jdgoldie / akka-persistence-shared-inmemory   1.0.14

Deprecation Warning

This project has been deprecated by the addition of the Persistence Plugin Proxy which accomplishes the same function in conjunction with existing storage plugins. Thanks to the Akka Team for adding this feature to the core of Persistence.

Overview

This project contains in-memory implementations of the journal and snapshot store for akka-persistence that are designed to work with multi-node and single-node unit tests. Since all data is kept in memory structures, there are no side effects or cleanup between test runs. These plugins are tested against akka-persistence-tck-experimental version 2.3.9

Adding to your project

Add a resolver:

defaultResolvers += ("jdgoldie at bintray" at "http://dl.bintray.com/jdgoldie/maven")

and the dependency:

  "com.github.jdgoldie" %% "akka-persistence-shared-inmemory" % "1.0.16"

Use in a single node test

To use the journal and snapshot store in a basic unit test, add the following configuration to your application.conf:

  akka {
    persistence {
      journal {
        plugin = "akka.persistence.inmem.journal"
      }
      snapshot-store {
        plugin = "akka.persistence.inmem.snapshot-store"
      }
    }
  }

Use in a multi-node test

Using the journal and snapshot store in shared mode with a multi-node test requires a little more work. The configuration is:

persistence {
  journal {
    plugin = "akka.persistence.inmem.shared-journal"
  }
  snapshot-store {
    plugin = "akka.persistence.inmem.shared-snapshot-store"
  }
}

These plugins are only proxies to the actual stores, however, and must be configured further. In the multi-jvm tests, ExampleMultiJvmTestSpec.scala has an example of the additional configuration:

Persistence(system)

runOn(node1) {
  SharedInMemoryJournal.setStore(system.actorOf(
      Props[SharedInMemoryMessageStore], "journalStore"), system)
}

runOn(node2) {
  SharedInMemoryJournal.setStore(getActorRef(
      node(node1) / "user" / "journalStore").get, system)
}

On node1, the journalStore actor is created and the plugin-proxy is given a reference. On node2, the plugin-proxy is given a reference to the journalStore actor on node1.

The shared snapshot store is configured in a similar way. An example can be found in ExampleMultiJvmTestSpec.scala as well:

runOn(node1) {
  Persistence(system).snapshotStoreFor(null) ! 
      SharedInMemorySnapshotStore.SetStore(
          system.actorOf(Props[InMemorySnapshotStore], "snapStore"))
}

runOn(node2) {
  Persistence(system).snapshotStoreFor(null) ! 
      SharedInMemorySnapshotStore.SetStore(
          getActorRef(node(node1) / "user" / "snapStore").get)
}

Acknowledgements

The design for the shared plugins is heavily based on the shared LevelDB journal in akka-persistence. The shared journal test is ported from the shared LevelDB journal test from the same source.

Thanks to OneGeek for the article on TravisCi-to-Bintray setup