Multi-Tenancy with Spring + Hibernate: “SessionFactory configured for multi-tenancy, but no tenant identifier specified”

Question

In a Spring 3 application, I\'m trying to implement multi-tenancy via Hibernate 4\'s native MultiTenantConnectionProvider and CurrentTenantIdentifierResolver. I see that the

Answer 1

Foreward: Although I accepted this answer which (will) contains code, please upvote Darren's answer if you think this was useful. He's the reason I was able to solve this at all.

Okay, so here we go....

As Darren pointed out, this is really an issue with SessionFactory's instantiating a Session improperly. If you were to instantiate the session manually, you have no issue. eg:

sessionFactory.withOptions().tenantIdentifier(tenant).openSession();

However, the @Transactional annotation causes the SessionFactory to open a session with sessionFactory.getCurrentSession(), which does not pull the tenant identifier from the CurrentTenantIdentifierResolver.

Darren suggested opening the Session manually in the DAO layer, but this means that each DAO method will have a locally scoped transaction. The better place to do this is on the service layer. Each service layer call (ie, doSomeLogicalTask()) may call multiple DAO methods. It makes sense that each of these should be bound to the same transaction, as they're logically related.

Furthermore, I didn't like the idea of duplicating code in each service layer method to create and manage a transaction. Instead, I used AOP to wrap each method in my service layer with with the advice to instantiate a new Session and handle the transaction. The aspect stores the current Session in a TheadLocal stack which can be accessed by the DAO layer for querying.

All of this work will allow the interfaces and implementations to stay identical to their bug-fixed counterparts, except one line in the DAO superclass that will get the Session from the ThreadLocal stack rather than the SessionFactory. This can be changed once the bug is fixed.

I will post the code shortly, once I clean it up a little. If anybody sees any problems with this, do feel free to discuss below.