I wanted to inform the community of a solution we have just finished testing for the next XAF version in response to the following customer's business scenario:

"i followed this instruction to work with two databases in one application. so far so good. 

i also managed to include the security module and get it working, but now i don't know how to use the "audit trail" module! it doesn't seem to matter in which project i include it, but it will not save anything to the database."

As you probably know, XAF supports connecting to several databases and even using both Entity Framework (EF) and eXpress Persistent Objects (XPO) at the same time (examples: one, two, three), although it is not the primary scenario, to be honest. 

In short, if you were in need of such a configuration and wanted to have AuditTrail capabilities, it would "just work" starting with v15.1.6. If you feel confident to check technical details on this, see my description in the T263982 - AuditTrail - Ensure support for scenarios with several XPObjectSpaceProviders ticket.

By providing support for this module, we continue working in the direction we took in the past, which I also discussed in the past blog. As always, our team is looking forward to hearing your feedback in this regard.