DOLPHIN/prod/services/ARCHITECTURE_CHOICE.md

Service Architecture Options

Option 1: Single Supervisor (Recommended for You)

One systemd service → Manages multiple internal components

dolphin-supervisor.service
├── ExF Component (thread)
├── OB Component (thread)
├── Watchdog Component (thread)
└── MC Component (thread)

Pros:

• One systemd unit to manage
• Components share memory efficiently
• Centralized health monitoring
• Built-in restart per component
• Lower system overhead

Cons:

• Single process (if it crashes, all components stop)
• Less isolation between components

Use when: Components are tightly coupled, share data

Commands:

systemctl --user start dolphin-supervisor
journalctl --user -u dolphin-supervisor -f

---

Option 2: Multiple Separate Services

Each component = separate systemd service

dolphin-exf.service
├── ExF Component

dolphin-ob.service
├── OB Component

dolphin-watchdog.service
├── Watchdog Component

Pros:

• Full isolation between components
• Independent restart/failure domains
• Can set different resource limits per service
• Systemd handles everything

Cons:

• More systemd units to manage
• Higher memory overhead (separate processes)
• IPC needed for shared data

Use when: Components are independent, need strong isolation

Commands:

./service_manager.py start
./service_manager.py status

---

Option 3: Hybrid (Single Supervisor + Critical Services Separate)

dolphin-supervisor.service
├── ExF Component
├── OB Component
└── MC Component (scheduled)

dolphin-watchdog.service (separate - critical!)
└── Watchdog Component

Use when: One component is critical/safety-related

---

Recommendation

For your Dolphin system, Option 1 (Single Supervisor) is likely best because:

1. Tight coupling: ExF, OB, Watchdog all need Hazelcast
2. Data sharing: Components share state via memory
3. Simplicity: One command to start/stop everything
4. Resource efficiency: Lower overhead than separate processes

The supervisor handles:

• Auto-restart of failed components
• Health monitoring
• Structured logging
• Graceful shutdown

---

Quick Start: Single Supervisor

# 1. Enable and start
cd /mnt/dolphinng5_predict/prod/services
systemctl --user enable dolphin-supervisor
systemctl --user start dolphin-supervisor

# 2. Check status
systemctl --user status dolphin-supervisor

# 3. View logs
journalctl --user -u dolphin-supervisor -f

# 4. Stop
systemctl --user stop dolphin-supervisor