RDF System Management Manual for H-Series RVUs (RDF 1.8)

The planned switchover repeats the procedure described above, except that you reverse the roles
of systems \A and \B. After doing so, RDF replication once again occurs from \A to \B.
Using a Reverse Trigger
You can automate the planned switchover operation described above by configuring a REVERSE
TRIGGER and then issuing a STOP RDF, REVERSE command instead.
Reciprocal Configurations
In a reciprocal RDF configuration, two systems act both as a primary and as the backup to the
other.
With reciprocal configurations it is imperative that you use INCLUDE and EXCLUDE lists
specifying which database files each configuration will (and will not) protect. See “Reciprocal
and Chain Replication” (page 56) for more information.
The steps for performing a planned switchover from \A to \B in such a configuration are:
1. On system \B, stop RDF subsystem # 2. Note the local system time; you will need it later.
2. On system \A, stop the business applications that access the primary database (Applications
#1).
3. On system \A, stop TMF.
4. Wait for RDF subsystem #1 on \A to shut down.
5. On system \B, restart Applications #1.
At this point, the RDF subsystem is down on both systems, the business applications from
system \A are now running on system \B, the business applications that were running on
system \B are still running on system \B, and all audit information is being queued in TMF
audit trails on system \B.
6. When system \A is ready to resume its normal operations, restart TMF.
7. On system \B, restart RDF subsystem #2 (the RDF subsystem that replicates data from \B
to \A for the business applications that normally run on \B). The subsystem resumes its
processing exactly where it was when you stopped it in step 1.
8. On system \B, initialize RDF subsystem #1. In the INITIALIZE RDF command, include the
INITTIME option and specify the timestamp you noted in step 1. Configure the subsystem
to replicate data from \B to \A for Applications #1 (the business applications that were
moved from system \A to system \B).
134 Managing RDF