Storage Plugins

Journals

Journal is a specialized type of actor which exposes an API to handle incoming events and store them in backend storage. By default Akka.Persistence uses a MemoryJournal which stores all events in memory and therefore it's not persistent storage. A custom journal configuration path may be specified inside akka.persistence.journal.plugin path and by default it requires two keys set: class and plugin-dispatcher. Example configuration:

    }
}

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# Persistence plugins included with the extension #
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Snapshot Store

Snapshot store is a specialized type of actor which exposes an API to handle incoming snapshot-related requests and is able to save snapshots in some backend storage. By default Akka.Persistence uses a LocalSnapshotStore, which uses a local file system as storage. A custom snapshot store configuration path may be specified inside akka.persistence.snapshot-store.plugin path and by default it requires two keys set: class and plugin-dispatcher. Example configuration:

akka.persistence.journal.inmem {
    # Class name of the plugin.
    class = "Akka.Persistence.Journal.MemoryJournal, Akka.Persistence"
    # Dispatcher for the plugin actor.
    plugin-dispatcher = "akka.actor.default-dispatcher"
}

Eager Initialization of Persistence Plugin

By default, persistence plugins are started on-demand, as they are used. In some case, however, it might be beneficial to start a certain plugin eagerly. In order to do that, specify the IDs of plugins you wish to start automatically under akka.persistence.journal.auto-start-journals and akka.persistence.snapshot-store.auto-start-snapshot-stores.

For example, if you want eager initialization for the sqlite journal and snapshot store plugin, your configuration should look like this:

akka {
  persistence {
    journal {
      plugin = "akka.persistence.journal.sqlite"
      auto-start-journals = ["akka.persistence.journal.sqlite"]
    }
    snapshot-store {
      plugin = "akka.persistence.snapshot-store.sqlite"
      auto-start-snapshot-stores = ["akka.persistence.snapshot-store.sqlite"]
    }
  }
}