v0.7.0 — Prometheus Metrics

Prometheus Metrics Instrumentation

What's New

• 22 unique hac_ domain metrics covering nodes, tasks, leases, and sync
• API middleware records node registration, heartbeat, task creation, completion, and failure events
• Gauge updaters for nodes, tasks, leases, and sync version
• Duration metrics — task processing time measured from CreatedAt to completion/failure

Metrics Catalog

Metric	Type	Description
hac_nodes_registered_total	counter	Node registration events
hac_heartbeats_received_total	counter	Heartbeat events
hac_tasks_created_total	counter	Task creation events
hac_tasks_completed_total	counter	Task completion events
hac_tasks_failed_total	counter	Task failure events
hac_task_duration_seconds	histogram	Task processing duration
hac_nodes_online	gauge	Currently online nodes
hac_tasks_pending	gauge	Pending tasks
hac_leases_active	gauge	Active leases
hac_sync_version	gauge	Current sync version

Testing

• All 27 metrics tests pass with -race detector
• 11 new integration tests for API instrumentation
• Concurrent access race-clean

Commits

• adbe63c feat: add Prometheus metrics instrumentation to API handlers

Full diff: v0.6.0...v0.7.0