RDF/IMP and IMPX System Management Manual (RDF 1.3+)

Managing RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
5-17
Initiating Takeover Operations
When the RDF subsystem #1 extractor starts sending current audit information to \A
(and at a convenient time with respect to your processing environment), stop
Applications #1 and carry out a planned switchover from \B to \A as follows:
1. On system \B, create an audited Enscribe file on each data volume in the RDF
subsystem #1 configuration.
2. Wait until all of those files are created on system \A.
3. On system \B, stop RDF subsystem #1.
4. Purge the Enscribe files on both systems.
5. On system \A, initialize RDF subsystem #1 using the INITTIME option and
specifying the current (for \A) local time.
6. On system \A, restart Applications #1.
Initiating Takeover Operations
If the primary system fails and you want to switch application processing to the backup
system, you need to issue the TAKEOVER command from the backup system. The
TAKEOVER command causes RDF to shut down after bringing the backup database to
a consistent state.
Preparing for Takeover Processing
Before you issue a TAKEOVER command from the backup system, you need to specify
the name of the control subvolume in the command that starts your RDFCOM session:
>RDFCOM control-subvol
Issuing the TAKEOVER Command
To request the takeover operation, enter the TAKEOVER command as follows:
]TAKEOVER
If the communications lines are up and the monitor and extractor are still running on the
primary system when you issue the TAKEOVER command, RDF rejects this command.
If the communications lines are down or the monitor and extractor have failed when you
issue the TAKEOVER command, RDF executes the command, as follows on the backup
system:
•
If RDF is running with updating on, RDFCOM sends a takeover message to the
receiver and all updater processes.
•
If RDF is running with updating off, RDFCOM stops the receiver process and starts
the monitor in takeover mode. The monitor then starts a receiver process and all
updater processes. (The name of this monitor on the backup system is generated by
the system.)