Whirlwind Tour of Akka Typed

This demo project shows many of the features of Akka Typed, core ones as well as higher-level ones like for Akka Persistence or Akka Cluster.

The use case is a simple user repository. The architecture is based upon Event Sourcing and CQRS with a strictly consistent (CP) write side and an eventually consistent (AP) in-memory read model.

The below diagram shows the main components, most of which are actors.

                                    HTTP
+------------------------------------o---------------------------------+
|                                    |                                 |
|                                    |                                 |
|               AddUser              |                                 |
|               RemoveUser  +-----------------+    GetUsers            |
|              +----------->|       Api       |<-----------+           |
|              |            +-----------------+            |           |
|              v                                           v           |
|     +-----------------+             Changed     +-----------------+  |
|     | UserRepository  |            +----------->|    UserView     |  |
|     +-----------------+            |            +-----------------+  |
|              |                     |                                 |
|              |            +-----------------+                        |
|              |            |      DData      |                        |
|              |            +-----------------+                        |
|    UserAdded |                     ^                                 |
|  UserRemoved |                     |            +-----------------+  |
|              |                     +------------| UserProjection  |  |
|              |                      Update      +-----------------+  |
|              |                                           ^           |
|              |                                           |           |
+--------------+-------------------------------------------+-----------+
               v                                           |
      +-----------------+            Source[User.Event, _] |
      |    EventLog     |----------------------------------+
      +-----------------+

In order to run the system:

• make sure to have Cassandra up and running properly, e.g. via docker-compose up -d cassandra
• use correct configuration settings, e.g. by using the comman aliases r0 and r1 from within sbt

Contribution policy

Contributions via GitHub pull requests are gladly accepted from their original author. Along with any pull requests, please state that the contribution is your original work and that you license the work to the project under the project's open source license. Whether or not you state this explicitly, by submitting any copyrighted material via pull request, email, or other means you agree to license the material under the project's open source license and warrant that you have the legal authority to do so.

License

This code is open source software licensed under the Apache-2.0 license.