Multi-Tenancy with Spring + Hibernate: "SessionFactory configured for multi-tenancy, but no tenant identifier specified"
Are you using @Transactional
anywhere in your code (ie mark a service or dao class/method)?
I was running into the same error until I commented out the @Transactional
in my service class.
I think it's related to the default openSessionInThread behavior of Hibernate 4.
I also have hibernate configured without a custom implementation of the ConnectionProvider
and TenantIdentifierResolver
. I'm using the jndi-based approach, setting the hibernate.connection.datasource to java://comp/env/jdbc/, and then passing in the name of the jndi resource into my dao methods, which call
sessionFactory.withOptions().tenantIdentifier(tenant).openSession();
I'm still playing around to see if I can get a configuration working with @Transactional
, but the jndi-based approach with the default session in thread behavior seems to be working now.
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.
Hibernate defines the CurrentTenantIdentifierResolver
interface to help frameworks like Spring or Java EE to allow using the default Session
instantiation mechanism (be it from an EntityManagerFactory
).
So, the CurrentTenantIdentifierResolver
must be set via a configuration property which is exactly where you went wrong because you didn't supply the right fully-qualified class name. The CurrentTenantIdentifierResolver
implementation being CurrentTenantIdentifierResolverImpl
, the hibernate.tenant_identifier_resolver
has to be:
<prop key="hibernate.tenant_identifier_resolver">com.afflatus.edu.thoth.context.CurrentTenantIdentifierResolverImpl</prop>
After you fix this, when the HibernateTransactionManager
calls getSessionFactory().openSession()
, Hibernate will use the CurrentTenantIdentifierResolverImpl
to resolve the tenant identifier.