Class: LogStash::Pipeline

Inherits:
BasePipeline show all
Defined in:
lib/logstash/pipeline.rb

Constant Summary collapse

MAX_INFLIGHT_WARN_THRESHOLD = 
10_000

Instance Attribute Summary collapse

Attributes inherited from BasePipeline

#config_hash, #config_str, #filters, #inputs, #outputs, #pipeline_id

Instance Method Summary collapse

Methods inherited from BasePipeline

#non_reloadable_plugins, #plugin, #reloadable?

Methods included from Util::Loggable

included, #logger, #slow_logger

Constructor Details

#initialize(config_str, settings = SETTINGS, namespaced_metric = nil) ⇒ Pipeline

Returns a new instance of Pipeline.



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# File 'lib/logstash/pipeline.rb', line 152

def initialize(config_str, settings = SETTINGS, namespaced_metric = nil)
  # This needs to be configured before we call super which will evaluate the code to make
  # sure the metric instance is correctly send to the plugins to make the namespace scoping work
  @metric = if namespaced_metric
    settings.get("metric.collect") ? namespaced_metric : Instrument::NullMetric.new(namespaced_metric.collector)
  else
    Instrument::NullMetric.new
  end

  @settings = settings
  @reporter = PipelineReporter.new(@logger, self)
  @worker_threads = []

  super(config_str, settings)

  begin
    @queue = LogStash::QueueFactory.create(settings)
  rescue => e
    @logger.error("Logstash failed to create queue", "exception" => e.message, "backtrace" => e.backtrace)
    raise e
  end

  @input_queue_client = @queue.write_client
  @filter_queue_client = @queue.read_client
  @signal_queue = Queue.new
  # Note that @inflight_batches as a central mechanism for tracking inflight
  # batches will fail if we have multiple read clients here.
  @filter_queue_client.set_events_metric(metric.namespace([:stats, :events]))
  @filter_queue_client.set_pipeline_metric(
      metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :events])
  )
  @drain_queue =  @settings.get_value("queue.drain")


  @events_filtered = Concurrent::AtomicFixnum.new(0)
  @events_consumed = Concurrent::AtomicFixnum.new(0)

  @input_threads = []
  # @ready requires thread safety since it is typically polled from outside the pipeline thread
  @ready = Concurrent::AtomicBoolean.new(false)
  @running = Concurrent::AtomicBoolean.new(false)
  @flushing = Concurrent::AtomicReference.new(false)
end

Instance Attribute Details

#events_consumed ⇒ Object (readonly)

Returns the value of attribute events_consumed.



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# File 'lib/logstash/pipeline.rb', line 137

def events_consumed
  @events_consumed
end

#events_filtered ⇒ Object (readonly)

Returns the value of attribute events_filtered.



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# File 'lib/logstash/pipeline.rb', line 137

def events_filtered
  @events_filtered
end

#filter_queue_client ⇒ Object (readonly)

Returns the value of attribute filter_queue_client.



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# File 'lib/logstash/pipeline.rb', line 137

def filter_queue_client
  @filter_queue_client
end

#input_queue_client ⇒ Object (readonly)

Returns the value of attribute input_queue_client.



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# File 'lib/logstash/pipeline.rb', line 137

def input_queue_client
  @input_queue_client
end

#metric ⇒ Object (readonly)

Returns the value of attribute metric.



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# File 'lib/logstash/pipeline.rb', line 137

def metric
  @metric
end

#queue ⇒ Object (readonly)

Returns the value of attribute queue.



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# File 'lib/logstash/pipeline.rb', line 137

def queue
  @queue
end

#reporter ⇒ Object (readonly)

Returns the value of attribute reporter.



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# File 'lib/logstash/pipeline.rb', line 137

def reporter
  @reporter
end

#settings ⇒ Object (readonly)

Returns the value of attribute settings.



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# File 'lib/logstash/pipeline.rb', line 137

def settings
  @settings
end

#started_at ⇒ Object (readonly)

Returns the value of attribute started_at.



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# File 'lib/logstash/pipeline.rb', line 137

def started_at
  @started_at
end

#thread ⇒ Object (readonly)

Returns the value of attribute thread.



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# File 'lib/logstash/pipeline.rb', line 137

def thread
  @thread
end

#worker_threads ⇒ Object (readonly)

Returns the value of attribute worker_threads.



