Replicated administrative VOB hierarchies

When you use administrative VOB hierarchies (including those created by UCM) in an HCL VersionVault MultiSite environment, special considerations apply to replication.

Whenever a VOB that is part of an administrative VOB hierarchy is replicated, other members of the hierarchy (or at least those members farther up in the hierarchy) must also be replicated. In the example shown in the following figure, the VOB \dev has an AdminVOB hyperlink to the administrative VOB \admin_dev and \dev is replicated. Therefore, all sites that have a replica of \dev must also have a replica of \admin_dev.
Figure 1. Replication requirements of administrative VOB hierarchies

Figure 5 shows the administrative VOB hierarchy that was shown in Figure 4. This VOB hierarchy is located in Boston. A VOB in the hierarchy, \dev, has a replica in San Francisco.

An attempt by a client VOB replica to create an AdminVOB hyperlink to an administrative VOB results in an error in these cases:
  • The administrative VOB is not replicated.
  • Both the client VOB and administrative VOBs are replicated, but the client VOB does not master the VOB object of its family.
When a client VOB replica attempts to create a hyperlink to a replicated administrative VOB, the operation succeeds with a message that the administrative VOB must be replicated to the same sites at which the client is replicated (although it can be determined that the administrative VOB is replicated, it cannot be determined that it is replicated at the client VOB replica sites).

The figure also shows that the VOB \admin_re has an AdminVOB hyperlink to the VOB \admin, but \admin_re is not replicated. In this situation (an administrative VOB is replicated but one or more lower-level members of its hierarchy are not), cleartool type-creation commands produce messages of this form:

Error: Unable to find replica in registry for VOB with object ID:"<VOB-oid>"
Error: Unable to locate versioned object base with object id:"<VOB-oid>"

These errors are not important if you did not intend to replicate the VOB referred to in the message, and they do not prevent creation of the type as specified.

When you replicate a VOB that is part of an administrative VOB hierarchy, the mkreplica –export command prints a reminder that you must replicate all VOBs in the hierarchy above the VOB you are replicating. The output lists such VOBs. The command does not check whether the administrative VOBs are replicated, so you can ignore the message if you have already replicated them.

Because local type objects in a VOB are linked to global type objects in its administrative VOB hierarchy, all members of the hierarchy should be synchronized at the same time. Otherwise, users may have trouble accessing type objects.