reference.conf

# Properties for akka.kafka.ProducerSettings can be
# defined in this section or a configuration section with
# the same layout. 
akka.kafka.producer {
  # Tuning parameter of how many sends that can run in parallel.
  parallelism = 5
  
  # How long to wait for `KafkaProducer.close`
  close-timeout = 60s
  
  # Fully qualified config path which holds the dispatcher configuration
  # to be used by the producer stages. Some blocking may occur.
  # When this value is empty, the dispatcher configured for the stream
  # will be used.
  use-dispatcher = "akka.kafka.default-dispatcher"

  # Properties defined by org.apache.kafka.clients.producer.ProducerConfig
  # can be defined in this configuration section.
  kafka-clients {
  }
}

# Properties for akka.kafka.ConsumerSettings can be
# defined in this section or a configuration section with
# the same layout. 
akka.kafka.consumer {
  # Tuning property of scheduled polls.
  poll-interval = 100ms
  
  # Tuning property of the `KafkaConsumer.poll` parameter.
  # Note that non-zero value means that blocking of the thread that
  # is executing the stage will be blocked.
  poll-timeout = 50ms
  
  # Tuning property of the `KafkaConsumer.poll` parameter when there
  # are outstanding offset commit requests.
  # Note that non-zero value means that blocking of the thread that
  # is executing the stage will be blocked.
  poll-commit-timeout = 1ms
  
  # The stage will be await outstanding offset commit requests before
  # shutting down, but if that takes longer than this timeout it will
  # stop forcefully.
  stop-timeout = 30s
  
  # How long to wait for `KafkaConsumer.close`
  close-timeout = 20s
  
  # If offset commit requests are not completed within this timeout
  # the returned Future is completed `TimeoutException`.
  commit-timeout = 15s
  
  # Fully qualified config path which holds the dispatcher configuration
  # to be used by the consumer stages. Some blocking may occur.
  # When this value is empty, the dispatcher configured for the stream
  # will be used.
  use-dispatcher = "akka.kafka.default-dispatcher"

  # Properties defined by org.apache.kafka.clients.consumer.ConsumerConfig
  # can be defined in this configuration section.
  kafka-clients {
    # Disable auto-commit by default
    enable.auto.commit = false
  }
}

# The dispatcher that will be used by default by consumer and
# producer stages.
akka.kafka.default-dispatcher {
  type = "Dispatcher"
  executor = "thread-pool-executor"

  thread-pool-executor {
    fixed-pool-size = 16
  }
}