Class: StatsD::Instrument::Aggregator

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

Constant Summary collapse

CONST_SAMPLE_RATE = 
1.0
COUNT = 
:c
DISTRIBUTION = 
:d
MEASURE = 
:ms
HISTOGRAM = 
:h
GAUGE = 
:g

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sink, datagram_builder_class, prefix, default_tags, flush_interval: 5.0, max_values: 100) ⇒ 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: 100) —

    The maximum number of values to aggregate before flushing.



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# File 'lib/statsd/instrument/aggregator.rb', line 81

def initialize(sink, datagram_builder_class, prefix, default_tags, flush_interval: 5.0, max_values: 100)
  @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
  @mutex = Mutex.new
  @aggregation_state = {}

  @pid = Process.pid
  @flush_interval = flush_interval
  @flush_thread = Thread.new do
    Thread.current.abort_on_exception = true
    loop do
      sleep(@flush_interval)
      thread_healthcheck
      flush
    rescue => e
      StatsD.logger.error { "[#{self.class.name}] Error in flush thread: #{e}" }
      raise e
    end
  end

  ObjectSpace.define_finalizer(
    self,
    self.class.finalize(@aggregation_state, @sink, @datagram_builders, @datagram_builder_class, @default_tags),
  )
end

Class Method Details

.finalize(aggregation_state, sink, datagram_builders, datagram_builder_class, default_tags) ⇒ Object 



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# File 'lib/statsd/instrument/aggregator.rb', line 35

def finalize(aggregation_state, sink, datagram_builders, datagram_builder_class, default_tags)
  proc do
    aggregation_state.each do |key, agg_value|
      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,
          CONST_SAMPLE_RATE,
          key.tags,
        )
      when DISTRIBUTION, MEASURE, HISTOGRAM
        sink << datagram_builders[no_prefix].timing_value_packed(
          key.name,
          key.type.to_s,
          agg_value,
          CONST_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
    aggregation_state.clear
  end
end

Instance Method Details

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



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# File 'lib/statsd/instrument/aggregator.rb', line 137

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

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

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

#flush ⇒ Object 



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

def flush
  @mutex.synchronize { do_flush }
end

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



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# File 'lib/statsd/instrument/aggregator.rb', line 157

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)

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

#increment(name, value = 1, tags: [], no_prefix: false) ⇒ 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 122

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

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

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