Class: EventQ::RabbitMq::QueueWorkerV2

Inherits:
Object
  • Object
show all
Includes:
WorkerId
Defined in:
lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ QueueWorkerV2

Returns a new instance of QueueWorkerV2.



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 8

def initialize
  @forks = []
  @is_running = false

  @retry_exceeded_block = nil
  @on_retry_block = nil
  @on_error_block = nil
  @hash_helper = HashKit::Helper.new
  @serialization_provider_manager = EventQ::SerializationProviders::Manager.new
  @signature_provider_manager = EventQ::SignatureProviders::Manager.new
end

Instance Attribute Details

#is_running ⇒ Object

Returns the value of attribute is_running.



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 6

def is_running
  @is_running
end

Instance Method Details

#call_on_error_block(error:, message: nil) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 103

def call_on_error_block(error:, message: nil)
  if @on_error_block
    EventQ.logger.debug { "[#{self.class}] - Executing on_error block." }
    begin
      @on_error_block.call(error, message)
    rescue => e
      EventQ.logger.error("[#{self.class}] - An error occurred executing the on_error block. Error: #{e}")
    end
  else
    EventQ.logger.debug { "[#{self.class}] - No on_error block specified to execute." }
  end
end

#call_on_retry_block(message) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 172

def call_on_retry_block(message)
  if @on_retry_block
    EventQ.logger.debug { "[#{self.class}] - Executing on_retry block." }
    begin
      @on_retry_block.call(message, abort)
    rescue => e
      EventQ.logger.error("[#{self.class}] - An error occurred executing the on_retry block. Error: #{e}")
    end
  else
    EventQ.logger.debug { "[#{self.class}] - No on_retry block specified." }
  end
end

#call_on_retry_exceeded_block(message) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 159

def call_on_retry_exceeded_block(message)
  if @retry_exceeded_block != nil
    EventQ.logger.debug { "[#{self.class}] - Executing on_retry_exceeded block." }
    begin
      @retry_exceeded_block.call(message)
    rescue => e
      EventQ.logger.error("[#{self.class}] - An error occurred executing the on_retry_exceeded block. Error: #{e}")
    end
  else
    EventQ.logger.debug { "[#{self.class}] - No on_retry_exceeded block specified." }
  end
end

#configure(queue, options = {}) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 227

def configure(queue, options = {})
  @queue = queue

  if options.key?(:thread_count)
    EventQ.logger.warn("[#{self.class}] - :thread_count is deprecated.")
  end

  if options.key?(:sleep)
    EventQ.logger.warn("[#{self.class}] - :sleep is deprecated.")
  end

  @fork_count = 1
  if options.key?(:fork_count)
    @fork_count = options[:fork_count]
  end

  EventQ.logger.info(
    "[#{self.class}] - Configuring. Process Count: #{@fork_count}."
  )

  return true
end

#deserialize_message(payload) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 149

def deserialize_message(payload)
  provider = @serialization_provider_manager.get_provider(EventQ::Configuration.serialization_provider)
  return provider.deserialize(payload)
end

#on_error(&block) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 140

def on_error(&block)
  @on_error_block = block
  return nil
end

#on_retry(&block) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 135

def on_retry(&block)
  @on_retry_block = block
  return nil
end

#on_retry_exceeded(&block) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 130

def on_retry_exceeded(&block)
  @retry_exceeded_block = block
  return nil
end

#reject_message(channel, message, delivery_tag, retry_exchange, queue, abort) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 185

def reject_message(channel, message, delivery_tag, retry_exchange, queue, abort)
  EventQ.logger.info("[#{self.class}] - Message rejected removing from queue.")
  # reject the message to remove from queue
  channel.reject(delivery_tag, false)

  # check if the message retry limit has been exceeded
  if message.retry_attempts >= queue.max_retry_attempts

    EventQ.logger.info("[#{self.class}] - Message retry attempt limit exceeded. Msg: #{serialize_message(message)}")

    call_on_retry_exceeded_block(message)

