RDF/IMP and IMPX System Management Manual (RDF 1.4+)

Managing RDF
HP NonStop RDF/IMP and IMPX System Management Manual—524388-001
5-12
Stopping RDF by Stopping TMF
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.
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.
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 can issue a STOP RDF
command. In this case, RDF stops processing without reading to the TMF
Note. If the extractor process falls way behind TMF because the communications lines 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.
Note. TMF does not start RDF, which means that if you start TMF, you must then explicitly
start RDF.