Separate Event and Token/Saga Storage engine


I already had a discussion with Frans Van Buul on this topic, but he is on holiday at the moment so I hope someone else can help me with this.

In preparation of going to AxonDB, I would like to configure 2 storage engines:

  • 1 central event storage engine (MySQL)
  • 1 local saga&token storage engine (MySQL)

I almost got this working by following this example:

In the situation where the event store and the saga/token store is used in 1 transaction, I get the following message:

An event with identifier [f33ec3f2-99d2-4410-bea2-3ace46eea032] could not be persisted

Caused by: javax.persistence.TransactionRequiredException: no transaction is in progress

A concrete example: if you send an event from within a saga, the saga entry table needs to be changed and the event needs to be added in the database, this happens in the same transaction.
Only 1 transaction manager will be asked to create a transaction, and in this example the Event Store didnt start a transaction. For this reason, I got this exception.

If you work with AxonDb, the transactions will probably handled by AxonDb itself.
But in this case, I have 2 datasources … both are managed by two different transaction manager in this example.

Anyone a solution for this? Do I really need a distributed transactions for this?

Kind regards,
Koen Verwimp

Hi Koen,

you probably don’t really need a distributed transaction in your case, but at minimum just two transactions. If you’re writing to both data sources, you must ensure that a transaction is active for each of those sources. You can configure multiple TransactionManagingInterceptors for your components. By default, Axon will create one for you, assuming there is a single TransactionManager.

Hope this helps.



PS. It wasn’t only Frans who was on vacation, I guess :wink: