Databases Reference
In-Depth Information
Synchronization and Remote Partitions
Synchronization in the presence of remote partitions is similar in many ways to a restore
process in the presence of remote partitions. Figure 40.3 shows one server (Source Master)
with remote partitions on two other servers (Source Slave1 and Source Slave2). If the
synchronization operation works with only the database on Source Master and the data-
base on the server Target Master, and doesn't take into account the remote partitions, we
run into a problem.
Synchronize
Command
Source Master
Target Master
Source
Slave 1
Target
Slave 1
Source
Slave 2
Target
Slave 2
FIGURE 40.3
Synchronizing databases with remote partitions requires special attention.
The resulting database on the target server (Target Master) looks for its remote partitions
on the original source servers (Source Slave1 and Source Slave2), represented in the figure
by broken lines. Two different master servers cannot reference a single set of remote parti-
tions. With the situation represented by the broken lines, any attempt by the target server
to reach the remote partitions will fail.
To avoid this problem, the synchronization operation must synchronize the source slave
servers to the target slave servers and adjust the corresponding data sources. To accom-
plish this, make sure that the
Synchronize
command includes additional information for
each source slave server with which a target slave server should synchronize. The func-
tionality in the Synchronize Database Wizard enables you to add this information. In fact,
it won't let you proceed if you don't add the information.
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