How It Works

Architecture

The SDK runs two background services inside your application:

Your App starts
    │
    ├── ServiceRegistrationHostedService
    │   └── POST /api/services/register
    │       → Returns InstanceId
    │
    └── HeartbeatBackgroundService (loop)
        └── POST /api/services/heartbeat
            → Sends InstanceId + metrics every 30s

Registration Flow

1. Your application starts and AddHubMon() configures the SDK
2. ServiceRegistrationHostedService runs on startup
3. The SDK auto-detects hostname, port, and URL
4. Sends a POST /api/services/register request with service metadata
5. HubMon returns a unique InstanceId

Heartbeat Flow

1. HeartbeatBackgroundService waits for registration to complete (up to 30s)
2. Once registered, it enters a loop at the configured interval (default: 30s)
3. Each heartbeat includes:
   • Instance ID
   • Timestamp
   • System metrics (if enabled)
   • Request tracking data (if enabled)
4. If a heartbeat fails, it retries with exponential backoff

Status Detection

HubMon determines service status based on heartbeats:

Condition	Status
Heartbeat received within expected interval	Healthy
Heartbeat delayed (1-2 missed intervals)	Degraded
No heartbeat for 2+ minutes	Down
Heartbeat resumes after being down	Recovered

When a service goes down, HubMon automatically creates an incident and sends notifications to configured channels (Slack, Discord, email, etc.).