Removing unneeded ClearCase replicas

Deleting a Replica

This section describes how to remove a replica. You must complete all steps; if you do not, synchronization and mastership problems can occur in other replicas in the family. When you remove a replica, the replicas in its family stop tracking epoch numbers for that replica. Removing a replica does not delete the VOB database. Removing a replica requires two synchronization cycles: one to transfer mastership of all of the replica’s objects to another replica, and one to inform all other replicas that the removed replica is no longer participating in the update process. Because this information can be communicated only through the synchronization process, you cannot remove a replica at its own site, because doing so prevents the replica from creating update packets.

After a replica is removed from a family, it no longer participates in synchronization activities and MultiSite information is not tracked. The replica no longer updates its oplog, and you cannot transfer mastership of any object in that replica.

Note: If a VOB replica is deleted mistakenly and you want to restore it frombackup, see Restoring and Replacing VOB Replicas on page 198. If a VOB replica’s storage directory is lost and there is no backup, see Cleaning Up After Accidental Deletion of a Replica on page 204.

In this scenario, the replica tokyo in the VOB family \tests is being removed.

1 At the site of the replica to be removed, complete all development work in the replica and use lscheckout or the Find Checkouts tool (Windows) to verify that all checkouts are resolved in the replica to be removed:

SHINJUKU> cleartool lscheckout –all \tests
(no output means no checkouts)

2 Transfer mastership of all objects to another replica.

At the site of the decommissioned replica, transfer mastership of all objects it masters to another replica. If the decommissioned replica is not self-mastering, transfer mastership to its master replica. If the replica is self-mastering, you can
choose any replica. In this example, the administrator determines which replica masters tokyo, and
then transfers mastership to the master replica (in this example, sanfran_hub):

SHINJUKU> cleartool describe –fmt "%[master]p\n" replica:tokyo@\tests
sanfran_hub@\tests

SHINJUKU> multitool chmaster –all –long sanfran_hub@\tests
Changed mastership of versioned object base \tests
...
Changed mastership of all objects

The replica that receives mastership can later transfer mastership to other replicas.

If mastership is not transferred for all objects, you must fix the problem and reenter the chmaster –all –long command. For an example, see Transferring Mastership of All Objects Mastered by a Replica on page 138. If there are problems you
cannot fix, another replica can recover from the error by assuming mastership of the objects.

3 Export and send an update packet from the decommissioned replica.

The decommissioned replica must send its final changes, including checkins and mastership changes, to the replica receiving mastership. The decommissioned replica can broadcast its final changes to all other replicas, but it must update its
master replica (sanfran_hub in this example).

SHINJUKU> multitool syncreplica –export –fship sanfran_hub@\tests
Generating synchronization packet c:\Program
Files\Rational\ClearCase\var
\shipping\ms_ship\outgoing\sync_tokyo_23-Dec-02.09.33.02_3447_1
- shipping order file is c:\Program
Files\Rational\ClearCase\var\shipping\ms_ship\outgoing\sh_o_sync_to
kyo_23-Dec-02.09.33.02_3447_1
Attempting to forward/deliver generated packets...
-- Forwarded/delivered packet c:\Program
Files\Rational\ClearCase\var
\shipping\ms_ship\sync_tokyo_23-Dec-02.09.33.02_3447_1

4 Import the update packet at the replica that is (or will become) the master of the
decommissioned replica.

GOLDENGATE% multitool syncreplica –import –receive
Applied sync. packet
/opt/rational/clearcase/shipping/ms_ship/incoming/sync_tokyo_23-Dec
-02.09.33.02_3447_1
to VOB /net/goldengate/vobstg/tests.vbs

5 At the master replica, remove the decommissioned replica.

GOLDENGATE% multitool rmreplica tokyo@/vobs/tests
Deleted replica "tokyo".

6 At the master replica, export and send an update packet to the remaining replicas
in the VOB family.

This update packet notifies the other replicas of the replica removal.

GOLDENGATE% multitool syncreplica –export –fship replica-names
Generating synchronization packet ...

7 At the removed replica, remove the VOB storage directory of the removed replica.

SHINJUKU> cleartool rmvob \\shinjuku\vobs\tests.vbs

Remove versioned object base "\\shinjuku\vobs\tests.vbs"? [no] yes
Removed versioned object base "\\shinjuku\vobs\tests.vbs".