✅ Milestone Completed: Prometheus Data Format Integration

This sprint focused on making telemetry output fully Prometheus-compatible while preserving our existing collector pipeline for CPU, memory, and disk I/O.

What I implemented

• Added Prometheus text exposition format (v0.0.4) output
• Included # HELP and # TYPE metadata
• Supported gauge and counter metric families
• Added label-based dimensions (CPU modes, disk devices)
• Kept output deterministic and scrape-ready for a /metrics style endpoint

Metrics now covered

• CPU usage and per-mode CPU time distribution
• Virtual memory: used, available, total
• Swap memory: used, total
• Disk I/O bytes: read/write (aggregate + per-device)
• Disk I/O operations: read/write (aggregate + per-device)

Validation results

• Output verified against Prometheus exposition rules
• No syntax violations found
• Metrics are parseable and scrape-ready

Prior milestone context (OpenMetrics)

Before this, I shipped OpenMetrics-aligned output for the same core Linux host metrics with:

• # HELP, # TYPE, # UNIT metadata
• # EOF termination
• Valid CPU, memory, and disk payload output

Next improvements

• Evaluate ratio-based CPU values (0–1) vs percentage
• Extend optional unit handling for stronger tooling interoperability
• Continue OpenMetrics alignment where needed

Repo: https://github.com/ronin1770/heka-insights-agent