Introducing Rdf - HP NonStop RDF J-series RVUs Management Manual

1 Introducing RDF

This manual describes the Remote Database Facility (RDF) subsystem as implemented in version
1, update 9 of the HP NonStop RDF/IMP, IMPX, and ZLT independent products. Customers
who install RDF 1.9 can use existing RDF configuration scripts provided the scripts are not
making use of new functionality.
This chapter, which is intended for all readers, discusses these topics:
• "RDF Subsystem Overview" (page 32)
• "User Interfaces" (page 38)
• "RDF Processes" (page 40)
• "RDF Operations" (page 42)
RDF monitors changes made to a production database on a local (primary) system and maintains
a copy of that database on one or more remote (backup) systems. Because it applies changes to
the backup database as soon as they are detected on the primary system, RDF keeps the backup
database continuously up to date with changes made by business applications on the primary
system. You are able, therefore, to switch your business operations from the primary system to
the backup system with minimal interruption and loss of data in the event of planned or
unplanned outages of the primary system. With NonStop RDF/ZLT, the failover involves no loss
of data.
RDF also allows you to use backup databases as read-only resources to balance the overall
workload and improve response times. Activities at a backup system can include querying the
database, processing heavy batch-reporting loads, and consolidating data from multiple sites
into one central site.
Backup systems might be located far from the primary system for protection against regional
disasters, communicating with the primary system over an Expand network.
System managers and operators control RDF through RDFCOM, a utility much like the TMFCOM
command interpreter used to access TMF.
RDF/IMP, IMPX, and ZLT generate fully-tokenized command, event, error, and warning messages
in the Event Management System (EMS) log. System managers and operators can monitor those
messages online using Viewpoint or whatever other tool they normally use for monitoring $0.
In addition, they can use the supplied EMS filter RDFFLTO with an EMS printing distributor to
isolate the RDF messages to an entry-sequenced file which they then can peruse using the
RDFSCAN utility.
RDF works with the Transaction Management Facility (TMF) subsystem.
There are three versions of the RDF product:
1. RDF/IMP (product number T0346) provides online product initialization, online database
synchronization, triple contingency support, subvolume-level and file-level replication,
stop-update-to-time (for quiescing the backup database to a stable state), and many other
features.
2. RDF/IMPX (product numbers T0346 and T0347) provides the same functionality as RDF/IMP,
but also replication of auxiliary audit trails, support for network transactions, and lockstep
operation.
3. RDF/ZLT (product number T0618) provides zero lost transaction (ZLT) protection using
mirrored disks.
NOTE:
HP NonStop RDF software works with HP NonStop S-Series servers, HP Integrity
NonStop NS-Series servers, and HP Integrity NonStop BladeSystems.
Before reading further in this manual, you should be familiar with the concepts, terminology,
and functions of the NonStop TMF product. You should know about the objects on which TMF
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