Class: Fluent::StatsOutput

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ StatsOutput

Returns a new instance of StatsOutput.



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# File 'lib/fluent/plugin/out_stats.rb', line 5

def initialize
  super
  require 'pathname'
end

Instance Attribute Details

#last_checked ⇒ Object

Returns the value of attribute last_checked.



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# File 'lib/fluent/plugin/out_stats.rb', line 33

def last_checked
  @last_checked
end

#matches ⇒ Object

Returns the value of attribute matches.



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# File 'lib/fluent/plugin/out_stats.rb', line 30

def matches
  @matches
end

#saved_at ⇒ Object

Returns the value of attribute saved_at.



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# File 'lib/fluent/plugin/out_stats.rb', line 32

def saved_at
  @saved_at
end

#saved_duration ⇒ Object

Returns the value of attribute saved_duration.



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# File 'lib/fluent/plugin/out_stats.rb', line 31

def saved_duration
  @saved_duration
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 35

def configure(conf)
  super

  @interval = @interval.to_i
  @sum = Regexp.new(@sum) if @sum
  @max = Regexp.new(@max) if @max
  @min = Regexp.new(@min) if @min
  @avg = Regexp.new(@avg) if @avg
  @sum_keys = @sum_keys ? @sum_keys.split(',') : []
  @max_keys = @max_keys ? @max_keys.split(',') : []
  @min_keys = @min_keys ? @min_keys.split(',') : []
  @avg_keys = @avg_keys ? @avg_keys.split(',') : []

  unless ['tag', 'all'].include?(@aggregate)
    raise Fluent::ConfigError, "aggregate allows tag/all"
  end

  case @aggregate
  when 'all'
    raise Fluent::ConfigError, "tag must be specified for aggregate all" if @tag.nil?
  end

  if @tag.nil? and @add_tag_prefix.nil? and @remove_tag_prefix.nil?
    @add_tag_prefix = 'stats' # not ConfigError for lower version compatibility
  end

  @tag_prefix = "#{@add_tag_prefix}." if @add_tag_prefix
  @tag_prefix_match = "#{@remove_tag_prefix}." if @remove_tag_prefix
  @tag_proc =
    if @tag
      Proc.new {|tag| @tag }
    elsif @tag_prefix and @tag_prefix_match
      Proc.new {|tag| "#{@tag_prefix}#{lstrip(tag, @tag_prefix_match)}" }
    elsif @tag_prefix_match
      Proc.new {|tag| lstrip(tag, @tag_prefix_match) }
    elsif @tag_prefix
      Proc.new {|tag| "#{@tag_prefix}#{tag}" }
    else
      Proc.new {|tag| tag }
    end

  @matches = {}
  @mutex = Mutex.new
end

#emit(tag, es, chain) ⇒ Object

Called when new line comes. This method actually does not emit



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# File 'lib/fluent/plugin/out_stats.rb', line 112

def emit(tag, es, chain)
  tag = 'all' if @aggregate == 'all'
  # stats
  matches = { :count => 0, :sum => {}, :max => {}, :min => {}, :avg => {} }
  es.each do |time, record|
    @sum_keys.each do |key|
      next unless record[key] and value = record[key].to_f
      matches[:sum][key] = sum(matches[:sum][key], value)
    end
    @max_keys.each do |key|
      next unless record[key] and value = record[key].to_f
      matches[:max][key] = max(matches[:max][key], value)
    end
    @min_keys.each do |key|
      next unless record[key] and value = record[key].to_f
      matches[:min][key] = min(matches[:min][key], value)
    end
    @avg_keys.each do |key|
      next unless record[key] and value = record[key].to_f
      matches[:avg][key] = sum(matches[:avg][key], value)
    end
    record.keys.each do |key|
      value = record[key].to_f
      if @sum and @sum.match(key)
        matches[:sum][key] = sum(matches[:sum][key], value)
      end
      if @max and @max.match(key)
        matches[:max][key] = max(matches[:max][key], value)
      end
      if @min and @min.match(key)
        matches[:min][key] = min(matches[:min][key], value)
      end
      if @avg and @avg.match(key)
        matches[:avg][key] = sum(matches[:avg][key], value) # sum yet
      end
    end if @sum || @max || @min || @avg
    matches[:count] += 1
  end

  # thread safe merge
  @matches[tag] ||= { :count => 0, :sum => {}, :max => {}, :min => {}, :avg => {} }
  @mutex.synchronize do
    matches[:sum].keys.each do |key|
      @matches[tag][:sum][key] = sum(@matches[tag][:sum][key], matches[:sum][key])
    end
    matches[:max].keys.each do |key|
      @matches[tag][:max][key] = max(@matches[tag][:max][key], matches[:max][key])
    end
    matches[:min].keys.each do |key|
      @matches[tag][:min][key] = min(@matches[tag][:min][key], matches[:min][key])
    end
    matches[:avg].keys.each do |key|
      @matches[tag][:avg][key] = sum(@matches[tag][:avg][key], matches[:avg][key]) # sum yet
    end
    @matches[tag][:count] += matches[:count]
  end

  chain.next
rescue => e
  $log.warn "#{e.class} #{e.message} #{e.backtrace.first}"
end

