RDF System Management Manual

Entering RDFCOM Commands
HP NonStop RDF System Management Manual—524388-003
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Command Overview
For more information about undo processing during a takeover operation, see
Takeover Operations in section 5.
During a TAKEOVER operation, RDF completes all the processing it can on the
backup system, writes information about pending records (data audit records for which
no commit/abort records have been received on the backup system) to the exception
file, and stops RDF on the backup system. You should verify that the takeover was
completed successfully by checking the log for 724 or 725 messages. Message 724
indicates that the takeover completed successfully. Message 725 indicates that it did
not, and you should reissue the TAKEOVER command.
If a double CPU failure occurs and the receiver process pair or an updater process pair
fails during a takeover operation, you can resume the operation just by entering the
TAKEOVER command through RDFCOM again.
Regardless of whether the RDF monitor was started during execution of the previous
TAKEOVER command, it is started when this command is reissued.
It is conceivable that one or more transactions could get committed on the primary
database immediately prior to the TAKEOVER operation but that their commit records
did not reach the backup system before the primary system failure. If that happens,
the audit data for the affected transactions is not committed on the backup system and
is instead written to the exception file. In such a case, your database administrator
might be able to use RDFSNOOP to examine the affected data pointed to by the
exception file. For information about using RDFSNOOP, refer to Appendix B,
Additional Reference Information.
If the failed primary system is eventually restored to operation, and you want it to
function again as the primary system, do the following:
1. Stop the applications and TMF on the old backup system.
2. Back up the database on the old backup system and restore it to the old primary
system.
3. Configure TMF on the old primary system.
4. Initialize RDF on the old primary system.
5. Restart TMF on the old backup system.
6. Start the TMF and RDF subsystems on the old primary system.
7. Start the applications on the old primary system.
For further related considerations, see also Exception File Optimization in section 5.