Configuration

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# Akka Stream Reference Config File #
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akka {
  stream {

    # Default flow materializer settings
    materializer {

      # Initial size of buffers used in stream elements
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      initial-input-buffer-size = 4

      # Maximum size of buffers used in stream elements
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      max-input-buffer-size = 16

      # Fully qualified config path which holds the dispatcher configuration
      # to be used by FlowMaterialiser when creating Actors.
      # When this value is left empty, the default-dispatcher will be used.
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      dispatcher = ""

      # Cleanup leaked publishers and subscribers when they are not used within a given
      # deadline
      subscription-timeout {
        # when the subscription timeout is reached one of the following strategies on
        # the "stale" publisher:
        # cancel - cancel it (via `onError` or subscribing to the publisher and
        #          `cancel()`ing the subscription right away
        # warn   - log a warning statement about the stale element (then drop the
        #          reference to it)
        # noop   - do nothing (not recommended)		
	    # Note: If you change this value also change the fallback value in StreamSubscriptionTimeoutSettings
        mode = cancel

        # time after which a subscriber / publisher is considered stale and eligible
        # for cancelation (see `akka.stream.subscription-timeout.mode`)		
	    # Note: If you change this value also change the fallback value in StreamSubscriptionTimeoutSettings
        timeout = 5s
      }
      
      # Enable additional troubleshooting logging at DEBUG log level
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      debug-logging = off

      # Maximum number of elements emitted in batch if downstream signals large demand
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      output-burst-limit = 1000
      
      # Enable automatic fusing of all graphs that are run. For short-lived streams
      # this may cause an initial runtime overhead, but most of the time fusing is
      # desirable since it reduces the number of Actors that are created.
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      auto-fusing = on

	  # Those stream elements which have explicit buffers (like mapAsync, mapAsyncUnordered,
      # buffer, flatMapMerge, Source.actorRef, Source.queue, etc.) will preallocate a fixed
      # buffer upon stream materialization if the requested buffer size is less than this
      # configuration parameter. The default is very high because failing early is better
      # than failing under load.
      #
      # Buffers sized larger than this will dynamically grow/shrink and consume more memory
      # per element than the fixed size buffers.
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
      max-fixed-buffer-size = 1000000000

	  # Maximum number of sync messages that actor can process for stream to substream communication.
	  # Parameter allows to interrupt synchronous processing to get upsteam/downstream messages.
	  # Allows to accelerate message processing that happening withing same actor but keep system responsive.
	  # Note: If you change this value also change the fallback value in ActorMaterializerSettings
	  sync-processing-limit = 1000

      debug {
        # Enables the fuzzing mode which increases the chance of race conditions
        # by aggressively reordering events and making certain operations more
        # concurrent than usual.
        # This setting is for testing purposes, NEVER enable this in a production
        # environment!
        # To get the best results, try combining this setting with a throughput
        # of 1 on the corresponding dispatchers.
	    # Note: If you change this value also change the fallback value in ActorMaterializerSettings
        fuzzing-mode = off
      }
    }

    # Fully qualified config path which holds the dispatcher configuration
    # to be used by FlowMaterialiser when creating Actors for IO operations,
    # such as FileSource, FileSink and others.
    blocking-io-dispatcher = "akka.stream.default-blocking-io-dispatcher"

    default-blocking-io-dispatcher {
      type = "Dispatcher"
      executor = "thread-pool-executor"
      throughput = 1

      thread-pool-executor {
        core-pool-size-min = 2
        core-pool-size-factor = 2.0
        core-pool-size-max = 16
      }
    }
  }

  # configure overrides to ssl-configuration here (to be used by akka-streams, and akka-http – i.e. when serving https connections)
  ssl-config {
    protocol = "TLSv1"
  }
}