RDF System Management Manual

Managing RDF
HP NonStop RDF System Management Manual—524388-003
5-15
Stopping RDF From the Primary System
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
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.
When you shut down RDF by issuing a TMFCOM STOP TMF command, you can use
successive STATUS RDF commands to determine when all of the RDF processes
have stopped.
Stopping RDF From the Primary System
When you issue the STOP RDF command on the primary system, all RDF processes
stop immediately without processing to the end-of-file mark in the MAT (except the
updaters, which may continue for a short while to finish up their work in progress).
While RDF is running, the database on the backup system is always in an inconsistent
state because updaters apply audit asynchronously with regard to one another. When
you stop RDF by issuing an STOP RDF command, you must stop the subsystem
wherever it currently is (which means that the database on the backup system is left in
an inconsistent state).
To leave the two databases logically identical, you must do the following before issuing
the STOP RDF command:
•
Issue a TMFCOM DISABLE BEGINTRANS command. This command prevents the
applications from initiating any new transactions until you issue a TMFCOM
ENABLE BEGINTRANS command.
•
Issue TMFCOM STATUS TRANSACTIONS commands and wait until the display
shows no transactions in progress.
Note. For this scenario to work, you must issue the STOP RDF command on both systems
before the communications lines come back up.
Caution. If the starting of new transactions is disabled, applications could abort unless they
have been coded to handle that situation.