Class: Bricolage::StreamingLoad::Dispatcher

Inherits:
Bricolage::SQSDataSource::MessageHandler show all
Defined in:
lib/bricolage/streamingload/dispatcher.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Bricolage::SQSDataSource::MessageHandler

#call_handler_method, #handle, #handleable?, #handler_method

Constructor Details

#initialize(event_queue:, task_queue:, chunk_router:, chunk_buffer:, task_logger:, dispatch_interval:, logger:) ⇒ Dispatcher

Returns a new instance of Dispatcher.



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 98

def initialize(event_queue:, task_queue:, chunk_router:, chunk_buffer:, task_logger:, dispatch_interval:, logger:)
  @event_queue = event_queue
  @task_queue = task_queue
  @chunk_router = chunk_router
  @chunk_buffer = chunk_buffer
  @task_logger = task_logger
  @dispatch_interval = dispatch_interval
  @dispatch_message_id = nil
  @logger = logger
  @dispatch_requested = false
  @checkpoint_requested = false
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 111

def logger
  @logger
end

Class Method Details

.create_pid_file(path) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 90

def Dispatcher.create_pid_file(path)
  File.open(path, 'w') {|f|
    f.puts $$
  }
rescue
  # ignore
end

.main ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 22

def Dispatcher.main
  opts = DispatcherOptions.new(ARGV)
  opts.parse
  unless opts.rest_arguments.size == 1
    $stderr.puts opts.usage
    exit 1
  end
  config_path, * = opts.rest_arguments
  config = YAML.load(File.read(config_path))
  log = opts.log_file_path ? new_logger(File.expand_path(opts.log_file_path), config) : nil
  ctx = Context.for_application('.', environment: opts.environment, logger: log)
  logger = raw_logger = ctx.logger
  event_queue = ctx.get_data_source('sqs', config.fetch('event-queue-ds', 'sqs_event'))
  task_queue = ctx.get_data_source('sqs', config.fetch('task-queue-ds', 'sqs_task'))
  if config['alert-level']
    logger = AlertingLogger.new(
      logger: raw_logger,
      sns_datasource: ctx.get_data_source('sns', config.fetch('sns-ds', 'sns')),
      alert_level: config.fetch('alert-level', 'warn')
    )
  end

  chunk_buffer = ChunkBuffer.new(
    control_data_source: ctx.get_data_source('sql', config.fetch('ctl-postgres-ds', 'db_ctl')),
    logger: logger
  )

  chunk_router = ChunkRouter.for_config(config.fetch('url_patterns'))

  task_logger = LoadTaskLogger.new(
    ctx.get_data_source('s3', config.fetch('ctl-s3-ds', 's3_ctl'))
  )

  dispatcher = Dispatcher.new(
    event_queue: event_queue,
    task_queue: task_queue,
    chunk_router: chunk_router,
    chunk_buffer: chunk_buffer,
    task_logger: task_logger,
    dispatch_interval: config.fetch('dispatch-interval', 60),
    logger: logger
  )

  if opts.task_id
    dispatcher.dispatch_tasks chunk_buffer.load_tasks_by_id([opts.task_id])
    exit 0
  end

  Process.daemon(true) if opts.daemon?
  create_pid_file opts.pid_file_path if opts.pid_file_path
  Dir.chdir '/'
  begin
    dispatcher.event_loop
  rescue Exception => e
    logger.exception e
    logger.error "dispatcher abort: pid=#{$$}"
    raise
  end
end

.new_logger(path, config) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 82

def Dispatcher.new_logger(path, config)
  Logger.new(
    device: path,
    rotation_period: config.fetch('log-rotation-period', 'daily'),
    rotation_size: config.fetch('log-rotation-size', nil)
  )
end

Instance Method Details

#after_message_batch ⇒ Object

override



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 122

def after_message_batch
  # must be processed first
  @event_queue.process_async_delete

  if @dispatch_requested
    logger.info "*** dispatch requested"
    do_handle_dispatch
    @dispatch_requested = false
  end

  if @checkpoint_requested
    do_handle_checkpoint
    @checkpoint_requested = false   # is needless, but reset it just in case
  end
end

#dispatch_tasks(tasks) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 208

def dispatch_tasks(tasks)
  tasks.each do |task|
    msg = StreamingLoadV3LoaderMessage.for_load_task(task)
    @task_queue.put msg
    @task_logger.log task
  end
end

#do_handle_checkpoint ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 158

def do_handle_checkpoint
  logger.info "*** checkpoint requested"
  logger.info "Force-flushing all objects..."
  tasks = @chunk_buffer.flush_all
  dispatch_tasks tasks
  logger.info "All objects flushed; shutting down..."
  @event_queue.initiate_terminate
end

#do_handle_dispatch ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 186

def do_handle_dispatch
  tasks = @chunk_buffer.flush_partial
  dispatch_tasks tasks
  set_dispatch_timer
end

#event_loop ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 113

def event_loop
  logger.info "*** dispatcher started: pid=#{$$}"
  set_dispatch_timer
  @event_queue.handle_messages(handler: self, message_class: DispatcherMessage)
  @event_queue.process_async_delete_force
  logger.info "*** shutdown gracefully: pid=#{$$}"
end

#handle_checkpoint(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 150

def handle_checkpoint(msg)
  # Delay creating CHECKPOINT after the current message batch,
  # because any other extra events are already received.
  @checkpoint_requested = true
  # Delete this event immediately
  @event_queue.delete_message(msg)
end

#handle_data(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 167

def handle_data(msg)
  unless msg.created_event?
    @event_queue.delete_message_async(msg)
    return
  end
  chunk = @chunk_router.route(msg)
  @chunk_buffer.save(chunk)
  @event_queue.delete_message_async(msg)
end

#handle_dispatch(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 177

def handle_dispatch(msg)
  # Dispatching tasks may takes 10 minutes or more, it can exceeds visibility timeout.
  # To avoid this, delay dispatching until all events of current message batch are processed.
  if @dispatch_message_id == msg.message_id
    @dispatch_requested = true
  end
  @event_queue.delete_message_async(msg)
end

#handle_flushtable(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 197

def handle_flushtable(msg)
  # FIXME: badly named attribute. table_name is really stream_name, which is called as data_source_id, too.
  stream_name = msg.table_name

  logger.info "*** flushtable requested: stream_name=#{stream_name}"
  tasks = @chunk_buffer.flush_stream(stream_name)
  dispatch_tasks tasks
  # Delete this event immediately
  @event_queue.delete_message(msg)
end

#handle_shutdown(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 143

def handle_shutdown(msg)
  logger.info "*** shutdown requested"
  @event_queue.initiate_terminate
  # Delete this event immediately
  @event_queue.delete_message(msg)
end

#handle_unknown(msg) ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 138

def handle_unknown(msg)
  logger.warn "unknown event: #{msg.message_body}"
  @event_queue.delete_message_async(msg)
end

#set_dispatch_timer ⇒ Object 



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# File 'lib/bricolage/streamingload/dispatcher.rb', line 192

def set_dispatch_timer
  res = @event_queue.send_message(DispatchDispatcherMessage.create(delay_seconds: @dispatch_interval))
  @dispatch_message_id = res.message_id
end