Welcome
Administering
Learn how to administer the product.
Administering DevOps Code ClearCase® MultiSite
Learn to configure and manage the DevOps Code ClearCase® MultiSite and Rational® ClearQuest® MultiSite environments to support development activities at different locations.
Implementation planning
Before you install and use DevOps Code ClearCase® MultiSite, you need to plan your implementation.
MultiSite use model
There are different aspects of your MultiSite use model that affect the implementation and deployment of a MultiSite environment.
Synchronization pattern
The synchronization pattern for a family defines which replicas exchange update packets and the direction of exchange.
Many-to-many synchronization
In the many-to-many synchronization pattern, each replica exchanges packets with all other replicas.

Overview
Learn general information about the product.
Installing
Learn how to install the product.
Upgrading and migrating
Learn how to upgrade and migrate data for the product.
Administering
Learn how to administer the product.
- Administering DevOps Code ClearCase®
  Learn about performing administrative tasks for a DevOps Code ClearCase® community including managing software licenses, user and group accounts, ClearCase server and client hosts, shared data, and the network that connects them.
- Administering platforms for DevOps Code ClearCase®
  Learn how to perform DevOps Code ClearCase® administrative tasks on supported platforms.
- Administering DevOps Code ClearCase® MultiSite
  Learn to configure and manage the DevOps Code ClearCase® MultiSite and Rational® ClearQuest® MultiSite environments to support development activities at different locations.
  - Introduction
    DevOps Code ClearCase® MultiSite and add a powerful capability to DevOps Code ClearCase and . With MultiSite, developers at different locations can use the same DevOps Code ClearCase versioned object base (VOB) or . For DevOps Code ClearCase, each location (site) has its own copy (replica) of the VOB. At any time, changes made in one replica can be sent in update packets to other replicas. You can manage replicas by using the command-line tools.
  - MultiSite operation
  - Implementation planning
    Before you install and use DevOps Code ClearCase® MultiSite, you need to plan your implementation.
    - MultiSite installation
      MultiSite is installed as an optional product component during the DevOps Code ClearCase® installation.
    - MultiSite licensing
      A MultiSite license is required to access an object in a replica by a MultiSite command or GUI, by a DevOps Code ClearCase® command or GUI, or by a standard operating system command.
    - Shipping server use with DevOps Code ClearCase® and Rational® ClearQuest®
      If you use both DevOps ClearCase® MultiSite and DevOps ClearQuest® MultiSite, you use the same shipping server for both products. The shipping server is installed when you install DevOps ClearCase MultiSite.
    - DevOps Code ClearCase® use model
      Before development work is started in any VOB, the project manager and administrator must define the DevOps Code ClearCase® use model. For example, the project manager must specify the branches, labels, and triggers that are used for development and integration work.
    - MultiSite use model
      There are different aspects of your MultiSite use model that affect the implementation and deployment of a MultiSite environment.
      - Deploying VOB families
        When creating VOB replica families, you must decide how to administer the sites and configure mastership for the replicas.
      - MultiSite, time, and time zones
        In MultiSite, time stamps are stored in Universal Coordinated Time (UTC) and are printed to reflect the local time.
      - Time rules in config specs
        Time rules in config specs are not absolute. The version selected by a time rule can change after an update packet is imported at your replica.
      - Mastership strategy
      - Identities and permissions strategy for VOB replicas
        A replica can preserve identities and permissions, preserve permissions only, or preserve neither identities nor permissions (nonpreserving).
      - Managing rolemaps, policies, and object-rolemap bindings
        There are several administrative consequences arising from the differences between policy mastership and rolemap mastership, and also from the replication mode of the VOB family.
      - Group selection in replicas according to feature level
        The group selection algorithm for VOBs at feature level 8 is different from the feature level 7 algorithm.
      - Synchronization
        The main factors to consider when planning replica synchronization are method, scheduling, and pattern.
      - Synchronization pattern
        The synchronization pattern for a family defines which replicas exchange update packets and the direction of exchange.
        Directions of exchange
        Synchronization can be unidirectional or bidirectional. In most cases, you will use bidirectional synchronization.
