RDF System Management Manual for J-series and H-series RVUs (RDF 1.10)

>RDFCOM DALLAS3; STOP RDF
An alternative way to stop RDF on the backup system is to enter the following command through
TACL:
>STATUS *, PROG RDF-software-loc.*, STOP
CAUTION: Issuing this command in this situation is only safe, however, if this is the backup system
for a single RDF environment.
Stopping RDF Using STOP RDF, DRAIN
As stated above, stopping TMF shuts down RDF and it guarantees that the backup database is
then logically identical to the primary database. If, however, you have several different applications
running on your primary system, each working on its own database, and if not all are protected
by the one RDF subsystem, then you may not want to stop TMF just to shutdown the RDF subsystem.
In this situation, you can use the STOP RDF, DRAIN command, but you must observe the following
sequence of steps.
1. Stop the application that is updating your RDF-protected database.
2. Enter the STOP RDF, DRAIN command.
In response to the DRAIN command, the extractor marks its location in the audit trail when it receives
notice of the operation, and the updaters do not shut down until they have processed all audit up
to that location. Finally, the purger process generates RDF event 852 to notify you that the operation
has completed. Since your application has previously stopped, your backup database is now
logically identical to your primary database that is protected by this RDF subsystem, and you have
not had to stop TMF to get into this state. When you are ready to restart RDF, just enter the START
RDF command and it will resume where it left off last.
CAUTION: If you do not stop the application that is updating your RDF protected database until
after you have issued the STOP RDF, DRAIN command, then the backup database has low
probability of being logically identical to the primary database after RDF shuts down. If this happens
and the application is still down, then just restart RDF and then enter a new STOP RDF, DRAIN
command after the Extractor shows an RTD time of 0:00.
Stopping RDF using STOP RDF, REVERSE Operation
This operation is only useful for the special situation involving a switchover operation. See the
section on STOP RDF, REVERSE and the Reverse Trigger further below for a description of when
you would use this operation.
Restarting RDF
If you want to restart RDF and have it resume processing where it stopped at the previous shutdown,
you can only do so if you have not reinitialized RDF subsystem since the shutdown.
Use the START RDF command to restart RDF. RDF automatically starts with UPDATE ON unless you
explicitly specify UPDATE OFF in the START RDF command.
When RDF restarts, it uses the information in the context files to determine where it last stopped,
and resumes processing from that point.
NOTE: If you delete and reconfigure TMF, then you must initialize RDF.
Carrying Out a Planned Switchover
Many businesses run online transaction processing (OLTP) twenty-four hours a day. Stopping
applications to perform software or hardware upgrades, repairs, or other maintenance can result
in complications and inconvenience for system users. To minimize such planned outages, you can
Restarting RDF 127