Class: Fluent::SamplingFilterOutput

Inherits:
Output
  • Object
show all
Defined in:
lib/fluent/plugin/out_sampling_filter.rb

Instance Method Summary collapse

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_sampling_filter.rb', line 15

def configure(conf)
  super

  if @remove_prefix
    @removed_prefix_string = @remove_prefix + '.'
    @removed_length = @removed_prefix_string.length
  elsif @add_prefix.empty?
    raise Fluent::ConfigError, "either of 'add_prefix' or 'remove_prefix' must be specified"
  end
  @added_prefix_string = @add_prefix + '.' unless @add_prefix.empty?

  @sample_unit = case @sample_unit
                 when 'tag'
                   :tag
                 when 'all'
                   :all
                 else
                   raise Fluent::ConfigError, "sample_unit allows only 'tag' or 'all'"
                 end
  @counts = {}
  @resets = {} if @minimum_rate_per_min
end

#emit(tag, es, chain) ⇒ Object 



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# File 'lib/fluent/plugin/out_sampling_filter.rb', line 54

def emit(tag, es, chain)
  t = if @sample_unit == :all
        'all'
      else
        tag
      end

  pairs = []

  # Access to @counts SHOULD be protected by mutex, with a heavy penalty.
  # Code below is not thread safe, but @counts (counter for sampling rate) is not
  # so serious value (and probably will not be broken...),
  # then i let here as it is now.
  if @minimum_rate_per_min
    unless @resets[t]
      @resets[t] = Fluent::Engine.now + (60 - rand(30))
    end
    if Fluent::Engine.now > @resets[t]
      @resets[t] = Fluent::Engine.now + 60
      @counts[t] = 0
    end
    es.each do |time,record|
      c = (@counts[t] = @counts.fetch(t, 0) + 1)
      if c < @minimum_rate_per_min or c % @interval == 0
        pairs.push [time, record]
      end
    end
  else
    es.each do |time,record|
      c = (@counts[t] = @counts.fetch(t, 0) + 1)
      if c % @interval == 0
        pairs.push [time, record]
        # reset only just before @counts[t] is to be bignum from fixnum
        @counts[t] = 0 if c > 0x6fffffff
      end
    end
  end

  emit_sampled(tag, pairs)

  chain.next
end

#emit_sampled(tag, time_record_pairs) ⇒ Object 



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# File 'lib/fluent/plugin/out_sampling_filter.rb', line 38

def emit_sampled(tag, time_record_pairs)
  if @remove_prefix and
      ( (tag.start_with?(@removed_prefix_string) and tag.length > @removed_length) or tag == @remove_prefix)
    tag = tag[@removed_length..-1]
  end
  if tag.length > 0
    tag = @added_prefix_string + tag if @added_prefix_string
  else
    tag = @add_prefix
  end

  time_record_pairs.each {|t,r|
    router.emit(tag, t, r)
  }
end