        One-to-one and ring synchronization
        The one-to-one and ring (or round-robin) patterns are simple patterns that are most suitable for small numbers of replicas. As the number of replicas increases, so does the amount of time for changes originating at one replica to be received at a replica at the other side of the ring.
        One-to-many synchronization
        The one-to-many pattern involves one replica, or root site sending packets to all other replicas in the family.
        Many-to-many synchronization
        In the many-to-many synchronization pattern, each replica exchanges packets with all other replicas.
      - Synchronization schedule
        The synchronization schedule for a family defines when replicas in the family send and receive updates. The schedule is affected by many factors, including the rate of development at different sites, the connections among sites, and whether you use MultiSite as a backup strategy.
      - Use of MultiSite for VOB backups
        You can use MultiSite as part of your VOB backup strategy.
      - Scrubbing parameters for replicas
        When a command makes a change to a replica, an entry is recorded in the replica’s operation log. Also, when you export an update packet, an export_sync record is created for each target replica. These records are used by the recoverpacket command to reset a replica’s epoch number matrix.
      - Path names that contain spaces
        On computers running Windows™, if the path name of a receipt handler or a shipping order contains spaces, DOS short name resolution must be enabled for the file system on which the receipt handler or shipping order is located. This property is enabled by default. If this property is not enabled, the shipping server cannot invoke the receipt handler or process the shipping order.
    - Responsibilities of MultiSite administrators
      The MultiSite administrator must perform the tasks described in this topic.
  - MultiSite command set
    This section summarizes the commands for DevOps ClearCase® MultiSite and DevOps ClearCase that display DevOps Code ClearCase MultiSite information.
  - Packet transportation methods and configuration
    The method you choose for transporting packets between replicas depends on connectivity. If your replicas do not have IP connectivity, you must use a file-based transport method. If your replicas have connectivity, you can use the store-and-forward facility.
  - Feature levels
    Feature levels allow different replica hosts in a VOB family to run different versions of DevOps Code ClearCase®. You can raise the feature level of either a single replica host or an entire VOB family.
  - Creating VOB replicas
    Before creating a replica, you must make decisions about branching, mastership, identities and permissions preservation, and method of packet delivery.
  - Replica synchronization
    Replica synchronization uses the same export-transport-import procedure that is used during replica creation.
  - Administering replicas
  - Using MultiSite for VOB backup and interoperability
    You can use DevOps Code ClearCase® MultiSite to back up a VOB and to provide access to VOBs in a heterogeneous network.
  - Troubleshooting MultiSite operations
    When you encounter a situation where running a DevOps Code ClearCase® MultiSite command produces an unexpected result, or produces a warning or error message, the information in this section can assist you in troubleshooting the problem.
Developing
Learn how to develop software with DevOps Code ClearCase® and ClearCase Remote Client.
Managing change and releases
Learn how to manage change and release in the product.
Integrating
Learn how to integrate DevOps Code ClearCase® with other products.
Tutorials
Complete tutorials with specific learning objectives for the product.
Extending product function
Learn how to extend the product.
Reference
Review reference information for the product.
Glossary

Many-to-many synchronization

In the many-to-many synchronization pattern, each replica exchanges packets with all other replicas.

Figure 1. Many-to-many synchronization pattern

Advantages:

For companies with few sites, this pattern keeps each replica’s epoch table the most accurate for all siblings.
If one site is unavailable, the other sites do not have to change their patterns to continue synchronizing.

Disadvantages:

Each administrator must maintain more synchronization jobs and spend more time keeping, creating, tracking, and importing packets.
Fully synchronizing the family requires n*(n-1) packets and connections, where n represents the number of replicas in the family. For example, if there are four siblings displayed in Figure 1, a total of 12 connections are required for synchronization. Similarly, a family of five siblings would require 20 packets and connections, while a family of six siblings would require 30 packets and connections, and so on. Transferring all these packets around can be inefficient and expensive.