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

Figure 10 shows synchronized databases where TMF has just been shut down. The databases are
synchronized because RDF applies all audit generated on \PRIMARY to the backup database
before the subsystem reads the TMF shutdown record and subsequently shuts down (the databases
are not, however, logically identical until RDF has actually shut down).
Figure 10 Synchronized Databases After STOP TMF Command
Primary Backup
Database
T1
T4
T3
T6
T2
T5
MAT
T4 T5 T6
Extractor
STOP TMF
Updater
Image File Database
T1
T4
T3
T6
T2
T5
T4 T5 T6
STOP TMF
Figure 11 shows unsynchronized databases. In this figure, T5 and T6 (transactions 5 and 6) have
not been transmitted to the backup system because of a physical disaster, such as fire or flood, or
because the primary or backup systems have failed. The databases are unsynchronized because
transactions were committed or aborted on the primary system before an unexpected shutdown,
and the extractor cannot transmit the commit or abort status records for those transactions (T5 and
T6) to the backup system.
NOTE: If you have not lost your primary system to a disaster, then, when the failed system comes
back online and RDF is restarted, RDF will put the backup database into synchronization with the
primary when it has caught up.
Understanding Database States 149