Class: Fluent::KafkaGroupInput

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

Defined Under Namespace

Classes: ForShutdown

Constant Summary collapse

BufferError = 
if defined?(Fluent::Plugin::Buffer::BufferOverflowError)
  Fluent::Plugin::Buffer::BufferOverflowError
else
  Fluent::BufferQueueLimitError
end

Constants included from Fluent::KafkaPluginUtil::SSLSettings

Fluent::KafkaPluginUtil::SSLSettings::DummyFormatter

Instance Method Summary collapse

Methods included from Fluent::KafkaPluginUtil::SaslSettings

included

Methods included from Fluent::KafkaPluginUtil::SSLSettings

included, #pickup_ssl_endpoint, #read_ssl_file

Constructor Details

#initialize ⇒ KafkaGroupInput

Returns a new instance of KafkaGroupInput.



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 73

def initialize
  super
  require 'kafka'

  @time_parser = nil
  @retry_count = 1
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 95

def configure(conf)
  super

  $log.info "Will watch for topics #{@topics} at brokers " \
            "#{@brokers} and '#{@consumer_group}' group"

  @topics = _config_to_array(@topics)

  if conf['max_wait_ms']
    log.warn "'max_wait_ms' parameter is deprecated. Use second unit 'max_wait_time' instead"
    @max_wait_time = conf['max_wait_ms'].to_i / 1000
  end

  @parser_proc = setup_parser

  @consumer_opts = {:group_id => @consumer_group}
  @consumer_opts[:session_timeout] = @session_timeout if @session_timeout
  @consumer_opts[:offset_commit_interval] = @offset_commit_interval if @offset_commit_interval
  @consumer_opts[:offset_commit_threshold] = @offset_commit_threshold if @offset_commit_threshold
  @consumer_opts[:fetcher_max_queue_size] = @fetcher_max_queue_size if @fetcher_max_queue_size

  @fetch_opts = {}
  @fetch_opts[:max_wait_time] = @max_wait_time if @max_wait_time
  @fetch_opts[:min_bytes] = @min_bytes if @min_bytes

  if @use_record_time and @time_format
    if defined?(Fluent::TimeParser)
      @time_parser = Fluent::TimeParser.new(@time_format)
    else
      @time_parser = Fluent::TextParser::TimeParser.new(@time_format)
    end
  end
end

#emit_events(tag, es) ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 262

def emit_events(tag, es)
  retries = 0
  begin
    router.emit_stream(tag, es)
  rescue BufferError
    raise ForShutdown if @consumer.nil?

    if @retry_emit_limit.nil?
      sleep 1
      retry
    end

    if retries < @retry_emit_limit
      retries += 1
      sleep 1
      retry
    else
      raise RuntimeError, "Exceeds retry_emit_limit"
    end
  end
end

#multi_workers_ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/in_kafka_group.rb', line 89

def multi_workers_ready?
  true
end

#reconnect_consumer ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 194

def reconnect_consumer
  log.warn "Stopping Consumer"
  consumer = @consumer
  @consumer = nil
  if consumer
    consumer.stop
  end
  log.warn "Could not connect to broker. retry_time:#{@retry_count}. Next retry will be in #{@retry_wait_seconds} seconds"
  @retry_count = @retry_count + 1
  sleep @retry_wait_seconds
  @consumer = setup_consumer
  log.warn "Re-starting consumer #{Time.now.to_s}"
  @retry_count = 0
rescue =>e
  log.error "unexpected error during re-starting consumer object access", :error => e.to_s
  log.error_backtrace
  if @retry_count <= @retry_limit or disable_retry_limit
    reconnect_consumer
  end
end

#run ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 215

def run
  while @consumer
    begin
      @consumer.each_batch(@fetch_opts) { |batch|
        es = Fluent::MultiEventStream.new
        tag = batch.topic
        tag = @add_prefix + "." + tag if @add_prefix
        tag = tag + "." + @add_suffix if @add_suffix

        batch.messages.each { |msg|
          begin
            record = @parser_proc.call(msg)
            if @use_record_time
              if @time_format
                record_time = @time_parser.parse(record['time'].to_s)
              else
                record_time = record['time']
              end
            else
              record_time = Fluent::Engine.now
            end
            if @kafka_message_key
              record[@kafka_message_key] = msg.key
            end
            es.add(record_time, record)
          rescue => e
            log.warn "parser error in #{batch.topic}/#{batch.partition}", :error => e.to_s, :value => msg.value, :offset => msg.offset
            log.debug_backtrace
          end
        }

        unless es.empty?
          emit_events(tag, es)
        end
      }
    rescue ForShutdown
    rescue => e
      log.error "unexpected error during consuming events from kafka. Re-fetch events.", :error => e.to_s
      log.error_backtrace
      reconnect_consumer
    end
  end
rescue => e
  log.error "unexpected error during consumer object access", :error => e.to_s
  log.error_backtrace
end

#setup_consumer ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 186

def setup_consumer
  consumer = @kafka.consumer(@consumer_opts)
  @topics.each { |topic|
    consumer.subscribe(topic, start_from_beginning: @start_from_beginning, max_bytes_per_partition: @max_bytes)
  }
  consumer
end

#setup_parser ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 129

def setup_parser
  case @format
  when 'json'
    begin
      require 'oj'
      Oj.default_options = Fluent::DEFAULT_OJ_OPTIONS
      Proc.new { |msg| Oj.load(msg.value) }
    rescue LoadError
      require 'yajl'
      Proc.new { |msg| Yajl::Parser.parse(msg.value) }
    end
  when 'ltsv'
    require 'ltsv'
    Proc.new { |msg| LTSV.parse(msg.value, {:symbolize_keys => false}).first }
  when 'msgpack'
    require 'msgpack'
    Proc.new { |msg| MessagePack.unpack(msg.value) }
  when 'text'
    Proc.new { |msg| {@message_key => msg.value} }
  end
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 173

def shutdown
  # This nil assignment should be guarded by mutex in multithread programming manner.
  # But the situation is very low contention, so we don't use mutex for now.
  # If the problem happens, we will add a guard for consumer.
  consumer = @consumer
  @consumer = nil
  consumer.stop

  @thread.join
  @kafka.close
  super
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/in_kafka_group.rb', line 151

def start
  super

  if @scram_mechanism != nil && @username != nil && @password != nil
    @kafka = Kafka.new(seed_brokers: @brokers, client_id: @client_id, logger: log, 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),
                       ssl_ca_certs_from_system: @ssl_ca_certs_from_system, sasl_scram_username: @username, sasl_scram_password: @password,
                       sasl_scram_mechanism: @scram_mechanism, sasl_over_ssl: @sasl_over_ssl)
  elsif @username != nil && @password != nil
    @kafka = Kafka.new(seed_brokers: @brokers, client_id: @client_id, logger: log, 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),
                       ssl_ca_certs_from_system: @ssl_ca_certs_from_system, sasl_plain_username: @username, sasl_plain_password: @password)
  else
    @kafka = Kafka.new(seed_brokers: @brokers, client_id: @client_id, logger: log, 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),
                       ssl_ca_certs_from_system: @ssl_ca_certs_from_system, sasl_gssapi_principal: @principal, sasl_gssapi_keytab: @keytab)
  end

  @consumer = setup_consumer
  @thread = Thread.new(&method(:run))
end