Requirements and recommendations

In order to enable requests for mastership in one or more replicas and for those requests to be handled efficiently, specific conditions must be met.

In order for you to enable requests for mastership in one or more replicas, the following requirements must be met:
  • The VOB family must be at feature level 2 or higher. (All replicas in the VOB family must be at feature level 2 or higher, even if you are not going to enable requests in all of the replicas.) For more information about feature levels, see Feature levels.
  • The DevOps Code ClearCase client hosts and replica VOB server hosts all must have open, high-speed TCP/IP connections.

    A request for mastership makes remote procedure calls (RPCs) directly to remote servers and fails if the hosts are not connected. If a site has a firewall, developers at that site cannot request mastership from replicas at other sites, and developers at other sites cannot request mastership of any branches mastered by a replica at a site with a firewall.

  • Each replica must master its own replica object.

    If a replica does not master its own replica object, you cannot enable or disable mastership requests at the replica level. For information about reassigning mastership of the replica object, see Transferring mastership of a replica object.

For mastership requests to work efficiently, the following recommendations should be followed:
  • There should be no contention for branches or branch types among the sites. That is, only one person at a time requests mastership of a branch or branch type.

    If two or more developers at different sites compete for mastership of objects, mastership always will be in flux. In this situation, the project leaders and administrators must determine whether the branch sharing strategy needs to be changed. Using requests for mastership is not a substitute for using good branching and merging practices.

  • The replicas should exchange update packets frequently.

    Each replica needs current information about object mastership. If a replica is not up to date, requests for mastership from that replica cannot determine which replica masters the requested object. Also, if replicas exchange packets infrequently, a mastership request may cause the generation of a large update packet, which will take longer to generate and import.