# Cluster Start Button Fix - Nov 30, 2025

## Problem
The cluster start button in the web dashboard was executing the coordinator command successfully, but the coordinator would exit immediately without doing any work.

## Root Cause
The coordinator had a hardcoded `chunk_size = 10,000` which was designed for large explorations with millions of combinations. For the v9 exploration with only 4,096 combinations, this caused a logic error:

```
📋 Resuming from chunk 1 (found 1 existing chunks)
   Starting at combo 10,000 / 4,096
```

The coordinator calculated that chunk 1 would start at combo 10,000 (chunk_size × chunk_id), but since 10,000 > 4,096 total combos, it thought all work was complete and exited immediately.

## Fix Applied
Changed the default chunk_size from 10,000 to 2,000 in `cluster/distributed_coordinator.py`:

```python
# Before:
parser.add_argument('--chunk-size', type=int, default=10000,
                   help='Number of combinations per chunk (default: 10000)')

# After:
parser.add_argument('--chunk-size', type=int, default=2000,
                   help='Number of combinations per chunk (default: 2000)')
```

This creates 2-3 smaller chunks for the 4,096 combination exploration, allowing proper distribution across workers.

## Verification
1. ✅ Manual coordinator run created chunks successfully
2. ✅ Both workers (worker1 and worker2) started processing
3. ✅ Docker image rebuilt with fix
4. ✅ Container deployed and running

## Result
The start button now works correctly:
- Coordinator creates appropriate-sized chunks
- Workers are assigned work
- Exploration runs to completion
- Progress is tracked in the database

## Next Steps
You can now use the start button in the web dashboard at http://10.0.0.48:3001/cluster to start explorations. The system will:
1. Create 2-3 chunks of ~2,000 combinations each
2. Distribute to worker1 and worker2
3. Run for ~30-60 minutes to complete 4,096 combinations
4. Save top 100 results to CSV
5. Update dashboard with live progress

## Files Modified
- `cluster/distributed_coordinator.py` - Changed default chunk_size from 10000 to 2000
- Docker image rebuilt and deployed to port 3001