Multi tenancy with schema per tenant

Question

Hello,
I am tryign to run multi tenancy with schema per tenant. It seems to work good when tenant ID is set in XML as a property for persistance unit.
But I need to set tenant in code. Is that possible? How?
I found this article:
codecrafters.blogspot.it/2013/03/multi-tenant-cloud-applications-with.html
So I tried to set it in doBegin method in custom transaction manager. But that doesn't work. I guess relation descriptors aren't updated right.
I could provide more info with exception stack also but first... have I pick the right approach?
Thanks!
Martin

Answer 1

UPDATE 26.6.2015: This isn't completelly right solution. Read also comments below or go to my article at http://www.mafospace.com/articles/multi-tenancy-with-eclipselink-and-inherited-entities
I've solved it finally. Maybe it will be helpful for someone. I've done that in similar way as described in article I linked in first post. Through custom transaction manager.
import org.eclipse.persistence.config.PersistenceUnitProperties;
import org.eclipse.persistence.internal.jpa.EntityManagerImpl;
import org.eclipse.persistence.sessions.coordination.MetadataRefreshListener;
import org.eclipse.persistence.sessions.server.ServerSession;
import org.springframework.orm.jpa.JpaTransactionManager;
import sk.bantip.hotel.server.security.SecurityHelper;
import javax.persistence.EntityManager;
import java.util.HashMap;
import java.util.Map;
public class MultiTenantJpaTransactionManager extends JpaTransactionManager {
* NOTE:
* Maybe it would be also possible to replace existing entityManager in transaction with new but it
* isn't a good idea because of rollback and other problems.
* So when new tenant is required always start new transaction for it.
@Override
protected javax.persistence.EntityManager createEntityManagerForTransaction() {
EntityManager em = super.createEntityManagerForTransaction();
boolean refreshed = false;
String actualTenant = null;
ServerSession ss = ((EntityManagerImpl) em.getDelegate()).getServerSession();
Map sessionProp = ss.getProperties();
actualTenant = (String) sessionProp.get(PersistenceUnitProperties.MULTITENANT_PROPERTY_DEFAULT);
// don't run it if tenant didn't change
// it should be quite faster then
if ((actualTenant == null && SecurityHelper.getActiveTenantSchema() != null) ||
(actualTenant != null && !actualTenant.equals(SecurityHelper.getActiveTenantSchema()))) {
// set new tenant as property for actual session
// while refreshing metadata it will be used from actual session for new session
sessionProp.put(PersistenceUnitProperties.MULTITENANT_PROPERTY_DEFAULT, SecurityHelper.getActiveTenantSchema());
MetadataRefreshListener mrl = ((EntityManagerImpl) em.getDelegate()).getServerSession().getRefreshMetadataListener();
// metadata refresh listener is empty if it was already run for actual transaction (same entity manager)
// because it is placed in createEntityManagerForTransaction now this shouldn't happen but to be sure...
if (mrl != null) {
Map<String, Object> prop = new HashMap<String, Object>();
// metadata will be refreshed for next created entity manager
mrl.triggerMetadataRefresh(prop);
refreshed = true;
// if metadata for "old" entity manager wasn't refreshed we don't need to create a new one
return refreshed ? super.createEntityManagerForTransaction() : em;
Everything seems to work except inheritance with strategy type JOINED now. To fix that use customizer.
import org.eclipse.persistence.annotations.TenantTableDiscriminatorType;
import org.eclipse.persistence.config.DescriptorCustomizer;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.descriptors.TablePerMultitenantPolicy;
* For some reason when using table per tenant with schema discriminator isn't set good for child
* entities with inheritance JOINED strategy. It stay as SUFFIX and therefore it doesn't work.
public class InheritanceJoinedMTFixCustomizer implements DescriptorCustomizer {
@Override
public void customize(ClassDescriptor descriptor) throws Exception {
// set discriminator to SCHEMA
((TablePerMultitenantPolicy) descriptor.getMultitenantPolicy())
.setTenantTableDiscriminatorType(TenantTableDiscriminatorType.SCHEMA);
And in child entities use it like this:
@Customizer(InheritanceJoinedMTFixCustomizer.class)
public class Person extends Contact {