Class: Fluent::GrepCounterOutput

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ GrepCounterOutput

Returns a new instance of GrepCounterOutput.



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

def initialize
  super
  require 'pathname'
end

Instance Attribute Details

#counts ⇒ Object

Returns the value of attribute counts.



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

def counts
  @counts
end

#last_checked ⇒ Object

Returns the value of attribute last_checked.



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 34

def last_checked
  @last_checked
end

#matches ⇒ Object

Returns the value of attribute matches.



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

def matches
  @matches
end

#saved_at ⇒ Object

Returns the value of attribute saved_at.



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

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_grepcounter.rb', line 32

def saved_duration
  @saved_duration
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 36

def configure(conf)
  super

  @count_interval = @count_interval.to_i
  @input_key = @input_key.to_s
  @regexp = Regexp.compile(@regexp) if @regexp
  @exclude = Regexp.compile(@exclude) if @exclude

  @threshold = @threshold.to_i if @threshold

  unless ['>=', '<='].include?(@comparator)
    raise Fluent::ConfigError, "grepcounter: comparator allows >=, <="
  end

  # to support obsolete `threshold` and `comparator` options
  if @threshold.nil? and @less_than.nil? and @less_equal.nil? and @greater_than.nil? and @greater_equal.nil?
    @threshold = 1
  end
  if @threshold and @comparator
    if @comparator == '>='
      @greater_equal = @threshold
    else
      @less_equal = @threshold
    end
  end

  # to support osolete `output_tag` option
  @tag = @output_tag if !@tag and @output_tag

  # to support obsolete `output_with_joined_delimiter` option
  @delimiter = @output_with_joined_delimiter if !@delimiter and @output_with_joined_delimiter

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

  case @aggregate
  when 'all'
    raise Fluent::ConfigError, "grepcounter: output_tag must be specified with aggregate all" if @output_tag.nil?
  when 'tag'
    # raise Fluent::ConfigError, "grepcounter: add_tag_prefix must be specified with aggregate tag" if @add_tag_prefix.nil?
  end

  if @store_file
    f = Pathname.new(@store_file)
    if (f.exist? && !f.writable_real?) || (!f.exist? && !f.parent.writable_real?)
      raise Fluent::ConfigError, "#{@store_file} is not writable"
    end
  end

  if @tag.nil? and @add_tag_prefix.nil? and @remove_tag_prefix.nil?
    @add_tag_prefix = 'count' # not ConfigError to support 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 = {}
  @counts  = {}
  @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_grepcounter.rb', line 124

def emit(tag, es, chain)
  count = 0; matches = []
  # filter out and insert
  es.each do |time,record|
    value = record[@input_key]
    next unless match(value.to_s)
    matches << value
    count += 1
  end
  # thread safe merge
  @counts[tag] ||= 0
  @matches[tag] ||= []
  @mutex.synchronize do
    @counts[tag] += count
    @matches[tag] += matches
  end

  chain.next
rescue => e
  $log.warn "grepcounter: #{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_grepcounter.rb', line 165

def flush_emit(step)
  time = Fluent::Engine.now
  flushed_counts, flushed_matches, @counts, @matches = @counts, @matches, {}, {}

  if @aggregate == 'all'
    count = 0; matches = []
    flushed_counts.keys.each do |tag|
      count += flushed_counts[tag]
      matches += flushed_matches[tag]
    end
    output = generate_output(count, matches)
    Fluent::Engine.emit(@tag, time, output) if output
  else
    flushed_counts.keys.each do |tag|
      count = flushed_counts[tag]
      matches = flushed_matches[tag]
      output = generate_output(count, matches, tag)
      if output
        emit_tag = @tag_proc.call(tag)
        Fluent::Engine.emit(emit_tag, time, output)
      end
    end
  end
end

#generate_output(count, matches, tag = nil) ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 190

def generate_output(count, matches, tag = nil)
  return nil if count.nil?
  return nil if count == 0 # ignore 0 because standby nodes receive no message usually
  return nil if @less_than     and @less_than   <= count
  return nil if @less_equal    and @less_equal  <  count
  return nil if @greater_than  and count <= @greater_than
  return nil if @greater_equal and count <  @greater_equal
  output = {}
  output['count'] = count
  output['message'] = @delimiter.nil? ? matches : matches.join(@delimiter)
  if tag
    output['input_tag'] = tag
    output['input_tag_last'] = tag.split('.').last
  end
  output
end

#load_status(file_path, count_interval) ⇒ Object

Load internal status from a file

Parameters:

  • file_path (String)
  • count_interval (Interger) 


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# File 'lib/fluent/plugin/out_grepcounter.rb', line 257

def load_status(file_path, count_interval)
  return unless (f = Pathname.new(file_path)).exist?
  begin
    f.open('rb') do |f|
      stored = Marshal.load(f)
      if stored[:regexp] == @regexp and
        stored[:exclude] == @exclude and
        stored[:input_key]  == @input_key

        if Fluent::Engine.now <= stored[:saved_at] + count_interval
          @counts = stored[:counts]
          @matches = stored[:matches]
          @saved_at = stored[:saved_at]
          @saved_duration = stored[:saved_duration]

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

#lstrip(string, substring) ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 207

def lstrip(string, substring)
  string.index(substring) == 0 ? string[substring.size..-1] : string
end

#match(string) ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 211

def match(string)
  begin
    return false if @regexp and !@regexp.match(string)
    return false if @exclude and @exclude.match(string)
  rescue ArgumentError => e
    raise e unless e.message.index("invalid byte sequence in") == 0
    string = replace_invalid_byte(string)
    retry
  end
  return true
end

#replace_invalid_byte(string) ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 223

def replace_invalid_byte(string)
  replace_options = { invalid: :replace, undef: :replace, replace: '?' }
  original_encoding = string.encoding
  temporal_encoding = (original_encoding == Encoding::UTF_8 ? Encoding::UTF_16BE : Encoding::UTF_8)
  string.encode(temporal_encoding, original_encoding, replace_options).encode(original_encoding)
end

#save_status(file_path) ⇒ Object

Store internal status into a file

Parameters:

  • file_path (String) 


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# File 'lib/fluent/plugin/out_grepcounter.rb', line 233

def save_status(file_path)
  begin
    Pathname.new(file_path).open('wb') do |f|
      @saved_at = Fluent::Engine.now
      @saved_duration = @saved_at - @last_checked
      Marshal.dump({
        :counts           => @counts,
        :matches          => @matches,
        :saved_at         => @saved_at,
        :saved_duration   => @saved_duration,
        :regexp           => @regexp,
        :exclude          => @exclude,
        :input_key        => @input_key,
      }, f)
    end
  rescue => e
    $log.warn "out_grepcounter: Can't write store_file #{e.class} #{e.message}"
  end
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 116

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_grepcounter.rb', line 110

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

#watcher ⇒ Object

thread callback



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# File 'lib/fluent/plugin/out_grepcounter.rb', line 147

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 >= @count_interval
        now = Fluent::Engine.now
        flush_emit(now - @last_checked)
        @last_checked = now
      end
    rescue => e
      $log.warn "grepcounter: #{e.class} #{e.message} #{e.backtrace.first}"
    end
  end
end