I need to use both MySQL and MongoDB in my project. MySQL for structured data and MongoDB for unstructured.

I see that if I import the ogm classes for MongoDB, then MySQL sessionfactory creation has the below trace.

Feb 21, 2014 11:53:52 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000046: Connection properties: {user=root, password=****}
Feb 21, 2014 11:53:53 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Feb 21, 2014 11:53:53 AM org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
Feb 21, 2014 11:53:53 AM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
Feb 21, 2014 11:53:53 AM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
Exception in thread "main" java.lang.StackOverflowError
at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:988)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.locateServiceBinding(AbstractServiceRegistryImpl.java:114)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.locateServiceBinding(AbstractServiceRegistryImpl.java:109)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:124)
at org.hibernate.ogm.service.impl.OptionalServiceInitiator.initiateService(OptionalServiceInitiator.java:36)
at org.hibernate.ogm.service.impl.OptionalServiceInitiator.initiateService(OptionalServiceInitiator.java:41)
at org.hibernate.ogm.service.impl.OptionalServiceInitiator.initiateService(OptionalServiceInitiator.java:41)
at org.hibernate.ogm.service.impl.OptionalServiceInitiator.initiateService(OptionalServiceInitiator.java:41)
at org.hibernate.ogm.service.impl.OptionalServiceInitiator.initiateService(OptionalServiceInitiator.java:41)

It seems that MySQL sessionfactory creation is using OGM classes. I'm able to create MySQL and MongoDB sessions separately (so the code is working if I comment out either one of MySQL or MongoDB related code).

Below is my code -

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.Session;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.ogm.cfg.OgmConfiguration;

public class Platform {

private static final SessionFactory mySQLSessionFactory = buildMySQLSessionFactory();
private static final SessionFactory mongoSessionFactory = buildMongoSessionFactory();


private static SessionFactory buildMySQLSessionFactory() {
Configuration configuration = new Configuration();
configuration.configure("mysql.cfg.xml");
ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
org.hibernate.SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
return sessionFactory;
}

private static SessionFactory buildMongoSessionFactory() {
OgmConfiguration configuration=new OgmConfiguration();
configuration.configure("mongdb.cfg.xml");
ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
org.hibernate.ogm.SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
return sessionFactory;
}

public static void shutdown() {
mySQLSessionFactory.close();
mongoSessionFactory.close();
}

public static void main( String[] args )
{
Session mysqlSession = mySQLSessionFactory.openSession();
Session mongoSession = mongoSessionFactory.openSession();
}
}

Is there a way to isolate these session creations so that they do not interfere? Any other suggestions?

Thanks!
-Ashish

I made a mistake in posting the code. I was experimenting to see if there is a org.hibernate.ogm.SessionFactory to isolate these two factories, and by mistake I posted that in the code. The actual buildMongoSessionFactory is -

private static SessionFactory buildMongoSessionFactory() {
OgmConfiguration configuration=new OgmConfiguration();
configuration.configure("mongdb.cfg.xml");
ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
return sessionFactory;
}

Sorry for the confusion.

Hi Ashish,

Could you try the latest release (4.1.0.Beta1, see [1]) and check whether you still get the problem then? I believe you're running into OGM-416 [2] which was fixed in 4.1 Beta1.

Thanks,

--Gunnar

[1] http://in.relation.to/Bloggers/HibernateOGM410Beta1IsOut
[2] https://hibernate.atlassian.net/browse/OGM-416