  # check if the message is allowed to be retried
  elsif queue.allow_retry
    EventQ.logger.debug { "[#{self.class}] - Incrementing retry attempts count." }
    message.retry_attempts += 1

    if queue.allow_retry_back_off == true
      EventQ.logger.debug do
        "[#{self.class}] - Calculating message back off retry delay. "\
"Attempts: #{message.retry_attempts} * Retry Delay: #{queue.retry_delay}"
      end
      message_ttl = message.retry_attempts * queue.retry_delay
      if (message.retry_attempts * queue.retry_delay) > queue.max_retry_delay
        EventQ.logger.debug { "[#{self.class}] - Max message back off retry delay reached." }
        message_ttl = queue.max_retry_delay
      end
    else
      EventQ.logger.debug { "[#{self.class}] - Setting fixed retry delay for message." }
      message_ttl = queue.retry_delay
    end

    EventQ.logger.debug { "[#{self.class}] - Sending message for retry. Message TTL: #{message_ttl}" }
    retry_exchange.publish(serialize_message(message), :expiration => message_ttl)
    EventQ.logger.debug { "[#{self.class}] - Published message to retry exchange." }

    call_on_retry_block(message)
  end

  return true
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 145

def running?
  return @is_running
end

#serialize_message(msg) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 154

def serialize_message(msg)
  provider = @serialization_provider_manager.get_provider(EventQ::Configuration.serialization_provider)
  return provider.serialize(msg)
end

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



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 20

def start(queue, options = {}, &block)

  EventQ.logger.info("[#{self.class}] - Preparing to start listening for messages.")

  configure(queue, options)

  raise "[#{self.class}] - Worker is already running." if running?

  if options[:client] == nil
    raise "[#{self.class}] - :client (QueueClient) must be specified."
  end

  EventQ.logger.info("[#{self.class}] - Listening for messages.")
  EventQ.logger.debug do
    "[#{self.class} #start] - Listening for messages on queue: #{EventQ.create_queue_name(queue.name)}"
  end

  @forks = []

  if @fork_count > 1
    Thread.new do
      @fork_count.times do
        pid = fork do
          start_process(options, queue, block)
        end
        @forks.push(pid)
      end
      @forks.each { |pid| Process.wait(pid) }
    end
  else
    start_process(options, queue, block)
  end
end

#start_process(options, queue, block) ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 54

def start_process(options, queue, block)
  @is_running = true

  %w'INT TERM'.each do |sig|
    Signal.trap(sig) {
      stop
      exit
    }
  end

  if !options.key?(:durable)
    options[:durable] = true
  end

  client = options[:client].dup
  manager = EventQ::RabbitMq::QueueManager.new
  manager.durable = options[:durable]
  @connection = client.get_connection

  channel = @connection.create_channel
  channel.prefetch(1)

  q = manager.get_queue(channel, queue)
  retry_exchange = manager.get_retry_exchange(channel, queue)

  q.subscribe(:manual_ack => true, :block => false, :exclusive => false) do |delivery_info, properties, payload|
    begin
      tag_processing_thread
      process_message(payload, queue, channel, retry_exchange, delivery_info.delivery_tag, block)
    rescue => e
      EventQ.logger.error(
        "[#{self.class}] - An error occurred attempting to process a message. Error: #{e} | "\
"Backtrace: #{e.backtrace}"
      )
      call_on_error_block(error: e)
    ensure
      untag_processing_thread
    end
  end

  if (options.key?(:wait) && options[:wait] == true) || (options.key?(:fork_count) && options[:fork_count] > 1)
    while running? do
      sleep 5
    end
  end

  return true
end

#stop ⇒ Object 



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# File 'lib/eventq_rabbitmq/rabbitmq_queue_worker_v2.rb', line 116

def stop
  EventQ.logger.info { "[#{self.class}] - Stopping..." }
  @is_running = false

  unless @connection.nil?
    begin
      @connection.close if @connection.open?
    rescue Timeout::Error
      EventQ.logger.error { 'Timeout occurred closing connection.' }
    end
  end
  return true
end