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

audit to the backup database. One can typically observe updater RTD times in the range of 1-20
seconds, although it may only take an updater a fraction of one second to apply 20 seconds worth
audit.
With FASTUPDATEMODE ON, as a receiver receives an extractor message, it buffers all the audit
sent in that message by the extractor, writes those buffers immediately to the image trails, and then
makes that data immediately available to the updaters. Depending on the value of the
UPDATERDELAY attribute in the global RDF configuration record, the updaters can then read the
image trails and apply the freshly written audit to the backup database immediately, thereby
keeping updater RTD times to the lowest possible value. Because the receiver writes the audit
immediately to the image trails after processing each extractor message, having FASTUPDATEMODE
set ON can impact extractor-to-receiver throughput.
For a complete discussion of FASTUPDATEMODE, see the description involving the SET RECEIVER
command in Chapter 8 (page 175).
To configure an RDF receiver process named $RECV to run as a process pair in CPUs 0 and 2 of
the backup system at a priority of 185 with FASTUPDATEMODE off, and to have the RDF image
trail file (with a primary extent size of 3000 pages and a secondary extent size of 3000 pages)
reside on the volume $IMAGE, issue the following commands:
]SET RECEIVER ATINDEX 0
]SET RECEIVER PROCESS $RECV
]SET RECEIVER CPUS 0:2
]SET RECEIVER PRIORITY 185
]SET RECEIVER RDFVOLUME $IMAGE
]SET RECEIVER EXTENTS (3000,3000)
]ADD RECEIVER
You cannot start RDF until you have configured a master receiver process.
You can issue ADD RECEIVER commands only when RDF is stopped.
Purger Process
Use SET PURGER and ADD PURGER commands to configure the following purger attributes:
• CPUS primary-CPU : backup-CPU
• PRIORITY
• PROCESS
• RETAINCOUNT
• PURGETIME
The CPUS attribute specifies the processors in the backup system in which the purger is to run.
The PRIORITY attribute specifies the priority at which the purger will run. You should set the purger’s
priority higher than that of any application’s process and higher than that of any RDF updater
process.
The PROCESS attribute supplies a name for the purger process. You should specify a meaningful
mnemonic such as $PURG. The process name can be any unique valid process name up to six
characters, including the $ symbol. However, you cannot specify HP reserved process names that
are of the form $X*, $Y*, or $Z*, in which * is any alphanumeric string.
The RETAINCOUNT attribute specifies how many of the most recent image trail files will be retained
on disk for each image trail. The default value is 2. For details about the RETAINCOUNT attribute
and triple contingency, see Chapter 10 (page 264).
The PURGETIME attribute specifies the number of minutes the purger process waits between attempts
to purge redundant image trail files. The default value is 60.
To configure an RDF purger process named $PURG to run as a process pair in CPUs 0 and 2 of
the backup system at a priority of 185, and to ensure that at least six image trail files are always
retained on disk, issue the following commands:
Initializing and Configuring RDF 83