Class: Ask::Observability::Metrics

Inherits:
Object
  • Object
show all
Defined in:
lib/ask/observability/metrics.rb

Overview

Prometheus metric definitions for ask-instrumentation events.

Created lazily on a registry so gems/apps that never emit events don't pay for registry entries, and so tests can inject a fresh registry. The label set is fixed at creation (prometheus-client requires stable label keys per metric) — hence the metadata keys must be configured before the metrics are first touched.

Constant Summary collapse

BASE_LABELS =

Label keys every metric carries.

%i[provider model kind].freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(registry, metadata_label_keys: []) ⇒ Metrics

Returns a new instance of Metrics.



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# File 'lib/ask/observability/metrics.rb', line 33

def initialize(registry, metadata_label_keys: [])
  @registry = registry
  @metadata_label_keys = metadata_label_keys
end

Class Method Details

.for(registry, metadata_label_keys: []) ⇒ Object

Memoized per (registry, metadata keys) pair.



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# File 'lib/ask/observability/metrics.rb', line 18

def for(registry, metadata_label_keys: [])
  instances[[registry.object_id, metadata_label_keys]] ||=
    new(registry, metadata_label_keys: metadata_label_keys)
end

.instances ⇒ Object 



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# File 'lib/ask/observability/metrics.rb', line 23

def instances
  @instances ||= {}
end

.reset! ⇒ Object

For tests: forget every Metrics instance (fresh registries).



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# File 'lib/ask/observability/metrics.rb', line 28

def reset!
  instances.clear
end

Instance Method Details

#calls_total ⇒ Object

ask_llm_calls_totalprovider,model,kind



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# File 'lib/ask/observability/metrics.rb', line 39

def calls_total
  @calls_total ||= @registry.counter(
    :ask_llm_calls_total,
    docstring: 'LLM calls by provider, model, and kind',
    labels: label_keys(:provider, :model, :kind)
  )
end

#duration_seconds ⇒ Object

ask_llm_duration_secondsprovider,model,kind



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# File 'lib/ask/observability/metrics.rb', line 57

def duration_seconds
  @duration_seconds ||= @registry.histogram(
    :ask_llm_duration_seconds,
    docstring: 'LLM call duration in seconds',
    labels: label_keys(:provider, :model, :kind),
    buckets: [0.1, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64]
  )
end

#errors_total ⇒ Object

ask_llm_errors_totalprovider,kind



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# File 'lib/ask/observability/metrics.rb', line 67

def errors_total
  @errors_total ||= @registry.counter(
    :ask_llm_errors_total,
    docstring: 'LLM calls that errored',
    labels: label_keys(:provider, :kind)
  )
end

#tokens_total ⇒ Object

ask_llm_tokens_totalprovider,model,kind,direction



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# File 'lib/ask/observability/metrics.rb', line 48

def tokens_total
  @tokens_total ||= @registry.counter(
    :ask_llm_tokens_total,
    docstring: 'LLM tokens by provider, model, kind, and direction',
    labels: label_keys(:provider, :model, :kind, :direction)
  )
end