IBM Rational ClearCase - Features

Features

• Build auditing: The networked filesystem provided by MVFS allows for build auditing. Builds in views which use the MVFS are able to monitor and record file I/O operations performed during the build process, and associate each such event with the command which triggered it. This allows ClearCase to produce a bill-of-materials which it calls a Configuration Record (CR) for all builds and enable traceability for either software configuration management purposes or as part of a larger Application Lifecycle Management process. Build auditing is performed with command-line tools such as a built-in make tool (omake, clearmake) or by using the clearaudit command which can invoke a separate build tool.
• VOB (Versioned Object Base): A repository that stores versions of file elements, directory elements, derived objects, and metadata associated with these objects. With MultiSite, a VOB can have multiple replicas, at different sites.
• Configuration Record: The bill-of-materials artifact produced as the result of build auditing that contains:
  • Build procedure: The method (script, makefile, ...) that invoked the build
  • Inputs: All files (and their specific versions) that were used for a particular build.
  • Outputs: All derived object (DO) files (and any dependent DOs) produced as a result of the build.

The dependency information is stored in a hidden configuration record which can be shown for each derived object. The configuration record can be used to set up another view showing all files that have been read before during the build time. Alternatively, you can use the configuration record to apply a label to the files (and versions) that were read during the build.

• Build Avoidance: Use of MVFS (MultiVersion File System) allows derived objects built in one dynamic view to be automatically "copied over" to another dynamic view requiring "exactly the same" derived object. Two derived objects are deemed to be "exactly same" if they have the same configuration record (ClearCase terminology, also called bill of materials). Shared derived objects will be physically present on the VOB server, and not in the views that reference them. The process of "copying over" is called winking in in ClearCase terminology. This feature requires that the clearmake or omake tools are used instead of other build systems.
• Unix/Windows Interoperability: VOBs hosted on *nix (Solaris, Linux, AIX, HP-UX, IRIX primarily) servers can be accessed with dynamic views, snapshot views, or the new web protocol based client: the CCRC on Windows clients. VOBs hosted on Windows servers can be accessed with snapshot views or CCRC from Unix clients, but not dynamic views due to the Windows server returning file paths with backslashes as the path delimiter. There is a 3rd party patch for Linux to enable dynamic views from Windows VOBs.
• Integration With Other Products: Other products (originally) from Rational Software, notably ClearQuest and Rational Rose, integrate with ClearCase. ClearCase also integrates with TextPad, Microsoft Visual Studio, Code::Blocks, NetBeans and the Eclipse IDE through a plugin. There are also Emacs and Vim plugins available.
• Space Saving: ClearCase dynamic views can save huge amounts of space and allow for some measure of a shared work environment.