groups:

- name: RubyExporter

  
  rules:

    # Threshold is a rough default. Adjust based on your application's normal heap size.
    - alert: RubyHeapLiveSlotsHigh
      expr: 'ruby_heap_live_slots > 500000'
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: Ruby heap live slots high (instance {{ $labels.instance }})
        description: "Ruby heap has too many live slots (> 500k), heap bloat\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    - alert: RubyHeapFreeSlotsHigh
      expr: 'ruby_heap_free_slots > 500000'
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: Ruby heap free slots high (instance {{ $labels.instance }})
        description: "Ruby heap has too many free slots (> 500k), memory fragmentation after large allocations\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    # Major GC rate > 5/s only fires if the app is essentially non-functional. Threshold of 2/s provides earlier detection.
    - alert: RubyMajorGcRateHigh
      expr: 'rate(ruby_major_gc_ops_total[5m]) > 2'
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: Ruby major GC rate high (instance {{ $labels.instance }})
        description: "Ruby is performing too many major GC cycles, indicating memory pressure\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    - alert: RubyRssHigh
      expr: 'ruby_rss > 1e9'
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: Ruby RSS high (instance {{ $labels.instance }})
        description: "Ruby process RSS is high (> 1GB)\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    - alert: RubyAllocatedObjectsSpike
      expr: 'rate(ruby_allocated_objects_total[5m]) > 100000'
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: Ruby allocated objects spike (instance {{ $labels.instance }})
        description: "Ruby is allocating objects at a high rate\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"