What

Implement system uptime monitoring to track boot time and system availability.

• Current: No uptime tracking exists
• Expected: Boot timestamp, uptime duration, and availability metrics
• Scope: Cross-platform implementation (Linux, macOS, Windows)

Why

• Problem: Cannot track system stability or calculate availability SLOs
• Impact: No visibility into unexpected reboots or system restarts
• Value: Enables availability monitoring, SLA compliance tracking, stability analysis
• Priority: Low - Simple to implement, useful for all environments

Where

• Files: src/platform/linux_metrics.cpp, src/platform/windows_metrics.cpp, src/platform/macos_metrics.cpp
• Integration: system_resource_collector.h (can extend existing collector)
• Environment: All platforms
• Related: system_resource_collector

How

Technical Approach

1. Extend system_resource_collector or create standalone uptime_collector
2. Platform-specific implementations:
   • Linux: Read /proc/uptime or use sysinfo() syscall
   • macOS: Use sysctl(KERN_BOOTTIME)
   • Windows: Use GetTickCount64() or QueryPerformanceCounter()
3. Metrics to collect:
   • system_uptime_seconds: Time since boot
   • system_boot_timestamp: Unix timestamp of last boot
   • system_boot_count: (if available) Number of boots since install

Acceptance Criteria

• Uptime metrics available on Linux via /proc/uptime
• Uptime metrics available on macOS via sysctl
• Uptime metrics available on Windows via GetTickCount64
• Returns system_uptime_seconds (gauge)
• Returns system_boot_timestamp (gauge)
• Unit tests for each platform
• Documentation updated

Platform APIs Reference

Size Estimate

size/S - Straightforward implementation using well-documented OS APIs