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# File 'lib/logstash/pipeline.rb', line 137

def worker_threads
  @worker_threads
end

Instance Method Details

#close ⇒ Object

def run



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# File 'lib/logstash/pipeline.rb', line 260

def close
  @filter_queue_client.close
  @queue.close
  @dlq_writer.close
end

#collect_dlq_stats ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 616

def collect_dlq_stats
  if dlq_enabled?
    dlq_metric = @metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :dlq])
    dlq_metric.gauge(:queue_size_in_bytes, @dlq_writer.get_current_queue_size)
  end
end

#collect_stats ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 623

def collect_stats
  pipeline_metric = @metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :queue])
  pipeline_metric.gauge(:type, settings.get("queue.type"))

  if @queue.is_a?(LogStash::Util::WrappedAckedQueue) && @queue.queue.is_a?(LogStash::AckedQueue)
    queue = @queue.queue
    dir_path = queue.dir_path
    file_store = Files.get_file_store(Paths.get(dir_path))

    pipeline_metric.namespace([:capacity]).tap do |n|
      n.gauge(:page_capacity_in_bytes, queue.page_capacity)
      n.gauge(:max_queue_size_in_bytes, queue.max_size_in_bytes)
      n.gauge(:max_unread_events, queue.max_unread_events)
      n.gauge(:queue_size_in_bytes, queue.persisted_size_in_bytes)
    end
    pipeline_metric.namespace([:data]).tap do |n|
      n.gauge(:free_space_in_bytes, file_store.get_unallocated_space)
      n.gauge(:storage_type, file_store.type)
      n.gauge(:path, dir_path)
    end

    pipeline_metric.gauge(:events, queue.unread_count)
  end
end

#dlq_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 362

def dlq_enabled?
  @settings.get("dead_letter_queue.enable")
end

#filter(event, &block) ⇒ Object

for backward compatibility in devutils for the rspec helpers, this method is not used in the pipeline anymore.



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# File 'lib/logstash/pipeline.rb', line 538

def filter(event, &block)
  # filter_func returns all filtered events, including cancelled ones
  filter_func([event]).each {|e| block.call(e)}
end

#filter_batch(batch) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 397

def filter_batch(batch)
  filter_func(batch.to_a).each do |e|
    #these are both original and generated events
    batch.merge(e) unless e.cancelled?
  end
  @filter_queue_client.add_filtered_metrics(batch)
  @events_filtered.increment(batch.size)
rescue Exception => e
  # Plugins authors should manage their own exceptions in the plugin code
  # but if an exception is raised up to the worker thread they are considered
  # fatal and logstash will not recover from this situation.
  #
  # Users need to check their configuration or see if there is a bug in the
  # plugin.
  @logger.error("Exception in pipelineworker, the pipeline stopped processing new events, please check your filter configuration and restart Logstash.",
                "exception" => e.message, "backtrace" => e.backtrace)

  raise e
end

#filters? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 225

def filters?
  return @filters.any?
end

#flush ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 571

def flush
  if @flushing.compare_and_set(false, true)
    @logger.debug? && @logger.debug("Pushing flush onto pipeline")
    @signal_queue.push(FLUSH)
  end
end

#flush_filters(options = {}, &block) ⇒ Object

perform filters flush and yield flushed event to the passed block

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :final (Boolean) —

    > true to signal a final shutdown flush



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# File 'lib/logstash/pipeline.rb', line 547

def flush_filters(options = {}, &block)
  flushers = options[:final] ? @shutdown_flushers : @periodic_flushers

  flushers.each do |flusher|
    flusher.call(options, &block)
  end
end

#flush_filters_to_batch(batch, options = {}) ⇒ Object

perform filters flush into the output queue

Parameters:

  • batch (ReadClient::ReadBatch)
  • options (Hash) (defaults to: {}) 


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# File 'lib/logstash/pipeline.rb', line 591

def flush_filters_to_batch(batch, options = {})
  flush_filters(options) do |event|
    unless event.cancelled?
      @logger.debug? and @logger.debug("Pushing flushed events", :event => event)
      batch.merge(event)
    end
  end

