Class: StatsD::Instrument::Aggregator

Inherits:
Object
  • Object
show all
Defined in:
lib/statsd/instrument/aggregator.rb

Defined Under Namespace

Classes: Finalizer

Constant Summary collapse

DEFAULT_MAX_CONTEXT_SIZE = 
250

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sink, datagram_builder_class, prefix, default_tags, flush_interval: 5.0, max_values: DEFAULT_MAX_CONTEXT_SIZE) ⇒ Aggregator

Returns a new instance of Aggregator.

Parameters:

  • sink (#<<) —

    The sink to write the aggregated metrics to.

  • datagram_builder_class (Class) —

    The class to use for building datagrams.

  • prefix (String) —

    The prefix to add to all metrics.

  • default_tags (Array<String>) —

    The tags to add to all metrics.

  • flush_interval (Float) (defaults to: 5.0) —

    The interval at which to flush the aggregated metrics.

  • max_values (Integer) (defaults to: DEFAULT_MAX_CONTEXT_SIZE) —

    The maximum number of values to aggregate before flushing.



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# File 'lib/statsd/instrument/aggregator.rb', line 101

def initialize(
  sink,
  datagram_builder_class,
  prefix,
  default_tags,
  flush_interval: 5.0,
  max_values: DEFAULT_MAX_CONTEXT_SIZE
)
  @sink = sink
  @datagram_builder_class = datagram_builder_class
  @metric_prefix = prefix
  @default_tags = default_tags
  @datagram_builders = {
    true: nil,
    false: nil,
  }
  @max_values = max_values

  # Mutex protects the aggregation_state and flush_thread from concurrent access
  @aggregation_state_mutex = Mutex.new
  # Mutex protects do_flush to prevent flushing to the sink concurrently
  @flush_mutex = Mutex.new

  @aggregation_state = {}

  @pid = Process.pid
  @flush_interval = flush_interval
  start_flush_thread

  @finalizer = Finalizer.new(
    @aggregation_state,
    @sink,
    @datagram_builders,
    @datagram_builder_class,
    @default_tags,
    @metric_prefix,
  )

  ObjectSpace.define_finalizer(
    self,
    self.class.finalize(@finalizer),
  )
end

Class Method Details

.finalize(finalizer) ⇒ Object 



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# File 'lib/statsd/instrument/aggregator.rb', line 43

def finalize(finalizer)
  # The finalizer can be called in trap context, which means we cannot use mutexes here.
  proc do
    aggregation_state = finalizer.aggregation_state
    sink = finalizer.sink
    datagram_builders = finalizer.datagram_builders
    datagram_builder_class = finalizer.datagram_builder_class
    default_tags = finalizer.default_tags
    metric_prefix = finalizer.metric_prefix

    aggregation_state.each do |key, agg_value|
      if key.is_a?(StatsD::Instrument::CompiledMetric::PrecompiledDatagram)
        sink << key.to_datagram(agg_value)
        next
      end

      no_prefix = key.no_prefix
      datagram_builders[no_prefix] ||= datagram_builder_class.new(
        prefix: no_prefix ? nil : metric_prefix,
        default_tags: default_tags,
      )
      case key.type
      when COUNT
        sink << datagram_builders[no_prefix].c(
          key.name,
          agg_value,
          key.sample_rate,
          key.tags,
        )
      when DISTRIBUTION, MEASURE, HISTOGRAM
        sink << datagram_builders[no_prefix].timing_value_packed(
          key.name,
          key.type.to_s,
          agg_value,
          key.sample_rate,
          key.tags,
        )
      when GAUGE
        sink << datagram_builders[no_prefix].g(
          key.name,
          agg_value,
          CONST_SAMPLE_RATE,
          key.tags,
        )
      else
        StatsD.logger.error { "[#{self.class.name}] Unknown aggregation type: #{key.type}" }
      end
    end
  end
end

Instance Method Details

#aggregate_precompiled_gauge_metric(precompiled_datagram, value) ⇒ void

This method returns an undefined value.

Aggregates a precompiled metric that can be combined into a single scalar for later flushing.

Parameters:



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# File 'lib/statsd/instrument/aggregator.rb', line 215

def aggregate_precompiled_gauge_metric(precompiled_datagram, value)
  unless thread_healthcheck
    # Fallback: emit directly if thread is unhealthy
    @sink << precompiled_datagram.to_datagram(value)
    return
  end

  @aggregation_state_mutex.synchronize do
    @aggregation_state[precompiled_datagram] = value
  end
end

#aggregate_precompiled_increment_metric(precompiled_datagram, value = 1) ⇒ void

This method returns an undefined value.

