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

#filters, #inputs, #outputs

Instance Method Summary collapse

Methods inherited from BasePipeline

#non_reloadable_plugins, #reloadable?, #reloadable_plugins?

Constructor Details

#initialize(pipeline_config, namespaced_metric = nil, agent = nil) ⇒ Pipeline

Returns a new instance of Pipeline.



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# File 'lib/logstash/pipeline.rb', line 89

def initialize(pipeline_config, namespaced_metric = nil, agent = nil)
  super
  open_queue

  @worker_threads = []

  @signal_queue = java.util.concurrent.LinkedBlockingQueue.new

  @drain_queue =  settings.get_value("queue.drain") || settings.get("queue.type") == "memory"


  @events_filtered = java.util.concurrent.atomic.LongAdder.new
  @events_consumed = java.util.concurrent.atomic.LongAdder.new

  @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)
  @outputs_registered = Concurrent::AtomicBoolean.new(false)
  @worker_shutdown = java.util.concurrent.atomic.AtomicBoolean.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 80

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 80

def events_filtered
  @events_filtered
end

#started_at ⇒ Object (readonly)

Returns the value of attribute started_at.



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# File 'lib/logstash/pipeline.rb', line 80

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 80

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 80

def worker_threads
  @worker_threads
end

Instance Method Details

#clear_pipeline_metrics ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 563

def clear_pipeline_metrics
  # TODO(ph): I think the metric should also proxy that call correctly to the collector
  # this will simplify everything since the null metric would simply just do a noop
  collector = metric.collector

  unless collector.nil?
    # selectively reset metrics we don't wish to keep after reloading
    # these include metrics about the plugins and number of processed events
    # we want to keep other metrics like reload counts and error messages
    collector.clear("stats/pipelines/#{pipeline_id}/plugins")
    collector.clear("stats/pipelines/#{pipeline_id}/events")
  end
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 486

def filter(event, &block)
  maybe_setup_out_plugins
  # 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 340

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.filtered_size)
  @events_filtered.add(batch.filteredSize)
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.",
                default_logging_keys("exception" => e.message, "backtrace" => e.backtrace))

  raise e
end

#filters? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 140

def filters?
  return @filters.any?
end

#flush ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 519

def flush
  if @flushing.compare_and_set(false, true)
    @logger.debug? && @logger.debug("Pushing flush onto pipeline", default_logging_keys)
    @signal_queue.put(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 495

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 538

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

  @flushing.set(false)
end

#inputworker(plugin) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 406

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

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

    # 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 580

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

#output_batch(batch, output_events_map) ⇒ Object

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



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# File 'lib/logstash/pipeline.rb', line 361

def output_batch(batch, output_events_map)
  # Build a mapping of { output_plugin => [events...]}
  batch.to_a.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(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)
    events.clear
  end

  filter_queue_client.add_output_metrics(batch.filtered_size)
end

#plugin_threads_info ⇒ Object

flush_filters_to_batch



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# File 'lib/logstash/pipeline.rb', line 549

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 112

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 241

def register_plugin(plugin)
  plugin.register
  plugin
rescue => e
  @logger.error("Error registering plugin", default_logging_keys(: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 251

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 195

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

  start_workers

  # 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

  shutdown_flusher
  @logger.debug("Shutting down filter/output workers", default_logging_keys)
  shutdown_workers

  close

  @logger.info("Pipeline has terminated", default_logging_keys)

  # exit code
  return 0
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 230

def running?
  @running.true?
end

#safe_pipeline_worker_count ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 116

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", default_logging_keys(: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",
                   default_logging_keys(: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 437

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?

  stop_inputs

  # We make this call blocking, so we know for sure when the method return the shtudown is
  # stopped
  wait_for_workers
  clear_pipeline_metrics
end

#shutdown_flusher ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 515

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 471

def shutdown_workers
  @logger.debug("Setting shutdown", default_logging_keys)
  @worker_shutdown.set(true)

  @worker_threads.each do |t|
    @logger.debug("Shutdown waiting for worker thread" , default_logging_keys(:thread => t.inspect))
    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 555

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 ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 144

def start
  # Since we start lets assume that the metric namespace is cleared
  # this is useful in the context of pipeline reloading
  collect_stats
  collect_dlq_stats

  @logger.info("Starting pipeline", default_logging_keys(
    "pipeline.workers" => settings.get("pipeline.workers"),
    "pipeline.batch.size" => settings.get("pipeline.batch.size"),
    "pipeline.batch.delay" => settings.get("pipeline.batch.delay")))

  @finished_execution = Concurrent::AtomicBoolean.new(false)

  @thread = Thread.new do
    begin
      LogStash::Util.set_thread_name("pipeline.#{pipeline_id}")
      run
      @finished_execution.make_true
    rescue => e
      close
      @logger.error("Pipeline aborted due to error", default_logging_keys(:exception => e, :backtrace => e.backtrace))
    end
  end

  status = wait_until_started

  if status
    @logger.info("Pipeline started successfully", default_logging_keys)
  end

  status
end

#start_flusher ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 503

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 402

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

#start_inputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 384

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 259

def start_workers
  @worker_threads.clear # In case we're restarting the pipeline
  @outputs_registered.make_false
  begin
    maybe_setup_out_plugins

    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?

    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})", default_logging_keys)
    end

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

#stop_inputs ⇒ Object 



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

def stop_inputs
  @logger.debug("Stopping inputs", default_logging_keys)
  @inputs.each(&:do_stop)
  @logger.debug("Stopped inputs", default_logging_keys)
end

#stopped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 234

def stopped?
  @running.false?
end

#transition_to_running ⇒ Object

def run



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# File 'lib/logstash/pipeline.rb', line 222

def transition_to_running
  @running.make_true
end

#transition_to_stopped ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 226

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 529

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

#wait_for_workers ⇒ Object

def shutdown



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# File 'lib/logstash/pipeline.rb', line 455

def wait_for_workers
  @worker_threads.each do |t|
    t.join
    @logger.debug("Worker terminated", default_logging_keys(:thread => t.inspect))
  end
end

#wait_inputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 380

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

#wait_until_started ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 177

def wait_until_started
  while true do
    # This should be changed with an appropriate FSM
    # It's an edge case, if we have a pipeline with
    # a generator { count => 1 } its possible that `Thread#alive?` doesn't return true
    # because the execution of the thread was successful and complete
    if @finished_execution.true?
      return true
    elsif !thread.alive?
      return false
    elsif running?
      return true
    else
      sleep 0.01
    end
  end
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 310

def worker_loop(batch_size, batch_delay)
  filter_queue_client.set_batch_dimensions(batch_size, batch_delay)
  output_events_map = Hash.new { |h, k| h[k] = [] }
  while true
    signal = @signal_queue.poll || NO_SIGNAL

    batch = filter_queue_client.read_batch.to_java # metrics are started in read_batch
    batch_size = batch.filteredSize
    if batch_size > 0
      @events_consumed.add(batch_size)
      filter_batch(batch)
    end
    flush_filters_to_batch(batch, :final => false) if signal.flush?
    if batch.filteredSize > 0
      output_batch(batch, output_events_map)
      filter_queue_client.close_batch(batch)
    end
    # keep break at end of loop, after the read_batch operation, some pipeline specs rely on this "final read_batch" before shutdown.
    break if (@worker_shutdown.get && !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.to_java.newBatch
  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, output_events_map)
  filter_queue_client.close_batch(batch)
end