  @flushing.set(false)
end

#inputworker(plugin) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 466

def inputworker(plugin)
  Util::set_thread_name("[#{pipeline_id}]<#{plugin.class.config_name}")
  begin
    input_queue_client = wrapped_write_client(plugin)
    plugin.run(input_queue_client)
  rescue => e
    if plugin.stop?
      @logger.debug("Input plugin raised exception during shutdown, ignoring it.",
                    :plugin => plugin.class.config_name, :exception => e.message,
                    :backtrace => e.backtrace)
      return
    end

    # otherwise, report error and restart
    if @logger.debug?
      @logger.error(I18n.t("logstash.pipeline.worker-error-debug",
                           :plugin => plugin.inspect, :error => e.message,
                           :exception => e.class,
                           :stacktrace => e.backtrace.join("\n")))
    else
      @logger.error(I18n.t("logstash.pipeline.worker-error",
                           :plugin => plugin.inspect, :error => e.message))
    end

    # Assuming the failure that caused this exception is transient,
    # let's sleep for a bit and execute #run again
    sleep(1)
    retry
  ensure
    plugin.do_close
  end
end

#inspect ⇒ Object

Sometimes we log stuff that will dump the pipeline which may contain sensitive information (like the raw syntax tree which can contain passwords) We want to hide most of what’s in here



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# File 'lib/logstash/pipeline.rb', line 651

def inspect
  {
    :pipeline_id => @pipeline_id,
    :settings => @settings.inspect,
    :ready => @ready,
    :running => @running,
    :flushing => @flushing
  }
end

#output_batch(batch) ⇒ Object

Take an array of events and send them to the correct output



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# File 'lib/logstash/pipeline.rb', line 418

def output_batch(batch)
  # Build a mapping of { output_plugin => [events...]}
  output_events_map = Hash.new { |h, k| h[k] = [] }
  batch.each do |event|
    # We ask the AST to tell us which outputs to send each event to
    # Then, we stick it in the correct bin

    # output_func should never return anything other than an Array but we have lots of legacy specs
    # that monkeypatch it and return nil. We can deprecate  "|| []" after fixing these specs
    (output_func(event) || []).each do |output|
      output_events_map[output].push(event)
    end
  end
  # Now that we have our output to event mapping we can just invoke each output
  # once with its list of events
  output_events_map.each do |output, events|
    output.multi_receive(events)
  end

  @filter_queue_client.add_output_metrics(batch)
end

#plugin_threads_info ⇒ Object

flush_filters_to_batch



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# File 'lib/logstash/pipeline.rb', line 602

def plugin_threads_info
  input_threads = @input_threads.select {|t| t.alive? }
  worker_threads = @worker_threads.select {|t| t.alive? }
  (input_threads + worker_threads).map {|t| Util.thread_info(t) }
end

#ready? ⇒ Boolean

def initialize

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 196

def ready?
  @ready.value
end

#register_plugin(plugin) ⇒ Plugin

register_plugin simply calls the plugin #register method and catches & logs any error

Parameters:

  • plugin (Plugin) —

    the plugin to register

Returns:

  • (Plugin) —

    the registered plugin



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# File 'lib/logstash/pipeline.rb', line 289

def register_plugin(plugin)
  plugin.register
  plugin
rescue => e
  @logger.error("Error registering plugin", :plugin => plugin.inspect, :error => e.message)
  raise e
end

#register_plugins(plugins) ⇒ Object

register_plugins calls #register_plugin on the plugins list and upon exception will call Plugin#do_close on all registered plugins

Parameters:

  • plugins (Array[Plugin]) —

    the list of plugins to register



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# File 'lib/logstash/pipeline.rb', line 299

def register_plugins(plugins)
  registered = []
  plugins.each { |plugin| registered << register_plugin(plugin) }
rescue => e
  registered.each(&:do_close)
  raise e
end

#run ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 229

def run
  @started_at = Time.now

  @thread = Thread.current
  Util.set_thread_name("[#{pipeline_id}]-pipeline-manager")

  start_workers

  @logger.info("Pipeline #{@pipeline_id} started")

  # Block until all inputs have stopped
  # Generally this happens if SIGINT is sent and `shutdown` is called from an external thread

  transition_to_running
  start_flusher # Launches a non-blocking thread for flush events
  wait_inputs
  transition_to_stopped

  @logger.debug("Input plugins stopped! Will shutdown filter/output workers.")