Aggregates a precompiled metric that can be combined into a single scalar for later flushing.

Parameters:



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# File 'lib/statsd/instrument/aggregator.rb', line 171

def aggregate_precompiled_increment_metric(precompiled_datagram, value = 1)
  unless thread_healthcheck
    # Fallback: emit directly if thread is unhealthy
    @sink << precompiled_datagram.to_datagram(value)
    return
  end

  @aggregation_state_mutex.synchronize do
    @aggregation_state[precompiled_datagram] ||= 0
    @aggregation_state[precompiled_datagram] += value
  end
end

#aggregate_precompiled_timing_metric(precompiled_datagram, value = 1) ⇒ void

This method returns an undefined value.

Aggregates a precompiled metric that can be packed into a single datagram for later flushing.

Parameters:



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# File 'lib/statsd/instrument/aggregator.rb', line 189

def aggregate_precompiled_timing_metric(precompiled_datagram, value = 1)
  unless thread_healthcheck
    # Fallback: emit directly if thread is unhealthy
    @sink << precompiled_datagram.to_datagram(value)
    return
  end

  aggregation_state = nil

  @aggregation_state_mutex.synchronize do
    values = @aggregation_state[precompiled_datagram] ||= []
    if values.size + 1 >= @max_values
      aggregation_state = @aggregation_state
      new_aggregation_state
    end
    values << value
  end

  do_flush(aggregation_state) if aggregation_state
end

#aggregate_timing(name, value, tags: [], no_prefix: false, type: DISTRIBUTION, sample_rate: CONST_SAMPLE_RATE) ⇒ Object 



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# File 'lib/statsd/instrument/aggregator.rb', line 227

def aggregate_timing(name, value, tags: [], no_prefix: false, type: DISTRIBUTION, sample_rate: CONST_SAMPLE_RATE)
  unless thread_healthcheck
    @sink << datagram_builder(no_prefix: no_prefix).timing_value_packed(
      name, type.to_s, [value], sample_rate, tags
    )
    return
  end

  tags = tags_sorted(tags)
  key = packet_key(name, tags, no_prefix, type, sample_rate: sample_rate)

  aggregation_state = nil

  @aggregation_state_mutex.synchronize do
    values = @aggregation_state[key] ||= []
    if values.size + 1 >= @max_values
      aggregation_state = @aggregation_state
      new_aggregation_state
    end
    values << value
  end

  do_flush(aggregation_state) if aggregation_state
end

#flush ⇒ Object 



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# File 'lib/statsd/instrument/aggregator.rb', line 266

def flush
  state = nil
  @aggregation_state_mutex.synchronize do
    state = @aggregation_state
    new_aggregation_state
  end

  do_flush(state)
end

#gauge(name, value, tags: [], no_prefix: false) ⇒ Object 



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# File 'lib/statsd/instrument/aggregator.rb', line 252

def gauge(name, value, tags: [], no_prefix: false)
  unless thread_healthcheck
    @sink << datagram_builder(no_prefix: no_prefix).g(name, value, CONST_SAMPLE_RATE, tags)
    return
  end

  tags = tags_sorted(tags)
  key = packet_key(name, tags, no_prefix, GAUGE)

  @aggregation_state_mutex.synchronize do
    @aggregation_state[key] = value
  end
end

#increment(name, value = 1, tags: [], no_prefix: false, sample_rate: CONST_SAMPLE_RATE) ⇒ void

This method returns an undefined value.

Increment a counter by a given value and save it for later flushing.

Parameters:

  • name (String) —

    The name of the counter.

  • value (Integer) (defaults to: 1) —

    The value to increment the counter by.

  • tags (Hash{String, Symbol => String}, Array<String>) (defaults to: []) —

    The tags to attach to the counter.

  • no_prefix (Boolean) (defaults to: false) —

    If true, the metric will not be prefixed.



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# File 'lib/statsd/instrument/aggregator.rb', line 151

def increment(name, value = 1, tags: [], no_prefix: false, sample_rate: CONST_SAMPLE_RATE)
  unless thread_healthcheck
    @sink << datagram_builder(no_prefix: no_prefix).c(name, value, sample_rate, tags)
    return
  end

  tags = tags_sorted(tags)
  key = packet_key(name, tags, no_prefix, COUNT, sample_rate: sample_rate)

  @aggregation_state_mutex.synchronize do
    @aggregation_state[key] ||= 0
    @aggregation_state[key] += value
  end
end