Configuration items and integration types
A VOB is a permanent, read-only data repository. It stores anything that can be represented as a file or a directory and also ClearCase specific data such as labels, branches, etc.
Files and directories in ClearCase VOBs are called elements. An element consists of a set of versions, organized into a version tree. Each version represents one revision of a file under source control.
A ClearCase view is a workspace that provides users access to versions of elements in VOBs. It enables users to work in parallel. A view's configuration specification (config spec) is a filter mechanism (a set of ordered rules) used to select at most one version of each element. It determines which version of each element is visible in the view. All started views are by default visible under the
'M:\' drive. A view can be mapped to any other available drive.
The default config spec, which is for simple serial development, looks as follows:
element * CHECKEDOUT element * /main/LATEST
Branches enable parallel development. They allow different projects and/or users to use the same sources at the same time. In a parallel development environment, you will most likely work on element branches other than
/main. The view config spec needs to be changed to select the correct branches and versions.
A sample config spec for working on a different branch than
element * CHECKEDOUT element * /main/mybranch/LATEST
A Rhapsody Unit is a file system representation of modeling elements such as projects, packages, use case diagrams, object model diagrams, components, etc.
Each unit has a specific extension depending on its type:
Table 1. Unit types and corresponding file extension
|Packages / profiles||.sbs|
|Object model diagrams||.omd|
|Use case diagrams||.ucd|
|Classes, actors & use cases||.cls|
|Controlled files||any extension|
By default components, controlled files, profiles, and packages are units whereas diagrams, classes, actors and use cases are no units. It is possible to convert diagrams, classes, etc. into units so that these elements are represented on the file system in separate files. Those newly created units can then be added to source control.
In Rhapsody you can create units as follows:
Go to the Rhapsody browser, right-click on the model element and select 'Create Unit'.
Figure 1. Rhapsody Units
Each Rhapsody unit corresponds to a ClearCase element. If parallel work on the model elements in such a package (unit file / ClearCase element) is required, following steps can be taken:
- Increase the unit granularity by either reorganizing the model elements of a package into smaller sub-packages or by creating unit files for some of the model elements (e.g. classes). This approach will increase the number of ClearCase elements, while decreasing their individual size. Checking in or out a whole package with all nested model elements (descendants) can take more time for big models.
- Keep the Rhapsody model organization as is and create a branch for the corresponding element in ClearCase. This leads to parallel access to multiple versions of the same model element(s). This approach will increase the number of versions and branches of the model element. It requires a Diff/Merge session after the changes to the parallel branches have been completed. The resulting additional version contains the changes of all involved branches
In practice you may use a combination of those two approaches depending on your business needs.
Rational Rhapsody supports CM tools, including Rational ClearCase, in either of two main modes - Batch and SCC.
Remark: Batch Mode is available on Windows and Linux whereas SCC mode is available on Windows only.
Batch mode is the traditional method of interacting with CM tools that do not conform to the SCC standard. In this mode, Rational Rhapsody has a custom set of properties for each tool that launches tool-specific commands for the CM operations.
SCC mode is an alternative method of interacting with CM tools that conform to the SCC standard. In SCC mode, one set of properties can be enough to interface with dozens of SCC-compliant CM tools, without further customization. You interact directly with the GUI elements for the CM tool to perform SCC-supported operations. Return status information, or error information in the case of failure, comes directly from the CM tool. In this way, you have more direct CM tool interaction and receive more meaningful feedback on CM operations.
Each of those integration modes has advantages and disadvantages. To help you decide which mode might be best for your situation, this integration guide provides you with information about these differences. It also shows you how to configure the different modes along with a wide range of properties for each mode. In order to decide whether you should use batch mode or SCC mode, see .
Remark: If you want to use Rational ClearCase UCM (Unified Change Management) then SCC mode is the preferred option. However, you can still use UCM in batch mode on Linux and Windows if you set the so called UCM activities directly within ClearCase.