Implement DRb client connection in experiments Runner

## Metadata - **Commit Message**: `feat(experiments): implement DRb client connection` - **Branch**: `feature/m3-drb-client` ## Background and Context The Runner's `attach_to_running_server` checks if `$manager` is non-nil and `spawn_ephemeral_server` polls `$manager` in the parent process. Neither approach works because the DRb client connection is never actually established. A proper DRb client connection with retry logic and failure handling is needed. ## Expected Behavior Attach mode connects via `DRbObject.new_with_uri('drbunix:tmp/aethyr.drb')`. Spawn mode forks, waits for the DRb socket file, then connects. Both modes have timeout handling with clear error messages on failure. ## Acceptance Criteria - [ ] `attach_to_running_server` uses DRb connection via `DRbObject.new_with_uri` - [ ] `spawn_ephemeral_server` forks and waits for DRb socket before connecting - [ ] Connection retry with configurable timeout implemented - [ ] Clear error messages on DRb connection failure - [ ] All existing tests continue to pass ## Subtasks - [ ] Code: Add DRb client logic to experiments Runner with `DRbObject.new_with_uri` connection - [ ] Code: Implement connection retry with timeout in attach mode - [ ] Code: Handle DRb connection failures gracefully with descriptive error messages - [ ] Docs: Update experiments Runner documentation with DRb connection details - [ ] Tests (Cucumber): Add `tests/unit/drb_client.feature` covering connection establishment, retry logic, timeout handling, and error scenarios. - [ ] Tests (Cucumber Integration): Add integration feature in `tests/integration/` for DRb client server connectivity. - [ ] Tests (Profiling): Run `bundle exec rake unit_profile` and verify no performance regressions for DRb connection handling. - [ ] Quality: Verify coverage >=85% via `bundle exec rake unit`. If coverage is <85% then review the current unit test coverage report at `build/tests/unit/coverage/` and use it to write new Cucumber based unit tests to improve code coverage. Specifically, write Cucumber/Gherkin style unit tests that are descriptively named and specifically improve coverage on whichever file has the most uncovered lines by writing tests that will target the uncovered lines in the report. Once that is done rerun `bundle exec rake unit` to verify all tests pass and coverage is above >=85%. Only mark this as complete once coverage is >=85%, if not repeat this task as many times as is needed until coverage reaches >=85%. - [ ] Quality: Run `bundle exec rake` (default task: unit tests with coverage) and `bundle exec rake integration`, fix any errors if needed ensuring both pass across **entire** code base, do not ignore any failure even if it seems unrelated to this commit, fix it. ## Definition of Done This issue is complete when: - All subtasks above are completed and checked off. - A Git commit is created where the **first line** of the commit message matches the Commit Message in Metadata exactly, followed by a blank line, then additional lines providing relevant details about the implementation. - The commit is pushed to the remote on the branch matching the **Branch** in Metadata exactly. - The commit is submitted as a **pull request** to `master`, reviewed, and **merged** before this issue is marked done.

freemo commented

2026-03-14 23:57:27 +00:00

Owner

Metadata

Commit Message: feat(experiments): implement DRb client connection
Branch: feature/m3-drb-client

Background and Context

The Runner's attach_to_running_server checks if $manager is non-nil and spawn_ephemeral_server polls $manager in the parent process. Neither approach works because the DRb client connection is never actually established. A proper DRb client connection with retry logic and failure handling is needed.

Expected Behavior

Attach mode connects via DRbObject.new_with_uri('drbunix:tmp/aethyr.drb'). Spawn mode forks, waits for the DRb socket file, then connects. Both modes have timeout handling with clear error messages on failure.

Acceptance Criteria

attach_to_running_server uses DRb connection via DRbObject.new_with_uri
spawn_ephemeral_server forks and waits for DRb socket before connecting
Connection retry with configurable timeout implemented
Clear error messages on DRb connection failure
All existing tests continue to pass

Subtasks

Code: Add DRb client logic to experiments Runner with DRbObject.new_with_uri connection
Code: Implement connection retry with timeout in attach mode
Code: Handle DRb connection failures gracefully with descriptive error messages
Docs: Update experiments Runner documentation with DRb connection details
Tests (Cucumber): Add tests/unit/drb_client.feature covering connection establishment, retry logic, timeout handling, and error scenarios.
Tests (Cucumber Integration): Add integration feature in tests/integration/ for DRb client server connectivity.
Tests (Profiling): Run bundle exec rake unit_profile and verify no performance regressions for DRb connection handling.
Quality: Verify coverage >=85% via bundle exec rake unit. If coverage is <85% then review the current unit test coverage report at build/tests/unit/coverage/ and use it to write new Cucumber based unit tests to improve code coverage. Specifically, write Cucumber/Gherkin style unit tests that are descriptively named and specifically improve coverage on whichever file has the most uncovered lines by writing tests that will target the uncovered lines in the report. Once that is done rerun bundle exec rake unit to verify all tests pass and coverage is above >=85%. Only mark this as complete once coverage is >=85%, if not repeat this task as many times as is needed until coverage reaches >=85%.
Quality: Run bundle exec rake (default task: unit tests with coverage) and bundle exec rake integration, fix any errors if needed ensuring both pass across entire code base, do not ignore any failure even if it seems unrelated to this commit, fix it.

Definition of Done

This issue is complete when:

All subtasks above are completed and checked off.
A Git commit is created where the first line of the commit message matches the Commit Message in Metadata exactly, followed by a blank line, then additional lines providing relevant details about the implementation.
The commit is pushed to the remote on the branch matching the Branch in Metadata exactly.
The commit is submitted as a pull request to master, reviewed, and merged before this issue is marked done.