Avocent DSView 3, Installer/User Manual

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Chapter 3: DSView 3 Software Servers 83
administrator then changes something about the item on the hub server. When the replication task
runs, two things may happen.
In a few instances where no conflict occurs, both changes will be incorporated and replicated. For
example, if the hub server’s administrator adds username JaneDoe to the existing user-defined user
group Accounting and the spoke server’s administrator adds username JohnDoe to the Accounting
user group, both names will be added and replicated.
In most other instances where the changes are mutually exclusive or some other conflict occurs, the
most recent change will be the only change accepted and replicated. For example, if the hub
server’s administrator associates a unit with the Miami site, and the spoke server’s administrator
associates the same unit with the Chicago site, the change that was made closest to the time of
replication (that is, the most recent change) will be accepted and replicated.
This emphasizes the importance of ensuring the hub and spoke servers’ clocks are synchronized.
The exception to the last-change rule is when one of the actions deletes an item - in that case, the
deletion is accepted and replicated, regardless of timing. For example, if a unit was deleted on the
hub server, and then the contact information for the same unit was changed on the spoke server a
minute later, the unit will be deleted when the replication task is run.
On a spoke server, you may enable a replication task property that forces the spoke server to
retrieve a snapshot of the hub database rather than synchronizing changes back and forth. The
snapshot is a copy of the hub at the time of the operation. This feature is not normally used; it is
intended to help recover a system when replication has failed.
To display replication results and/or change the replication schedule for a spoke
server:
1. On the spoke server, click the System tab.
2. Click Tasks in the top navigation bar. The Tasks window will open.
3. Select the Database Replication task. The Task Results - Database Replication window will
open. This window contains the results of the most recent replication.
4. To display or change the replication schedule, click Schedule in the side navigation bar. The
Task Schedule - Database Replication window will open.
By default, the replication task runs every 12 hours. You may change the schedule type, start
time, date and interval.
5. To force the spoke server to retrieve a snapshot of the hub database rather than synchronizing
changes, click
Properties in the side navigation bar and then click the Perform a hub database
snapshot the next time this task executes checkbox. This setting will be reset to unchecked after
the operation completes.
6. If you made any changes, click Save and then Close .
You may also display the replication schedule from the hub server, but you cannot change it.
To initiate an immediate replication on a spoke server:
1. On the spoke server, click the System tab.