#flush_emit(step) ⇒ Object

This method is the real one to emit



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# File 'lib/fluent/plugin/out_stats.rb', line 193

def flush_emit(step)
  time = Fluent::Engine.now
  flushed_matches, @matches = @matches, initial_matches(@matches)

  flushed_matches.keys.each do |tag|
    matches = flushed_matches[tag]
    output = generate_output(matches)
    emit_tag = @tag_proc.call(tag)
    Fluent::Engine.emit(emit_tag, time, output) if output and !output.empty?
  end
end

#generate_output(matches) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 205

def generate_output(matches)
  return nil if matches.empty?
  output = {}
  matches[:sum].keys.each do |key|
    output[key + @sum_suffix] = matches[:sum][key]
  end
  matches[:max].keys.each do |key|
    output[key + @max_suffix] = matches[:max][key]
  end
  matches[:min].keys.each do |key|
    output[key + @min_suffix] = matches[:min][key]
  end
  matches[:avg].keys.each do |key|
    output[key + @avg_suffix] = matches[:avg][key]
    output[key + @avg_suffix] /= matches[:count].to_f if matches[:count] > 0
  end
  output
end

#initial_matches(prev_matches = nil) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 80

def initial_matches(prev_matches = nil)
  if @zero_emit && prev_matches
    matches = {}
    prev_matches.keys.each do |tag|
      next unless prev_matches[tag][:count] > 0 # Prohibit to emit anymore
      matches[tag] = { :count => 0, :sum => {}, :max => {}, :min => {}, :avg => {} }
      # ToDo: would want default configuration for :max, :min
      prev_matches[tag][:sum].keys.each {|key| matches[tag][:sum][key] = 0 }
      prev_matches[tag][:max].keys.each {|key| matches[tag][:max][key] = 0 }
      prev_matches[tag][:min].keys.each {|key| matches[tag][:min][key] = 0 }
      prev_matches[tag][:avg].keys.each {|key| matches[tag][:avg][key] = 0 }
    end
    matches
  else
    {}
  end
end

#load_status(file_path, interval) ⇒ Object

Load internal status from a file

Parameters:



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# File 'lib/fluent/plugin/out_stats.rb', line 266

def load_status(file_path, interval)
  return unless (f = Pathname.new(file_path)).exist?

  begin
    f.open('rb') do |f|
      stored = Marshal.load(f)
      if stored[:aggregate] == @aggregate and
        stored[:sum] == @sum and
        stored[:max] == @max and
        stored[:min] == @min and
        stored[:avg] == @avg

        if !stored[:matches].empty? and !stored[:matches].first[1].has_key?(:max)
          $log.warn "out_stats: stored data does not have compatibility with the current version. ignore stored data"
          return
        end

        if Fluent::Engine.now <= stored[:saved_at] + interval
          @matches = stored[:matches]
          @saved_at = stored[:saved_at]
          @saved_duration = stored[:saved_duration]
          # for lower compatibility
          if counts = stored[:counts]
            @matches.keys.each {|tag| @matches[tag][:count] = counts[tag] }
          end

          # skip the saved duration to continue counting
          @last_checked = Fluent::Engine.now - @saved_duration
        else
          $log.warn "out_stats: stored data is outdated. ignore stored data"
        end
      else
        $log.warn "out_stats: configuration param was changed. ignore stored data"
      end
    end
  rescue => e
    $log.warn "out_stats: Can't load store_file #{e.class} #{e.message}"
  end
end

#max(a, b) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 228

def max(a, b)
  [a, b].compact.max
end

#min(a, b) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 232

def min(a, b)
  [a, b].compact.min
end

#save_status(file_path) ⇒ Object

Store internal status into a file

Parameters:



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# File 'lib/fluent/plugin/out_stats.rb', line 239

def save_status(file_path)
  return unless file_path

  begin
    Pathname.new(file_path).open('wb') do |f|
      @saved_at = Fluent::Engine.now
      @saved_duration = @saved_at - @last_checked
      Marshal.dump({
        :matches          => @matches,
        :saved_at         => @saved_at,
        :saved_duration   => @saved_duration,
        :aggregate        => @aggregate,
        :sum              => @sum,
        :max              => @max,
        :min              => @min,
        :avg              => @avg,
      }, f)
    end
  rescue => e
    $log.warn "out_stats: Can't write store_file #{e.class} #{e.message}"
  end
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 104

def shutdown
  super
  @watcher.terminate
  @watcher.join
  save_status(@store_file) if @store_file
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 98

def start
  super
  load_status(@store_file, @interval) if @store_file
  @watcher = Thread.new(&method(:watcher))
end

#sum(a, b) ⇒ Object 



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# File 'lib/fluent/plugin/out_stats.rb', line 224

def sum(a, b)
  [a, b].compact.inject(:+)
end

#watcher ⇒ Object

thread callback



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# File 'lib/fluent/plugin/out_stats.rb', line 175

def watcher
  # instance variable, and public accessable, for test
  @last_checked ||= Fluent::Engine.now
  while true
    sleep 0.5
    begin
      if Fluent::Engine.now - @last_checked >= @interval
        now = Fluent::Engine.now
        flush_emit(now - @last_checked)
        @last_checked = now
      end
    rescue => e
      $log.warn "#{e.class} #{e.message} #{e.backtrace.first}"
    end
  end
end