Akka/Scala example source code file (reference.conf)

This example Akka source code file (reference.conf) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

class, dispatcher, interval, java, jni, leveldb, maximum, native, path, storage

The reference.conf Akka example source code

##########################################
# Akka Persistence Reference Config File #
##########################################



akka {

  # Protobuf serialization for persistent messages
  actor {

    serializers {

      akka-persistence-snapshot = "akka.persistence.serialization.SnapshotSerializer"
      akka-persistence-message = "akka.persistence.serialization.MessageSerializer"
    }

    serialization-bindings {

      "akka.persistence.serialization.Snapshot" = akka-persistence-snapshot
      "akka.persistence.serialization.Message" = akka-persistence-message
    }
  }

  persistence {

    journal {

      # Maximum size of a persistent message batch written to the journal.
      max-message-batch-size = 200

      # Maximum size of a confirmation batch written to the journal.
      max-confirmation-batch-size = 10000

      # Maximum size of a deletion batch written to the journal.
      max-deletion-batch-size = 10000

      # Path to the journal plugin to be used
      plugin = "akka.persistence.journal.leveldb"

      # In-memory journal plugin.
      inmem {

        # Class name of the plugin.
        class = "akka.persistence.journal.inmem.InmemJournal"

        # Dispatcher for the plugin actor.
        plugin-dispatcher = "akka.actor.default-dispatcher"
      }

      # LevelDB journal plugin.
      leveldb {

        # Class name of the plugin.
        class = "akka.persistence.journal.leveldb.LeveldbJournal"

        # Dispatcher for the plugin actor.
        plugin-dispatcher = "akka.persistence.dispatchers.default-plugin-dispatcher"

        # Dispatcher for message replay.
        replay-dispatcher = "akka.persistence.dispatchers.default-replay-dispatcher"

        # Storage location of LevelDB files.
        dir = "journal"

        # Use fsync on write
        fsync = on

        # Verify checksum on read.
        checksum = off

        # Native LevelDB (via JNI) or LevelDB Java port
        native = on
      }

      # Shared LevelDB journal plugin (for testing only).
      leveldb-shared {

        # Class name of the plugin.
        class = "akka.persistence.journal.leveldb.SharedLeveldbJournal"

        # Dispatcher for the plugin actor.
        plugin-dispatcher = "akka.actor.default-dispatcher"
        
        # timeout for async journal operations
        timeout = 10s

        store {

          # Dispatcher for shared store actor.
          store-dispatcher = "akka.persistence.dispatchers.default-plugin-dispatcher"

          # Dispatcher for message replay.
          replay-dispatcher = "akka.persistence.dispatchers.default-plugin-dispatcher"

          # Storage location of LevelDB files.
          dir = "journal"

          # Use fsync on write
          fsync = on

          # Verify checksum on read.
          checksum = off

          # Native LevelDB (via JNI) or LevelDB Java port
          native = on
        }
      }
    }

    snapshot-store {

      # Path to the snapshot store plugin to be used
      plugin = "akka.persistence.snapshot-store.local"

      # Local filesystem snapshot store plugin.
      local {

        # Class name of the plugin.
        class = "akka.persistence.snapshot.local.LocalSnapshotStore"

        # Dispatcher for the plugin actor.
        plugin-dispatcher = "akka.persistence.dispatchers.default-plugin-dispatcher"

        # Dispatcher for streaming snapshot IO.
        stream-dispatcher = "akka.persistence.dispatchers.default-stream-dispatcher"

        # Storage location of snapshot files.
        dir = "snapshots"
      }
    }

    view {

      # Automated incremental view update.
      auto-update = on

      # Interval between incremental updates
      auto-update-interval = 5s

      # Maximum number of messages to replay per incremental view update. Set to
      # -1 for no upper limit.
      auto-update-replay-max = -1
    }
    
    at-least-once-delivery {
      # Interval between redelivery attempts
      redeliver-interval = 5s
      
      # After this number of delivery attempts a `ReliableRedelivery.UnconfirmedWarning`
      # message will be sent to the actor.
      warn-after-number-of-unconfirmed-attempts = 5
      
      # Maximum number of unconfirmed messages that an actor with AtLeastOnceDelivery is
      # allowed to hold in memory.
      max-unconfirmed-messages = 100000
    }

    dispatchers {
      default-plugin-dispatcher {
        type = PinnedDispatcher
        executor = "thread-pool-executor"
      }
      default-replay-dispatcher {
        type = Dispatcher
        executor = "fork-join-executor"
        fork-join-executor {
          parallelism-min = 2
          parallelism-max = 8
        }
      }
      default-stream-dispatcher {
        type = Dispatcher
        executor = "fork-join-executor"
        fork-join-executor {
          parallelism-min = 2
          parallelism-max = 8
        }
      }
    }
  }
}