Class: LogStash::Pipeline

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

Instance Method Summary collapse

Constructor Details

#initialize(configstr) ⇒ Pipeline

Returns a new instance of Pipeline.



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# File 'lib/logstash/pipeline.rb', line 14

def initialize(configstr)
  @logger = Cabin::Channel.get(LogStash)
  grammar = LogStashConfigParser.new
  @config = grammar.parse(configstr)
  if @config.nil?
    raise LogStash::ConfigurationError, grammar.failure_reason
  end

  # This will compile the config to ruby and evaluate the resulting code.
  # The code will initialize all the plugins and define the
  # filter and output methods.
  code = @config.compile
  # The config code is hard to represent as a log message...
  # So just print it.
  @logger.debug? && @logger.debug("Compiled pipeline code:\n#{code}")
  begin
    eval(code)
  rescue => e
    raise
  end

  @input_to_filter = SizedQueue.new(20)

  # If no filters, pipe inputs directly to outputs
  if !filters?
    @filter_to_output = @input_to_filter
  else
    @filter_to_output = SizedQueue.new(20)
  end
  @settings = {
    "filter-workers" => 1,
  }

  @run_mutex = Mutex.new
  @ready = false
  @started = false
  @input_threads = []
end

Instance Method Details

#configure(setting, value) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 61

def configure(setting, value)
  if setting == "filter-workers"
    # Abort if we have any filters that aren't threadsafe
    if value > 1 && @filters.any? { |f| !f.threadsafe? }
      plugins = @filters.select { |f| !f.threadsafe? }.collect { |f| f.class.config_name }
      raise LogStash::ConfigurationError, "Cannot use more than 1 filter worker because the following plugins don't work with more than one worker: #{plugins.join(", ")}"
    end
  end
  @settings[setting] = value
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 296

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

#filters? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 72

def filters?
  return @filters.any?
end

#filterworker ⇒ Object

def inputworker



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# File 'lib/logstash/pipeline.rb', line 209

def filterworker
  LogStash::Util::set_thread_name("|worker")
  begin
    while true
      event = @input_to_filter.pop

      case event
      when LogStash::Event
        # filter_func returns all filtered events, including cancelled ones
        filter_func(event).each { |e| @filter_to_output.push(e) unless e.cancelled? }
      when LogStash::FlushEvent
        # handle filter flushing here so that non threadsafe filters (thus only running one filterworker)
        # don't have to deal with thread safety implementing the flush method
        flush_filters_to_output!
      when LogStash::ShutdownEvent
        # pass it down to any other filterworker and stop this worker
        @input_to_filter.push(event)
        break
      end
    end
  rescue => e
    @logger.error("Exception in filterworker", "exception" => e, "backtrace" => e.backtrace)
  end

  @filters.each(&:teardown)
end

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

perform filters flush and yeild 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 304

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_output!(options = {}) ⇒ Object

perform filters flush into the output queue

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 315

def flush_filters_to_output!(options = {})
  flush_filters(options) do |event|
    unless event.cancelled?
      @logger.debug? and @logger.debug("Pushing flushed events", :event => event)
      @filter_to_output.push(event)
    end
  end
end

#inputworker(plugin) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 173

def inputworker(plugin)
  LogStash::Util::set_thread_name("<#{plugin.class.config_name}")
  begin
    plugin.run(@input_to_filter)
  rescue LogStash::ShutdownSignal
    # ignore and quit
  rescue => e
    if @logger.debug?
      @logger.error(I18n.t("logstash.pipeline.worker-error-debug",
                           :plugin => plugin.inspect, :error => e.to_s,
                           :exception => e.class,
                           :stacktrace => e.backtrace.join("\n")))
    else
      @logger.error(I18n.t("logstash.pipeline.worker-error",
                           :plugin => plugin.inspect, :error => e))
    end
    puts e.backtrace if @logger.debug?
    # input teardown must be synchronized since is can be called concurrently by
    # the input worker thread and from the pipeline thread shutdown method.
    # this means that input teardown methods must support multiple calls.
    @run_mutex.synchronize{plugin.teardown}
    sleep 1
    retry
  end
ensure
  begin
    # input teardown must be synchronized since is can be called concurrently by
    # the input worker thread and from the pipeline thread shutdown method.
    # this means that input teardown methods must support multiple calls.
    @run_mutex.synchronize{plugin.teardown}
  rescue LogStash::ShutdownSignal
    # teardown could receive the ShutdownSignal, retry it
    retry
  end
end

