Class: RailsOtelContext::ActiveRecordContext::Subscriber

Inherits:
Object
  • Object
show all
Defined in:
lib/rails_otel_context/activerecord_context.rb

Overview

Subscriber for sql.active_record notifications.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Subscriber

Returns a new instance of Subscriber.



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# File 'lib/rails_otel_context/activerecord_context.rb', line 84

def initialize
  @threshold = RailsOtelContext.configuration.slow_query_threshold_ms
end

Instance Method Details

#finish(_name, id, _payload) ⇒ Object 



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# File 'lib/rails_otel_context/activerecord_context.rb', line 126

def finish(_name, id, _payload)
  if @threshold && Thread.current[TIMING_ID_KEY].equal?(id)
    elapsed_ms = (Process.clock_gettime(Process::CLOCK_MONOTONIC) - Thread.current[TIMING_START_KEY]) * 1000
    Thread.current[TIMING_ID_KEY] = nil
    if elapsed_ms >= @threshold
      span = OpenTelemetry::Trace.current_span
      span.set_attribute(DB_SLOW_ATTR, true) if span.context.valid?
    end
  end
ensure
  Thread.current[THREAD_KEY] = nil
end

#start(_name, id, payload) ⇒ Object 



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# File 'lib/rails_otel_context/activerecord_context.rb', line 88

def start(_name, id, payload)
  ar_name = payload[:name]
  return unless ar_name
  return if ar_name == 'SCHEMA' || ar_name.start_with?('CACHE')

  ctx = if ar_name == 'SQL'
          ActiveRecordContext.parse_sql_context(payload[:sql])
        else
          ActiveRecordContext.parse_ar_name(ar_name)
        end
  return unless ctx

  # Include scope name if one was captured by RelationScopeCapture
  scope = Thread.current[SCOPE_THREAD_KEY]
  ctx[:scope_name] = scope if scope

  query_key = ctx[:query_key]
  counts = (Thread.current[RequestContext::QUERY_COUNT_KEY] ||= {})
  count = (counts[query_key] = (counts[query_key] || 0) + 1)
  ctx[:query_count] = count if count > 1

  ctx[:async] = true if payload[:async]
  Thread.current[THREAD_KEY] = ctx

  if @threshold
    Thread.current[TIMING_ID_KEY]    = id
    Thread.current[TIMING_START_KEY] = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  end

  # Enrich the current span directly. When OTel instruments via driver-level
  # prepend (Trilogy, PG, Mysql2), the span is created BEFORE this notification
  # fires, so CallContextProcessor#on_start sees nil AR context. Applying here
  # fixes those spans after the fact.
  return unless defined?(OpenTelemetry::Trace)

  ActiveRecordContext.apply_to_span(OpenTelemetry::Trace.current_span, ctx)
end