Trouble with Identifier during migration from old akka version

I’m working on a project which uses an old version of akka persistence. There are custom serialisers with identifiers starting from 17 onwards. Later versions of akka have these Ids reserved so it is not possible to have duplicates.

Is there any way to update this identifier and still be able to decode the already existing old data?

It depends a bit on the journal plugin you are using, but usually the serializer id is stored in a separate column or field of some kind, in that case it is likely possible to choose new higher ids in the app and then do a pass over all entries in the database to update the serializer id fields before starting the system with the updated system. (It would need a full stop of the system while updating the database though)

thanks for the reply, we are using dynamodb plugin. okay, that would look something like: read everything using the existing version, write with a higher identifier then deploy the update.