#outputworker ⇒ Object

def filterworker



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# File 'lib/logstash/pipeline.rb', line 236

def outputworker
  LogStash::Util::set_thread_name(">output")
  @outputs.each(&:worker_setup)

  while true
    event = @filter_to_output.pop
    break if event == LogStash::SHUTDOWN
    output_func(event)
  end # while true

  @outputs.each do |output|
    output.worker_plugins.each(&:teardown)
  end
end

#plugin(plugin_type, name, *args) ⇒ Object

def shutdown



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# File 'lib/logstash/pipeline.rb', line 288

def plugin(plugin_type, name, *args)
  args << {} if args.empty?
  klass = LogStash::Plugin.lookup(plugin_type, name)
  return klass.new(*args)
end

#ready? ⇒ Boolean

def initialize

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 53

def ready?
  @run_mutex.synchronize{@ready}
end

#run ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 76

def run
  @run_mutex.synchronize{@started = true}

  # synchronize @input_threads between run and shutdown
  @run_mutex.synchronize{start_inputs}
  start_filters if filters?
  start_outputs

  @run_mutex.synchronize{@ready = true}

  @logger.info("Pipeline started")
  @logger.terminal("Logstash startup completed")

  wait_inputs

  if filters?
    shutdown_filters
    wait_filters
    flush_filters_to_output!(:final => true)
  end

  shutdown_outputs
  wait_outputs

  @logger.info("Pipeline shutdown complete.")
  @logger.terminal("Logstash shutdown completed")

  # exit code
  return 0
end

#shutdown ⇒ Object

Shutdown this pipeline.

This method is intended to be called from another thread



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# File 'lib/logstash/pipeline.rb', line 254

def shutdown
  @input_threads.each do |thread|
    # Interrupt all inputs
    @logger.info("Sending shutdown signal to input thread", :thread => thread)

    # synchronize both ShutdownSignal and teardown below. by synchronizing both
    # we will avoid potentially sending a shutdown signal when the inputworker is
    # executing the teardown method.
    @run_mutex.synchronize do
      thread.raise(LogStash::ShutdownSignal)
      begin
        thread.wakeup # in case it's in blocked IO or sleeping
      rescue ThreadError
      end
    end
  end

  # sometimes an input is stuck in a blocking I/O so we need to tell it to teardown directly
  @inputs.each do |input|
    begin
      # input teardown must be synchronized since is can be called concurrently by
      # the input worker thread and from the pipeline thread shutdown method.
      # this means that input teardown methods must support multiple calls.
      @run_mutex.synchronize{input.teardown}
    rescue LogStash::ShutdownSignal
      # teardown could receive the ShutdownSignal, retry it
      retry
    end
  end

  # No need to send the ShutdownEvent to the filters/outputs nor to wait for
  # the inputs to finish, because in the #run method we wait for that anyway.
end

#shutdown_filters ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 117

def shutdown_filters
  @flusher_thread.kill
  @input_to_filter.push(LogStash::SHUTDOWN)
end

#shutdown_outputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 126

def shutdown_outputs
  # nothing, filters will do this
  @filter_to_output.push(LogStash::SHUTDOWN)
end

#start_filters ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 153

def start_filters
  @filters.each(&:register)
  @filter_threads = @settings["filter-workers"].times.collect do
    Thread.new { filterworker }
  end

  @flusher_thread = Thread.new { Stud.interval(5) { @input_to_filter.push(LogStash::FLUSH) } }
end

#start_input(plugin) ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 169

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

#start_inputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 136

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

  @inputs.each do |input|
    input.register
    start_input(input)
  end
end

#start_outputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 162

def start_outputs
  @outputs.each(&:register)
  @output_threads = [
    Thread.new { outputworker }
  ]
end

#started? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/logstash/pipeline.rb', line 57

def started?
  @run_mutex.synchronize{@started}
end

#wait_filters ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 122

def wait_filters
  @filter_threads.each(&:join) if @filter_threads
end

#wait_inputs ⇒ Object

def run



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# File 'lib/logstash/pipeline.rb', line 107

def wait_inputs
  @input_threads.each(&:join)
rescue Interrupt
  # rbx does weird things during do SIGINT that I haven't debugged
  # so we catch Interrupt here and signal a shutdown. For some reason the
  # signal handler isn't invoked it seems? I dunno, haven't looked much into
  # it.
  shutdown
end

#wait_outputs ⇒ Object 



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# File 'lib/logstash/pipeline.rb', line 131

def wait_outputs
  # Wait for the outputs to stop
  @output_threads.each(&:join)
end