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

Managing RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
5-21
Preparing for Application Processing on the Backup
System
Preparing for Application Processing on the Backup System
Before application processing starts on the backup system following a successful
takeover operation, you might need to update statistics for SQL/MP database tables and
recompile SQL/MP program files.
After a takeover operation occurs, the following considerations apply to SQL/MP tables
protected by RDF:
•
If the applications are already in place on the backup system, all you need to do
before bringing the applications online is make sure the SQL tables are enabled for
auditing.
•
Three other operations might help maintain acceptable performance for the
applications:
•
Evaluate whether to perform an update statistics operation on database tables.
•
Evaluate whether to recompile the application programs with the SQL compiler.
•
Use the CHECK INOPERABLE PLANS SQL/MP compiler option for any
necessary recompilations.
Before operations that would cause automatic SQL compilation, you can recompile
SQL/MP program files to check for compilation errors before running the programs. For
a complete description of operations that invalidate application programs, causing
automatic SQL compilation, see the Compaq NonStop™ SQL/MP Installation and
Management Guide.
Restoring the Primary System
When the failed primary system is restored to operable condition, you can take the
following steps to restore the original RDF configuration and make the old primary
database the current primary database again (where \A is the old primary system and \B
is the old backup system):
1. Stop the applications and TMF on \B.
2. Save the database on \B to tape.
3. Restart the applications and TMF on \B.
4. Initialize RDF on \B to the shutdown timestamp generated in Step 1.
5. Configure RDF to go from \B to \A.
6. Start RDF (\B to \A) with update off.
7. Restore the database on \A.
Note. If you are using the triple contingency feature, you must issue a COPYAUDIT command
after the takeover operations are complete to copy missing audit from the backup system that
has the most to the one that has the least. See Section 10, Triple Contingency
for details about
this situation.