I have state stored aggregates in a PostgreSQL database. I'm testing replay by deleting the state stored tables and the token_entry table and restarting the application. All events will be replayed and aggregates are restored in-memory. However, my state stored tables stay empty. I was thinking that they would also be restored?

I'm using SpringBoot and latest Axon. The code, at this moment, is as simple as it can get.

CodePudding user response：

Whenever you're using Axon's State-Stored Aggregates, they'll only be stored as-is. Hence, throwing away the stored instances and starting the application will not trigger a replay.

When removing TrackingTokens, or initiating a replay by invoking StreamingEventProcessor#resetTokens (this is the recommended approach, by the way), you're effectively telling the Event Processors of your application to start event streaming from scratch.

This part of Axon Framework supports the so-called Query Side of CQRS. The Aggregate support in Axon Framework is specifically for the Command Side of an application.

Long story short, State-Stored Aggregates don't have replay support. If you want your Aggregates (Command Models) to be replayed, you will have to use Event Sourcing Aggregates instead.

I hope the above clarifies a little about the misconception between Token and Aggregates from your question. And by the way, if you feel Axon's Reference Guide should be adjusted to clarify your situation, you're always free to file an issue.