Chapter 2 Data Replication
12
2
2
2.
.
.3
3
3
R
R
Re
e
ep
p
pl
l
li
i
ic
c
ca
a
at
t
ti
i
io
o
on
n
n
O
O
Op
p
pe
e
er
r
ra
a
at
t
ti
i
io
o
on
n
ns
s
s
a
a
an
n
nd
d
d
S
S
St
t
ta
a
at
t
te
e
e
T
T
Tr
r
ra
a
an
n
ns
s
si
i
it
t
ti
i
io
o
on
n
ns
s
s
This section describes the replication operations and state transitions.
Figure 2-2 Replication Operations and State Transitions
The pair setting is specified
but MV and RV are separated.
sep/exec
Difference between MV and
RV is being reflected.
The pair setting is specified
and synchronization has been
established.
exec : Executing Replicate, Separate, or Restore
sync : Replicate or Restore synchronization state
rpl : replicate (Replicate)
rpl/exec ............. Executing synchronization
rpl/sync ............. Synchronization state
sep : separate (Separate)
sep/exec ............ Executing Separate
separated .......... Separate completion state
rst : restore (Restore)
rst/exec ............. Executing Restore
rst/sync ............. Synchronization state
•
When Restore(update) is
executed, updates to MV are
reflected to RV.
• When Restore(protect) is
executed, updates to MV are not
reflected to RV.
• As a rule, access to RV is not
allowed.
MV RV
rpl/exec
MV RV
separated sync
rst/exec
• MV and RV can be
updated.
Replicate
• RV cannot be updated.
Restore
• RV cannot be updated.
Separate
• As a rule, RV cannot
be updated.
•
When Restore(protect) is executed,
Synchronous State (rst/sync) is
placed and then automatically
changed to Separated State
(separated).
MV RV
rpl/sync
rst/sync
•
Updates to MV are reflected to RV.
• As a rule, access to RV is not
allowed.
MV RV