PersistenceLifecycleEvent not sent to typed actor

Hi! Is there a way to hook in to PersistenceLifecycleEvent in typed actors? I’ve looked at https://github.com/Horusiath/Akkling/issues/72 and the test, but this seems only to work for untyped actors. Here is a fork with the same test for a typed actor (Eventsourced<string>), and it currently fails: https://github.com/Yakimych/Akkling/commit/c9dc995e6479f952d2cda973b4c6b2808318b42b

My guess is that typed actors don’t receive messages of anything but the specified type, so I am wondering if this is possible at all.

[Horusiath]

I think the reason here is that your persistence provider uses some configuration of JSON.NET, that doesn’t support type name handling. There are two problems:

1. Without type name handling, JSON.NET serializer won’t know what object should it deserialize when serializer.DeserializeObject<obj> is called.
2. With type name handling turned on, a fully qualified type name is used. So if you ever change the type name or namespace in the future, it won’t be able to deserialize it back.

Usually when it comes to persistent serialization, I suggest people to write their own custom serializers (using eg. protobuf, FsPickler or whatever you want), to have full control of binary format and how it changes over time.

[Horusiath]

From what I see, you’re using Json.NET for persistence - this may be the reason, when trying to deserialize json payload into obj it doesn’t know what specific type of object do you want - which in this case it will default to JDocument or JObject.

This is continuous problem of using JSON.NET, and one of the reasons why we started using Hyperion - but problem with Hyperion is that it’s binary format is not stabilized and it doesn’t provide any guarantees, that future version will keep it backwards compatible.