RDF/IMP and IMPX System Management Manual (RDF 1.4+)

Network Transactions
HP NonStop RDF/IMP and IMPX System Management Manual—524388-001
13-15
RDF Networks and Stop-Update-to-Time Operations
RDF Networks and Stop-Update-to-Time
Operations
Stop-update-to-time operations affect only the backup database of the particular
system on which they are initiated. If you have an RDF network, you can execute a
stop-update-to-time operation on any primary system in the network, but the operation
affects only the backup database of the system on which it is initiated (it does not affect
data in any other backup database, even for network transactions).
For example, suppose you have ten RDF subsystems in your RDF network, and most
transactions on each system touch two or more systems in the network. Thus, nearly
every transaction is a network transaction. If you execute a stop-update-to-time
operation on one of these systems, that operation only brings that particular
subsystem’s backup database into a consistent state with regard to transaction commit
times on the associated primary database. It does not execute undo operations on any
other backup systems in the RDF network.
To illustrate this, assume you began a transaction (T
10
) at 12:00 P.M., executed ten
updates on each of two primary systems in an RDF network (\A and \B), and
committed T
10
at 12:05. Assume further that you had previously issued a stop-update-
to-time operation on system \A, specifying 12:01 P.M. When the stop-update-to-time
operation completes, the data for T
10
is backed out of system \A’s backup database
because T
10
committed after 12:00 P.M. The data for T
10
on system \B’s backup
database, however, remains unaffected (because a stop-update-to-time operation only
applies to the backup system associated with the primary system on which it is
initiated).
Note also that it is rare for clocks on different systems to have exactly the same values,
thus rendering stop-update-to-time operations impossible to perform correctly across
multiple backup systems.
Sample Configurations
Two sample configurations follow, one for the network master and one for a non
network master. The network attributes are highlighted in bold.
Sample Network Master Configuration
The configuration that follows is for a network master RDF subsystem running from
\RDF04 to \RDF06:
SET RDF SOFTWARELOC $SYSTEM.RDF
SET RDF BACKUPSWAP $SWAP01
SET RDF LOGFILE $0
SET RDF PRIMARYSWAP $SWAP01
SET RDF UPDATERDELAY 10
SET RDF UPDATERTXTIME 60
SET RDF UPDATERRTDWARNING 60
SET RDF UPDATEROPEN PROTECTED