# Systemd service for Celery ML model workers.
#
# Separate from crop-ai-api.service deliberately — see
# docs/architecture.md for why web serving and ML compute are split
# into independent process groups that scale independently.
#
# Install: sudo cp this file to /etc/systemd/system/crop-ai-worker.service
# then:
#   sudo systemctl daemon-reload
#   sudo systemctl enable crop-ai-worker
#   sudo systemctl start crop-ai-worker
#
# Logs: journalctl -u crop-ai-worker -f

[Unit]
Description=AI Crop Decision Support System - Celery ML model workers
After=network.target postgresql.service redis-server.service crop-ai-api.service
Wants=postgresql.service redis-server.service

[Service]
Type=simple
User=cropai
Group=cropai
WorkingDirectory=/opt/crop-ai-system
EnvironmentFile=/opt/crop-ai-system/.env

# --concurrency controls how many tasks run in parallel per worker
# process. Each loaded model set (6 models, ~tens of MB combined for
# the tree-based models, SARIMAX dicts scale with district/crop-pair
# count) lives once per process — concurrency=2 is a safe starting
# point for a modest VPS; raise it once you've measured actual memory
# headroom under load.
ExecStart=/opt/crop-ai-system/venv/bin/celery -A app.workers.celery_app worker \
    --loglevel=info \
    --concurrency=2 \
    --max-tasks-per-child=200 \
    --logfile=/opt/crop-ai-system/logs/celery-worker.log

Restart=on-failure
RestartSec=5

NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=strict
ReadWritePaths=/opt/crop-ai-system/logs

[Install]
WantedBy=multi-user.target