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

You can peruse messages in the EMS log on your terminal screen by using Viewpoint or whatever
other tool you normally use for monitoring $0. When you do that, you are dealing with the entire
EMS log (not just RDF messages).
To isolate RDF messages from the rest of the EMS log, you can use the supplied EMS filter
RDFFLTO with an EMS printing distributor to produce an intermediate entry-sequenced file
that you then can scan using the RDFSCAN utility.
Using RDFSCAN commands, you can specify:
• A starting point for scanning the intermediate RDF message file
• How many records to scan
• Text to search for in the file
Tasks and examples for using RDFSCAN commands appear throughout the manual. Reference
information for all commands appears in Chapter 9 (page 245).
Tasks
To maintain a duplicate of the primary database on the backup system, RDF performs four
fundamental tasks:
• On the primary system, the extractor process captures audit information from the TMF MAT
and, optionally, from auxiliary audit trails.
• On the primary system, the extractor process filters out audit information that is not relevant
to the backup database (audit information for volumes or files not protected by RDF) and
then transmits the relevant audit information to the backup system. These records on the
backup system are called image records.
• On the backup system, the receiver process accepts the filtered audit information, sorts it,
and then writes it to the appropriate RDF image trail.
• On the backup system, updater processes read the records from their image trail files and
pass them to the disk process. The disk process interprets them and performs the logical
REDO operation for each record, updating rows or records in the backup database.
Figure 1-3 illustrates these tasks as they are performed during normal processing when RDF
updating is enabled. The sequence of events differs when updating is disabled, as explained in
“RDF Operations”.
44 Introducing RDF