StarQuest Technical Documents

Best Practices for Restoring or Migrating a Database Monitored by SQDR Plus for iSeries

Last Update: 28 April 2008
Product: SQDR Plus for iSeries
Version: 3.0 or later
Article ID: SQV00PL003

Abstract

Restoring or migrating a database that is currently being monitored by SQDR Plus may result in higher than normal CPU usage on the iSeries system. The high CPU usage results from the journal receiver processing that must occur after the database is restored.

This document describes a technique that will help minimize the processing required after restoring or migrating a database that is being monitored by SQDR Plus. The procedures described below cause SQDR to run baseline replications of all the incremental replication subscriptions instead of processing all the journal receivers produced by the restore operation. This is much more efficient than allowing incremental replication changes to be applied after the entire database is replaced and will result in much less CPU utilization.

Solution

Prior to restoring the database on the iSeries:

  1. Using the SQDR Replication Manager on the Windows system running SQDR, pause the Incremental Replication Group(s) by right-clicking the Group(s) and selecting Pause. Alternatively, you may stop the SQDR service from the SQDR Replication Manager or from Windows Services.
  2. On the iSeries, stop the SQDR subsystem using the OS400 command:

    ENDSBS SBS(SQDR) OPTION(*CNTRLD)

  3. Using either iSeries Navigator or an interactive SQL session (STRSQL), execute the following SQL statement.

DELETE FROM SQDR.SQ_READERS

Note: if executing the SQL statement using an interactive SQL session (STRSQL) set to the “*SYS” style naming convention, execute the following statement instead:

DELETE FROM SQDR/SQ_READERS

After restoring the database on the iSeries:

  1. On the iSeries, start the SQDR subsystem using the OS400 command:

    STRSBS SBSD(SQDR/SQDR)

  2. If you chose to stop the SQDR Service on the Windows system in Step 1, restart it. If you Paused the Incremental Replication Groups in Step 1, resume them by right-clicking the Group(s) and selecting Resume.

DISCLAIMER

The information in technical documents comes without any warranty or applicability for a specific purpose. The author(s) or distributor(s) will not accept responsibility for any damage incurred directly or indirectly through use of the information contained in these documents. The instructions may need to be modified to be appropriate for the hardware and software that has been installed and configured within a particular organization.  The information in technical documents should be considered only as an example and may include information from various sources, including IBM, Microsoft, and other organizations.