Stopping Rdf By Stopping Tmf - HP NonStop RDF J-series RVUs Management Manual

enables the RDF processes to resume processing where they stopped before the shutdown, unless
an audit trail file that RDF needs has been purged and cannot be restored to disk.

Stopping RDF by Stopping TMF

The reason for stopping RDF by stopping TMF is to ensure that the primary and backup databases
are logically identical when the shutdown is complete (RDF has applied all changes to the backup
database). That will be the case, of course, only if all the updater processes stopped at the
shutdown record (if an updater experiences a double CPU failure, the databases will not be
identical). The disadvantage of this approach is that all applications on the primary system that
use TMF must be stopped also.
Stopping TMF also automatically unpins all audit trail files that were pinned on behalf of RDF.
When you issue a TMFCOM STOP TMF command, the following events occur:
1. TMF writes a shutdown record to the MAT. When the master extractor reads the shutdown
record, it notifies the monitor that TMF has stopped.
NOTE:
to the backup system have been down and come up again, it can take some time for the
extractor to get to the TMF shutdown record. The extractor stops processing the audit trail
files when it cannot communicate with the receiver and resumes processing when the
communications lines are restored.
2. The master extractor stops as soon as the master receiver replies that it has processed the
TMF shutdown record.
3. The RDFNET process (if there is an RDF network) does not wait for any other process to
stop; it merely stops when informed to do so.
4. If updating is enabled, each updater process stops when it reaches the TMF shutdown record
in its image trail.
5. The purger stops after all the updaters have stopped.
6. The receiver(s) stop when the purger has stopped.
7. The monitor stops after all the other RDF processes have stopped.
If you stop TMF and then restart it before RDF can read the shutdown record, RDF stops when
it encounters the shutdown record. If that happens, you need to issue a START RDF command
to restart RDF.
NOTE: TMF does not start RDF, which means that if you start TMF, you must then explicitly
start RDF.
If the communications lines are down when you stop TMF, the extractor continues to run, but
it will not recognize that TMF is shut down because the extractor does not read the data in the
MAT until the extractor can transmit data to the receiver on the backup system. If the extractor
is not reading the MAT, it cannot encounter the TMF shutdown message. Two situations could
arise:
• If the communications lines come back up before you restart TMF, RDF encounters the
TMFCOM STOP TMF record in the MAT and then stops processing.
• If the communications lines are down and you feel you really must stop the RDF system
irrespective of the TMF shutdown record, you must issue the STOP RDF command on both
the primary and backup systems. In this case, RDF stops processing without reading to the
TMF shutdown record in the MAT.
When you restart TMF, you must then restart RDF. RDF begins processing at the point where
it stopped. When RDF reads the TMF shutdown record associated with the preceding TMF
shutdown, RDF shuts down. You must then restart RDF again by issuing another START
RDF command.
If the extractor process falls way behind TMF because the communications lines
Stopping RDF 133