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

Managing RDF

Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001

5-16

Reciprocal Configurations

In a reciprocal RDF configuration, two systems act both as a primary and as the backup

to the other.

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’ll 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).

System \A System \B

Backup

Primary

Backup

Primary

RDF Subsystem #1 RDF Subsystem #1

RDF Subsystem #2RDF Subsystem #2

Applications #1

Applications #2