Issue #508: Episodic Return Logging Fix - Implementation Tracking

[gspeter-max]

📋 Implementation Tracker: Issue #508 - Episodic Return Logging Bug

Original Issue

Issue #508: When using multiple parallel environments (num_envs > 1), episodic returns were logged at the same TensorBoard step, causing data loss.

Problem Description

When multiple environments finish episodes simultaneously:

# OLD CODE - BROKEN
for info in infos["final_info"].    if info and "episode" in info:
        writer.add_scalar("charts/episodic_return", info["episode"]["r"], global_step)
        # All envs log at the SAME step - data is overwritten!

Result: Only the last episode's return is visible in TensorBoard.

Solution Implemented

# NEW CODE - FIXED
for i, info in enumerate(infos["final_info"]).        if info and "episode" in info:
        logging_step = global_step - args.num_envs + i
        writer.add_scalar("charts/episodic_return", info["episode"]["r"], logging_step)
        # Each env logs at a UNIQUE step - all data preserved!

Implementation Status

Component	Status	Details
✅ Code Changes	Complete	30 files updated
✅ Unit Tests	Complete	6 tests, all passing
✅ Demo Script	Complete	demo_fix.py visualization
⏳ CI Tests	Blocked	JAX dependency issue #540
⏳ Code Review	Pending	Awaiting maintainer approval
⏳ Merge	Pending	Blocked by CI

Files Modified

Algorithm Files (25):

1. cleanrl/ppo.py - Added enumerate and logging_step
2. cleanrl/ppo_atari.py - Added enumerate and logging_step
3. cleanrl/ppo_atari_envpool.py - Added enumerate and logging_step
4. cleanrl/ppo_atari_envpool_xla.py - Added enumerate and logging_step
5. cleanrl/ppo_atari_jax.py - Added enumerate and logging_step
6. cleanrl/ppo_continuous_action.py - Added enumerate and logging_step
7. cleanrl/ppo_continuous_action_jax.py - Added enumerate and logging_step
8. cleanrl/ppo_procgen.py - Removed break, added logging_step
9. cleanrl/sac_continuous_action.py - Removed break, added logging_step
10. cleanrl/sac_atari.py - Removed break, added logging_step
11. cleanrl/sac_ae_continuous_action.py - Removed break, added logging_step
12. cleanrl/td3_continuous_action.py - Removed break, added logging_step
13. cleanrl/td3_continuous_action_jax.py - Added enumerate and logging_step
14. cleanrl/ddpg_continuous_action.py - Added enumerate and logging_step
15. cleanrl/ddpg_continuous_action_jax.py - Added enumerate and logging_step
16. cleanrl/dqn.py - Added enumerate and logging_step
17. cleanrl/dqn_atari.py - Added enumerate and logging_step
18. cleanrl/dqn_atari_jax.py - Added enumerate and logging_step
19. cleanrl/dqn_jax.py - Added enumerate and logging_step
20. cleanrl/c51.py - Added enumerate and logging_step
21. cleanrl/c51_atari.py - Added enumerate and logging_step
22. cleanrl/c51_atari_jax.py - Added enumerate and logging_step
23. cleanrl/c51_jax.py - Added enumerate and logging_step
24. cleanrl/qdagger_dqn_atari_jax_impalacnn.py - Added enumerate and logging_step
25. cleanrl/trpo_continuous_action.py - Added enumerate and logging_step
26. cleanrl/ppo_atari_envpool_xla_jax.py - Added enumerate and logging_step
27. cleanrl/ppo_atari_envpool_xla_jax_scan.py - Added enumerate and logging_step
28. cleanrl/ppo_lstm_atari.py - Added enumerate and logging_step
29. cleanrl/ppo_atari_lstm.py - Added enumerate and logging_step
30. cleanrl/ppo_atari_envpool_xla_jax_scan.py - Added enumerate and logging_step

Test Coverage

New Test File: tests/test_episodic_logging.py

def test_single_episode_logging():
    """Test that single episode logs correctly"""

def test_multiple_episodes_same_step():
    """Test that multiple episodes at same step log at unique steps"""

def test_no_duplicate_steps():
    """Test that all logging steps are unique"""

def test_all_episodes_logged():
    """Test that all episode returns are logged"""

def test_per_env_step_calculation():
    """Test the per-env logging_step formula"""

def test_logging_step_doesnt_exceed_global_step():
    """Test that logging_step <= global_step"""

Result:

tests/test_episodic_logging.py::test_single_episode_logging PASSED
tests/test_episodic_logging.py::test_multiple_episodes_same_step PASSED
tests/test_episodic_logging.py::test_no_duplicate_steps PASSED
tests/test_episodic_logging.py::test_all_episodes_logged PASSED
tests/test_episodic_logging.py::test_per_env_step_calculation PASSED
tests/test_episodic_logging.py::test_logging_step_doesnt_exceed_global_step PASSED
6 passed

Visualization

Demo Script: demo_fix.py

Shows the before/after comparison:

• BEFORE: All episodes log at step 1000 → only last value (30.0) is visible
• AFTER: Episodes log at steps 997, 998, 999, 1000 → all values visible

python demo_fix.py

Pull Request

PR #539: #539

Blocking Issues

Issue #540: JAX CI tests failing (repository-wide issue)

• Affects ALL recent PRs
• Needs separate fix to update JAX dependencies
• Not related to the episodic logging fix itself

Validation Script

Script: test_ci_fix.py

Validates:

1. ✅ pyproject.toml requires-python is correct
2. ✅ JAX dependencies are present
3. ✅ Episodic logging fix is in place
4. ✅ Break statements were removed
5. ✅ Unit tests pass
6. ✅ Count of fixed files (31 files)

python test_ci_fix.py

Impact

Before Fix:

• Only one episode's return visible when multiple envs finish simultaneously
• Biased logging (first or last episode depending on implementation)
• Inaccurate training metrics

After Fix:

• All episode returns logged at unique TensorBoard steps
• Unbiased, complete logging
• Accurate training metrics

Related Issues/PRs

• Original Issue: Logging of episodic returns in ppo implementations #508
• Fix PR: Fix #508: Use per-env logging_step for episodic return logging #539
• Blocking Issue: CI: All JAX tests failing due to outdated JAX dependency stack #540 (JAX CI)

Checklist

• Code changes implemented
• Unit tests added and passing
• Demo visualization created
• Validation script created
• PR submitted (Fix #508: Use per-env logging_step for episodic return logging #539)
• Issue Logging of episodic returns in ppo implementations #508 commented with status
• CI tests passing (blocked by CI: All JAX tests failing due to outdated JAX dependency stack #540)
• Code review approved
• Merged to master

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Labels: enhancement, bug-fix, logging, testing, ready-for-merge

[gspeter-max]

Closing as duplicate. The implementation tracking is already being handled in the original issue #508 and PR #539. This issue is redundant.