RDF/IMP, IMPX, and ZLT System Management Manual

Introducing RDF

HP NonStop RDF/IMP, IMPX, and ZLT System Management Manual—524388-002

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EMS Support

RDF/IMP, IMPX, and ZLT all support the Event Management System (EMS). They

direct their command, event, warning, and error messages to an EMS collector in the

form of fully-tokenized messages.

You can view messages in the EMS log online using Viewpoint or any other tool you

normally use for monitoring $0. Note that when you do so you are perusing the entire

EMS log. You can, however, use the standard EMS filter RDFFLTO to isolate RDF

messages into an entry-sequenced file which you then can examine using the

RDFSCAN online utility.

SMF Support

RDF supports the use of the NonStop Storage Management Foundation (SMF) product

on both the primary and backup RDF systems. The database on the primary system

can reside on SMF virtual disks, as can the replicated database on the backup system.

All combinations of replication from physical disk to virtual disk, virtual disk to physical

disk, and virtual disk to virtual disk are supported.

There are some issues and restrictions that you should be aware of before using RDF

in an SMF environment; these are discussed in detail under Using SMF With RDF in

Section 2.

RTD Warning Thresholds

RDF/IMP, IMPX, and ZLT allow you to designate a pair of RTD warning thresholds:

one for the extractor, and another for all of the updaters. Having set those thresholds,

you then can issue a STATUS RTDWARNING command with a designated repeat

interval to display information and statistics for only those processes (the extractor or

any updater) that have fallen behind the configured RTD threshold. For information

about setting the RTD threshold, see the SET RDF

command description.

Process-Lockstep Operation

Process-lockstep operation, which is available with the RDF/IMPX and ZLT products,

prevents an application from executing further processing based on a committed

business transaction until all audit associated with that transaction is safely stored in

the image trails on the backup system.

This is accomplished by means of a new procedure, named DoLockstep, that you call

immediately after calling endtransaction. With this lockstep protocol, the business

transaction is actually committed on the primary system prior to the start of the

DoLockstep operation, but the application is not allowed to continue processing until

DoLockstep has returned status to the application.

For information about this capability, see Section 14, Process-Lockstep Operation.