__config processor_name

Hi,

A while back we upgraded the axonframework in our application.
Ever since we seems to have a processor with the name of __config in our token table in the database.
The token itself is something like this: {"config":{"id":"some-uuid"}}

What is this used for and do we need to be carefull with this when refreshing databases on lower environments with new data?

Kr

Tom.

Hi Tom,

That entry is a new entry, and it isn’t essential when transferring data to another database.
Axon uses this __config entry to distinguish between processors with the same name that compete for segments and those that both need to process them in parallel.

For example, when you have two instances of a projection, it might be that each of those projects into another database (for cross-regional availability, for example). In that case, you’d have 2 processors with the same name. AxonServer used to provide some warnings report that overlapping claims on segments existed.

With this identifier, Axon Server (or any monitoring tool that you may be using) will be able to recognize that these processors project into different destinations, as the tokenStoreIdentifier is different for each one of them.

When refreshing a database, you don’t need to take any special precautions for this element. It is automatically inserted at startup if it can’t be found.

We used this approach because it allows us to remain completely backward compatible with older versions of Axon.

I hope that clarifies it.