Migrating to Modern VCS from ClearCase in Eclipse Environments

Best Practices for Using ClearCase in Eclipse ProjectsThis article covers proven practices for integrating IBM Rational ClearCase with Eclipse-based development workflows. It’s aimed at developers, build engineers, and team leads who use Eclipse as their IDE and ClearCase as their version-control and configuration-management system. The goal is to minimize friction, avoid common pitfalls, and keep code, builds, and team collaboration stable and predictable.

Why combine ClearCase with Eclipse?

Eclipse is a widely used IDE with a rich plugin ecosystem; ClearCase provides strong configuration-management features (UCM and base ClearCase) and metadata controls that many enterprise teams rely on. Together they offer tight development workflows where file-level locking, baselines, and branching strategies can be enforced while letting developers code in a productive environment.

1. Choose the right ClearCase integration mode

• Use the ClearCase plugin for Eclipse (ClearCase Remote Client — CCRC — or ClearCase Explorer plugin) for everyday operations like checkouts, checkins, and version browsing.
• For teams that require full performance and advanced features, prefer the native ClearCase client integration over remote clients, especially for large repositories or heavy I/O operations.
• If your organization uses UCM (Unified Change Management), ensure your Eclipse plugin supports UCM operations (activities, streams, baselines) so developers can work within the established process.

2. Configure your Eclipse workspace and ClearCase views correctly

• Keep one Eclipse workspace per ClearCase view to avoid confusion. Mixing multiple views in a single workspace can lead to classpath inconsistencies and build issues.
• Prefer snapshot views for performance-sensitive local development and to enable offline work. Use dynamic views when you need immediate, server-side version visibility (but be mindful of network latency).
• Ensure your snapshot view mappings (load rules) are minimal and focused: load only the modules/packages you actively work on to reduce disk usage and improve indexing times.

3. Standardize checkout/checkin practices

• Enforce an explicit checkout-checkin policy: never edit files without checking them out first. Configure file system permissions and team guidelines to discourage editing without checkout.
• Use Eclipse’s team menu and ClearCase plugin commands for operations; avoid mixing command-line ClearCase operations with Eclipse actions unless your team understands the implications.
• Encourage frequent, small checkins linked to meaningful activities or UCM activities. This improves traceability and reduces merge complexity.

4. Manage builds and classpaths to avoid integration issues

• Keep build outputs (bin, target, etc.) outside of ClearCase-controlled directories or configure ClearCase to ignore build artifacts. Committing build outputs pollutes the repository and causes unnecessary overhead.
• Configure your Eclipse project classpaths to use workspace-relative paths or variable-based paths rather than absolute paths tied to specific view locations.
• For complex projects with generated sources, include a clear, documented build script (Ant, Maven, Gradle) that team members can run consistently. Store build scripts in ClearCase and keep them versioned.

5. Handle merges and branching carefully

• Adopt a clear branching strategy (stream-based UCM or named branches) and document it. Make sure developers know which branch/stream to use for features, fixes, and releases.
• Use Eclipse’s compare/merge tools or external merge tools integrated into Eclipse for conflict resolution. Ensure merge tools are configured to handle file encodings and line endings consistently.
• When performing merges, always run a local build and unit tests before checking changes back in. This catches integration problems early.

6. Automate common tasks where possible

• Integrate ClearCase operations into your CI/CD pipeline (UCM baselines, deliver, rebase) so builds and tests run automatically on committed changes.
• Use scripts to maintain and clean snapshot views, manage reserved/unreserved checkouts, and enforce naming conventions for activities and streams.
• Automate baseline creation and tagging for release candidates to provide reproducible builds.

7. Optimize performance and reduce IDE lag

• Limit the number of projects loaded in an Eclipse workspace. A cluttered workspace drains memory and slows down indexing.
• Turn off or fine-tune heavy Eclipse plugins that aren’t needed daily. Plugins that perform background scanning can cause conflicts with ClearCase view updates.
• Use ClearCase view cache settings and consider local SSDs for snapshot views to accelerate file access.

8. Keep metadata and configuration consistent

• Standardize file encodings, line endings, and autotype settings across the team. Divergent settings cause spurious diffs and merge conflicts.
• Store and version IDE project settings (where appropriate) in ClearCase, but avoid storing machine-specific settings (absolute paths, local JVM configs). Use shared project settings and team settings files where possible.
• Maintain and version ClearCase-related scripts, view configurations, and load rules in a central location accessible to the team.

9. Train the team and document workflows

• Provide onboarding documentation covering ClearCase view creation, loading modules, checkout/checkin, UCM activities, and how to resolve common conflicts within Eclipse.
• Run periodic refresher sessions and capture frequently asked questions in a team wiki. Include troubleshooting steps for common Eclipse + ClearCase issues (stale views, locked files, checkout failures).
• Encourage developers to add descriptive comments to checkins and link them to relevant tasks or change requests.

10. Troubleshooting common problems

• Stale or out-of-sync views: Refresh or recreate snapshot views; run cleartool update and verify load rules.
• Locked or reserved checkouts blocking work: Use cleartool lscheckout and unreserve or undo-checkout carefully, coordinating with the file owners.
• Build failures after merges: Run a clean build, check classpath and resource inclusions, and inspect local changes vs. incoming changes with compare tools.
• Slow Eclipse performance: Reduce workspace size, disable unnecessary builders, and verify view type (snapshot vs dynamic) suitability.

Example workflows

• Feature development (UCM):

  1. Create or select an appropriate stream.
  2. Create a new activity in Eclipse.
  3. Load a snapshot view for the stream with minimal load rules.
  4. Checkout, edit, and test changes locally.
  5. Checkin changes, associate them with the activity.
  6. Deliver to integration stream and run CI.

• Quick bugfix (base ClearCase):

  1. Create a new branch or use an existing maintenance branch.
  2. Load only required modules into a small snapshot view.
  3. Make the fix, run unit tests, and checkin.
  4. Merge to main/integration branch and verify build.

Final notes

Integrating ClearCase with Eclipse works best when teams adopt consistent conventions, limit workspace and view complexity, and automate repetitive tasks. Clear communication, documented workflows, and lightweight CI integration will reduce merge pain and keep development velocity steady.

Bold short fact: Use one Eclipse workspace per ClearCase view for predictable builds and fewer classpath issues.