  shutdown_flusher
  shutdown_workers

  close

  @logger.debug("Pipeline #{@pipeline_id} has been shutdown")

  # exit code
  return 0
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 274

def running?
  @running.true?
end

#safe_pipeline_worker_count ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 200

def safe_pipeline_worker_count
  default = @settings.get_default("pipeline.workers")
  pipeline_workers = @settings.get("pipeline.workers") #override from args "-w 8" or config
  safe_filters, unsafe_filters = @filters.partition(&:threadsafe?)
  plugins = unsafe_filters.collect { |f| f.config_name }

  return pipeline_workers if unsafe_filters.empty?

  if @settings.set?("pipeline.workers")
    if pipeline_workers > 1
      @logger.warn("Warning: Manual override - there are filters that might not work with multiple worker threads",
                   :worker_threads => pipeline_workers, :filters => plugins)
    end
  else
    # user did not specify a worker thread count
    # warn if the default is multiple
    if default > 1
      @logger.warn("Defaulting pipeline worker threads to 1 because there are some filters that might not work with multiple worker threads",
                   :count_was => default, :filters => plugins)
      return 1 # can't allow the default value to propagate if there are unsafe filters
    end
  end
  pipeline_workers
end

#shutdown(&before_stop) ⇒ Object

initiate the pipeline shutdown sequence this method is intended to be called from outside the pipeline thread

Parameters:

  • before_stop (Proc) —

    code block called before performing stop operation on input plugins



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# File 'lib/logstash/pipeline.rb', line 502

def shutdown(&before_stop)
  # shutdown can only start once the pipeline has completed its startup.
  # avoid potential race condition between the startup sequence and this
  # shutdown method which can be called from another thread at any time
  sleep(0.1) while !ready?

  # TODO: should we also check against calling shutdown multiple times concurrently?

  before_stop.call if block_given?

  @logger.debug "Closing inputs"
  @inputs.each(&:do_stop)
  @logger.debug "Closed inputs"
end

#shutdown_flusher ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 567

def shutdown_flusher
  @flusher_thread.join
end

#shutdown_workers ⇒ Object

After ‘shutdown` is called from an external thread this is called from the main thread to tell the worker threads to stop and then block until they’ve fully stopped This also stops all filter and output plugins



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# File 'lib/logstash/pipeline.rb', line 520

def shutdown_workers
  # Each worker thread will receive this exactly once!
  @worker_threads.each do |t|
    @logger.debug("Pushing shutdown", :thread => t.inspect)
    @signal_queue.push(SHUTDOWN)
  end

  @worker_threads.each do |t|
    @logger.debug("Shutdown waiting for worker thread #{t}")
    t.join
  end

  @filters.each(&:do_close)
  @outputs.each(&:do_close)
end

#stalling_threads_info ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 608

def stalling_threads_info
  plugin_threads_info
    .reject {|t| t["blocked_on"] } # known benign blocking statuses
    .each {|t| t.delete("backtrace") }
    .each {|t| t.delete("blocked_on") }
    .each {|t| t.delete("status") }
end

#start_flusher ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 555

def start_flusher
  # Invariant to help detect improper initialization
  raise "Attempted to start flusher on a stopped pipeline!" if stopped?

  @flusher_thread = Thread.new do
    while Stud.stoppable_sleep(5, 0.1) { stopped? }
      flush
      break if stopped?
    end
  end
end

#start_input(plugin) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 462

def start_input(plugin)
  @input_threads << Thread.new { inputworker(plugin) }
end

#start_inputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 444

def start_inputs
  moreinputs = []
  @inputs.each do |input|
    if input.threadable && input.threads > 1
      (input.threads - 1).times do |i|
        moreinputs << input.clone
      end
    end
  end
  @inputs += moreinputs

