switch off automatic log truncation. By default, automatic log truncation is switched off.

To configure Replication Agent log truncation, observe these guidelines:

You can specify the automatic truncation option you want (including none) by using ra_config to set the value of the truncation_type configuration parameter.

To truncate the transaction log automatically based on a time interval, use ra_config to set the value of the truncation_interval configuration parameter.
You can truncate the Replication Agent transaction log manually, at any time, by invoking pdb_truncate_xlog at the Replication Agent administration port.

To truncate the transaction log at a specific time, use a scheduler utility to execute the pdb_truncate_xlog command automatically.
Replication Agent for Microsoft SQL Server truncates the primary database log in units of transactions. After Replication Agent for Microsoft SQL Server receives the LTM locator from Replication Server, Replication Agent for Microsoft SQL Server queries the primary database to obtain the transaction ID of the newest transaction that can be truncated. Replication Agent for Microsoft SQL Server then marks as reusable the transaction log space before the newest transaction. Microsoft SQL Server can then write log records into the reusable space.
The sp_repltrans and sp_repldone Microsoft SQL Server commands are issued by Replication Agent to control log truncation within Microsoft SQL Server. These commands require that the Replication Agent user have the db_owner role permission.

Note: Microsoft SQL Server allows only one session to control log truncation using the sp_repltrans and sp_repldone commands. You should not use these commands while Replication Agent is controlling the log truncation processing.

For more information on these properties, see the Replication Agent Reference Manual. For a more detailed description of truncating, see "Administering Replication Agent” in the Replication Agent Administration Guide.