You can change the mastership of database objects such as records
and Workspace items to accommodate the changing needs of users in your environment.
You can transfer mastership of an object with a chmaster command
or with the GUI.
Mastership changes are appropriate in the following situations:
- You want to allow a user at another replica to modify a record or public
query that is mastered by your replica.
- You want to make changes to user information that is mastered by another
replica.
- You are decommissioning a replica, and you must transfer mastership of
all objects mastered by that replica to one of the remaining replicas.
Mastership changes are communicated among replicas by the standard synchronization
mechanism. The general procedure for changing mastership is as follows:
- At the master replica, change mastership of one or more objects to another
replica.
- At the old master replica, export an update packet from the old master
replica to the new master replica.
- At the new master replica, import the update packet.
Until the update packet that contains the mastership change is imported
at the new master replica, the mastership change is only in the packet, and
the replicas in the database family have different information about which
replica masters the object.
For example, the administrator at the
sanfran_hub replica transfers
mastership of the user group
QA_ENGINEERING to the
bangalore replica
and exports an update packet. At this point the following conditions exist:
- The sanfran_hub replica considers the user group to be mastered
by bangalore.
- The bangalore replica considers the user group to be mastered by sanfran_hub.
- No one at any replica can modify the user group.
When you complete the mastership transfer by importing the update packet
at bangalore, users at bangalore can modify the user group QA_ENGINEERING.
Considerations for mastership changes
If your family
includes any read-only or one-way replicas (replicas that import update packets
but do not export them), be careful about transferring mastership to these
replicas. After you give mastership of an object to a read-only or one-way
replica, you cannot change the object’s mastership unless you change the family’s
synchronization pattern.
You cannot undo a mastership change made at
your site by making the opposite change at your site.