  # first make sure we can register all input plugins
  register_plugins(@inputs)

  # then after all input plugins are successfully registered, start them
  @inputs.each { |input| start_input(input) }
end

#start_workers ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 307

def start_workers
  @worker_threads.clear # In case we're restarting the pipeline
  begin
    register_plugins(@outputs)
    register_plugins(@filters)

    pipeline_workers = safe_pipeline_worker_count
    batch_size = @settings.get("pipeline.batch.size")
    batch_delay = @settings.get("pipeline.batch.delay")

    max_inflight = batch_size * pipeline_workers

    config_metric = metric.namespace([:stats, :pipelines, pipeline_id.to_s.to_sym, :config])
    config_metric.gauge(:workers, pipeline_workers)
    config_metric.gauge(:batch_size, batch_size)
    config_metric.gauge(:batch_delay, batch_delay)
    config_metric.gauge(:config_reload_automatic, @settings.get("config.reload.automatic"))
    config_metric.gauge(:config_reload_interval, @settings.get("config.reload.interval"))
    config_metric.gauge(:dead_letter_queue_enabled, dlq_enabled?)
    config_metric.gauge(:dead_letter_queue_path, @dlq_writer.get_path.to_absolute_path.to_s) if dlq_enabled?


    @logger.info("Starting pipeline",
                 "id" => self.pipeline_id,
                 "pipeline.workers" => pipeline_workers,
                 "pipeline.batch.size" => batch_size,
                 "pipeline.batch.delay" => batch_delay,
                 "pipeline.max_inflight" => max_inflight)
    if max_inflight > MAX_INFLIGHT_WARN_THRESHOLD
      @logger.warn "CAUTION: Recommended inflight events max exceeded! Logstash will run with up to #{max_inflight} events in memory in your current configuration. If your message sizes are large this may cause instability with the default heap size. Please consider setting a non-standard heap size, changing the batch size (currently #{batch_size}), or changing the number of pipeline workers (currently #{pipeline_workers})"
    end

    pipeline_workers.times do |t|
      @worker_threads << Thread.new do
        Util.set_thread_name("[#{pipeline_id}]>worker#{t}")
        worker_loop(batch_size, batch_delay)
      end
    end

    # inputs should be started last, after all workers
    begin
      start_inputs
    rescue => e
      # if there is any exception in starting inputs, make sure we shutdown workers.
      # exception will already by logged in start_inputs
      shutdown_workers
      raise e
    end
  ensure
    # it is important to guarantee @ready to be true after the startup sequence has been completed
    # to potentially unblock the shutdown method which may be waiting on @ready to proceed
    @ready.make_true
  end
end

#stopped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 278

def stopped?
  @running.false?
end

#system? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 282

def system?
  settings.get_value("pipeline.system")
end

#transition_to_running ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 266

def transition_to_running
  @running.make_true
end

#transition_to_stopped ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 270

def transition_to_stopped
  @running.make_false
end

#uptime ⇒ Fixnum

Calculate the uptime in milliseconds

Returns:

  • (Fixnum) —

    Uptime in milliseconds, 0 if the pipeline is not started



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# File 'lib/logstash/pipeline.rb', line 582

def uptime
  return 0 if started_at.nil?
  ((Time.now.to_f - started_at.to_f) * 1000.0).to_i
end

#wait_inputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 440

def wait_inputs
  @input_threads.each(&:join)
end

#worker_loop(batch_size, batch_delay) ⇒ Object

Main body of what a worker thread does Repeatedly takes batches off the queue, filters, then outputs them



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# File 'lib/logstash/pipeline.rb', line 368

def worker_loop(batch_size, batch_delay)
  shutdown_requested = false

  @filter_queue_client.set_batch_dimensions(batch_size, batch_delay)

  while true
    signal = @signal_queue.empty? ? NO_SIGNAL : @signal_queue.pop
    shutdown_requested |= signal.shutdown? # latch on shutdown signal

    batch = @filter_queue_client.read_batch # metrics are started in read_batch
    @events_consumed.increment(batch.size)
    filter_batch(batch)
    flush_filters_to_batch(batch, :final => false) if signal.flush?
    output_batch(batch)
    @filter_queue_client.close_batch(batch)

    # keep break at end of loop, after the read_batch operation, some pipeline specs rely on this "final read_batch" before shutdown.
    break if shutdown_requested && !draining_queue?
  end

  # we are shutting down, queue is drained if it was required, now  perform a final flush.
  # for this we need to create a new empty batch to contain the final flushed events
  batch = @filter_queue_client.new_batch
  @filter_queue_client.start_metrics(batch) # explicitly call start_metrics since we dont do a read_batch here
  flush_filters_to_batch(batch, :final => true)
  output_batch(batch)
  @filter_queue_client.close_batch(batch)
end