Class: Fluent::Kafka2Output

Inherits:
Output
  • Object
show all
Includes:
Fluent::KafkaPluginUtil::SSLSettings, Fluent::KafkaPluginUtil::SaslSettings
Defined in:
lib/fluent/plugin/out_kafka2.rb

Instance Method Summary collapse

Methods included from Fluent::KafkaPluginUtil::SaslSettings

included

Methods included from Fluent::KafkaPluginUtil::SSLSettings

included, #read_ssl_file

Constructor Details

#initialize ⇒ Kafka2Output

Returns a new instance of Kafka2Output.



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# File 'lib/fluent/plugin/out_kafka2.rb', line 64

def initialize
  super

  @kafka = nil
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 149

def close
  super
  @kafka.close if @kafka
end

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 98

def configure(conf)
  super

  if @brokers.size > 0
    log.info "brokers has been set: #{@brokers}"
  else
    raise Fluent::Config, 'No brokers specified. Need one broker at least.'
  end

  formatter_conf = conf.elements('format').first
  unless formatter_conf
    raise Fluent::ConfigError, "<format> section is required."
  end
  unless formatter_conf["@type"]
    raise Fluent::ConfigError, "format/@type is required."
  end
  @formatter_proc = setup_formatter(formatter_conf)

  if @default_topic.nil?
    if @chunk_keys.include?('topic') && !@chunk_keys.include?('tag')
      log.warn "Use 'topic' field of event record for topic but no fallback. Recommend to set default_topic or set 'tag' in buffer chunk keys like <buffer topic,tag>"
    end
  else
    if @chunk_keys.include?('tag')
      log.warn "default_topic is set. Fluentd's event tag is not used for topic"
    end
  end

  @producer_opts = {max_retries: @max_send_retries, required_acks: @required_acks}
  @producer_opts[:ack_timeout] = @ack_timeout if @ack_timeout
  @producer_opts[:compression_codec] = @compression_codec.to_sym if @compression_codec
  if @active_support_notification_regex
    require 'active_support/notifications'
    require 'active_support/core_ext/hash/keys'
    ActiveSupport::Notifications.subscribe(Regexp.new(@active_support_notification_regex)) do |*args|
      event = ActiveSupport::Notifications::Event.new(*args)
      message = event.payload.respond_to?(:stringify_keys) ? event.payload.stringify_keys : event.payload
      @router.emit("fluent_kafka_stats.#{event.name}", Time.now.to_i, message)
    end
  end
end

#multi_workers_ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/out_kafka2.rb', line 140

def multi_workers_ready?
  true
end

#refresh_client(raise_error = true) ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 70

def refresh_client(raise_error = true)
  begin
    logger = @get_kafka_client_log ? log : nil
    if @scram_mechanism != nil && @username != nil && @password != nil
      log.info "using scram authentication"
      @kafka = Kafka.new(seed_brokers: @seed_brokers, client_id: @client_id, ssl_ca_cert: read_ssl_file(@ssl_ca_cert),
                         ssl_client_cert: read_ssl_file(@ssl_client_cert), ssl_client_cert_key: read_ssl_file(@ssl_client_cert_key),
                         sasl_scram_username: @username, sasl_scram_password: @password, sasl_scram_mechanism: @scram_mechanism)
    elseif @username != nil && @password != nil
      log.info "using plain authentication"
      @kafka = Kafka.new(seed_brokers: @seed_brokers, client_id: @client_id, ssl_ca_cert: read_ssl_file(@ssl_ca_cert),
                         ssl_client_cert: read_ssl_file(@ssl_client_cert), ssl_client_cert_key: read_ssl_file(@ssl_client_cert_key),
                         sasl_plain_username: @username, sasl_plain_password: @password)
    else
      @kafka = Kafka.new(seed_brokers: @seed_brokers, client_id: @client_id, ssl_ca_cert: read_ssl_file(@ssl_ca_cert),
                         ssl_client_cert: read_ssl_file(@ssl_client_cert), ssl_client_cert_key: read_ssl_file(@ssl_client_cert_key),
                         sasl_gssapi_principal: @principal, sasl_gssapi_keytab: @keytab)
    end
    log.info "initialized kafka producer: #{@client_id}"
  rescue Exception => e
    if raise_error # During startup, error should be reported to engine and stop its phase for safety.
      raise e
    else
      log.error e
    end
  end
end

#setup_formatter(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 159

def setup_formatter(conf)
  type = conf['@type']
  case type
  when 'json'
    begin
      require 'oj'
      Oj.default_options = Fluent::DEFAULT_OJ_OPTIONS
      Proc.new { |tag, time, record| Oj.dump(record) }
    rescue LoadError
      require 'yajl'
      Proc.new { |tag, time, record| Yajl::Encoder.encode(record) }
    end
  when 'ltsv'
    require 'ltsv'
    Proc.new { |tag, time, record| LTSV.dump(record) }
  else
    @formatter = formatter_create(usage: 'kafka-plugin', conf: conf)
    @formatter.method(:format)
  end
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 144

def start
  super
  refresh_client
end

#terminate ⇒ Object 



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# File 'lib/fluent/plugin/out_kafka2.rb', line 154

def terminate
  super
  @kafka = nil
end

#write(chunk) ⇒ Object

TODO: optimize write performance



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# File 'lib/fluent/plugin/out_kafka2.rb', line 181

def write(chunk)
  tag = chunk.metadata.tag
  topic = chunk.metadata.variables[:topic] || @default_topic || tag
  producer = @kafka.topic_producer(topic, @producer_opts)

  messages = 0
  record_buf = nil

  begin
    chunk.msgpack_each { |time, record|
      begin
        record = inject_values_to_record(tag, time, record)
        record.delete('topic'.freeze) if @exclude_topic_key
        partition_key = (@exclude_partition_key ? record.delete('partition_key'.freeze) : record['partition_key'.freeze]) || @default_partition_key
        partition = (@exclude_partition ? record.delete('partition'.freeze) : record['partition'.freeze]) || @default_partition
        message_key = (@exclude_message_key ? record.delete('message_key'.freeze) : record['message_key'.freeze]) || @default_message_key

        record_buf = @formatter_proc.call(tag, time, record)
      rescue StandardError => e
        log.warn "unexpected error during format record. Skip broken event:", :error => e.to_s, :error_class => e.class.to_s, :time => time, :record => record
        next
      end

      log.trace { "message will send to #{topic} with partition_key: #{partition_key}, partition: #{partition}, message_key: #{message_key} and value: #{record_buf}." }
      messages += 1

      producer.produce(record_buf, message_key, partition, partition_key)
    }

    if messages > 0
      log.debug { "#{messages} messages send." }
      producer.deliver_messages
    end
  end
rescue Exception => e
  log.warn "Send exception occurred: #{e}"
  log.warn "Exception Backtrace : #{e.backtrace.join("\n")}"
  # For safety, refresh client and its producers
  refresh_client(false)
  # Raise exception to retry sendind messages
  raise e
ensure
  producer.shutdown if producer
end