RDF System Management Manual for J-series and H-series RVUs (RDF Update 13)

For information about this capability, see Chapter 15 (page 299).
Support for Network Transactions
The RDF/IMPX and ZLT products support network transactions: transactions that update data
residing on more than one RDF primary system.
More specifically, the updates for a transaction on one of the two primary systems might have
been successfully transmitted and applied to the associated backup database, but a disaster brought
down the other primary system before the updates by the transaction on that system could be sent
to its backup database. After executing RDF takeover operations on both backup systems, the data
from the network transaction would be present in one backup database but not in the one brought
down by the disaster. Thus the distributed backup database is inconsistent with regard to the
affected network transaction.
For information about this capability, see Chapter 14 (page 286).
RDF and NonStop SQL/MX
RDF can replicate NonStop SQL/MX user tables and indexes as well as NonStop SQL/MP objects
and Enscribe files.
For information about this capability, see Chapter 16 (page 316).
Zero Lost Transactions (ZLT)
Zero Lost Transactions (ZLT), which is available only with the RDF/ZLT product, is a functional
capability that uses mirrored disks to guarantee that no committed transactions on the primary
system will be lost in the event of an RDF takeover by the backup system.
For information about this capability, see Chapter 17 (page 329).
Monitoring RDF Entities With ASAP
ASAP (Availability Statistics and Performance) allows many different subsystem entities to be
monitored across a network of NonStop servers. The status and statistics for the entities are collected
on a single system, and are then monitored either through the ASAP command interface or through
the ASAP graphical user interface PC client.
RDF/IMP, IMPX, and ZLT are instrumented to feed state information to ASAP, thus allowing RDF
subsystems to be monitored, in an integrated way, alongside all other subsystems supported by
ASAP. The following RDF entities report state and statistical information to ASAP:
• Monitor
• Extractor
• RDFNET (optional)
• Receiver
• Purger
• Updater
For information about using ASAP to monitor RDF entities, see Appendix E (page 492).
Other RDF Features 47