Class: Fluent::ForwardOutput

Inherits:
ObjectBufferedOutput
  • Object
show all
Defined in:
lib/fluent/plugin/out_forward.rb

Defined Under Namespace

Classes: FailureDetector, HeartbeatHandler, HeartbeatRequestTimer, Node, NodeConfig, NoneHeartbeatNode

Constant Summary collapse

LISTEN_PORT = 
24224

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ForwardOutput

Returns a new instance of ForwardOutput.



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# File 'lib/fluent/plugin/out_forward.rb', line 44

def initialize
  super
  require 'fluent/plugin/socket_util'
  @nodes = []  #=> [Node]
  @loop = nil
  @thread = nil
  @finished = false
end

Instance Attribute Details

#nodes ⇒ Object (readonly)

Returns the value of attribute nodes.



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# File 'lib/fluent/plugin/out_forward.rb', line 90

def nodes
  @nodes
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_forward.rb', line 95

def configure(conf)
  super

  recover_sample_size = @recover_wait / @heartbeat_interval

  if @dns_round_robin
    if @heartbeat_type == :udp
      raise ConfigError, "forward output heartbeat type must be 'tcp' or 'none' to use dns_round_robin option"
    end
  end

  conf.elements.each {|e|
    next if e.name != "server"

    host = e['host']
    port = e['port']
    port = port ? port.to_i : LISTEN_PORT

    weight = e['weight']
    weight = weight ? weight.to_i : 60

    standby = !!e['standby']

    name = e['name']
    unless name
      name = "#{host}:#{port}"
    end

    failure = FailureDetector.new(@heartbeat_interval, @hard_timeout, Time.now.to_i.to_f)

    node_conf = NodeConfig.new(name, host, port, weight, standby, failure,
      @phi_threshold, recover_sample_size, @expire_dns_cache, @phi_failure_detector, @dns_round_robin)

    if @heartbeat_type == :none
      @nodes << NoneHeartbeatNode.new(log, node_conf)
    else
      @nodes << Node.new(log, node_conf)
    end
    log.info "adding forwarding server '#{name}'", host: host, port: port, weight: weight, plugin_id: plugin_id
  }

  if @nodes.empty?
    raise ConfigError, "forward output plugin requires at least one <server> is required"
  end
end

#run ⇒ Object 



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# File 'lib/fluent/plugin/out_forward.rb', line 178

def run
  @loop.run if @loop
rescue
  log.error "unexpected error", error: $!.to_s
  log.error_backtrace
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/out_forward.rb', line 166

def shutdown
  @finished = true
  if @loop
    @loop.watchers.each {|w| w.detach }
    @loop.stop
  end
  @thread.join if @thread
  @usock.close if @usock

  super
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/out_forward.rb', line 141

def start
  super

  @rand_seed = Random.new.seed
  rebuild_weight_array
  @rr = 0

  unless @heartbeat_type == :none
    @loop = Coolio::Loop.new

    if @heartbeat_type == :udp
      # assuming all hosts use udp
      @usock = SocketUtil.create_udp_socket(@nodes.first.host)
      @usock.fcntl(Fcntl::F_SETFL, Fcntl::O_NONBLOCK)
      @hb = HeartbeatHandler.new(@usock, method(:on_heartbeat))
      @loop.attach(@hb)
    end

    @timer = HeartbeatRequestTimer.new(@heartbeat_interval, method(:on_timer))
    @loop.attach(@timer)

    @thread = Thread.new(&method(:run))
  end
end

#write_objects(tag, chunk) ⇒ Object 



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# File 'lib/fluent/plugin/out_forward.rb', line 185

def write_objects(tag, chunk)
  return if chunk.empty?

  error = nil

  wlen = @weight_array.length
  wlen.times do
    @rr = (@rr + 1) % wlen
    node = @weight_array[@rr]

    if node.available?
      begin
        send_data(node, tag, chunk)
        return
      rescue
        # for load balancing during detecting crashed servers
        error = $!  # use the latest error
      end
    end
  end

  if error
    raise error
  else
    raise "no nodes are available"  # TODO message
  end
end