Regression in ORM 6. I think it’s specific to ORM 6.2, because I’ve never encountered this problem with ORM 6.0/6.1, but I’m not 100% sure (maybe the problem just wasn’t as visible in Hibernate Search before).

The scenario:

• Hibernate ORM boots. While building the session factory, it calls sessionFactoryCreated on all session factory observers.
• In ORM 6.2, this means in particular calling org.hibernate.boot.internal.SessionFactoryObserverForSchemaExport#sessionFactoryCreated, which successfully creates the DB schema.
• One of the next observers (say, Hibernate Search’s) throws an exception from sessionFactoryCreated (say, because the Hibernate Search mapping is invalid).
• Hibernate ORM catches that exception and attempts to close the session factory.
• Upon closing, the session factory calls sessionFactoryClosing on all session factory observers.
• In ORM 6.2, this means in particular calling org.hibernate.boot.internal.SessionFactoryObserverForSchemaExport#sessionFactoryClosing.

That last call fails with the following exception:

org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.engine.jdbc.spi.JdbcServices]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:212)
	at org.hibernate.service.internal.SessionFactoryServiceRegistryImpl.getService(SessionFactoryServiceRegistryImpl.java:100)
	at org.hibernate.tool.schema.internal.SchemaDropperImpl$DelayedDropActionImpl$JdbcContextDelayedDropImpl.<init>(SchemaDropperImpl.java:677)
	at org.hibernate.tool.schema.internal.SchemaDropperImpl$DelayedDropActionImpl.perform(SchemaDropperImpl.java:641)
	at org.hibernate.boot.internal.SessionFactoryObserverForSchemaExport.sessionFactoryClosing(SessionFactoryObserverForSchemaExport.java:48)
	at org.hibernate.internal.SessionFactoryObserverChain.sessionFactoryClosing(SessionFactoryObserverChain.java:48)
	at org.hibernate.internal.SessionFactoryImpl.close(SessionFactoryImpl.java:838)
	at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:377)

In Hibernate ORM 5, things were a bit different (e.g. schema creation/drop was not done in an observer, see https://github.com/hibernate/hibernate-search/pull/3396/commits/9b18a1ed3c096befab7243f1834428138ffd46b6 ), so it’s hard to pinpoint where the problem was introduced exactly; but I can say at least that we didn’t get that exception in Hibernate ORM 5 and the schema was properly dropped.

I believe the problem is here: https://github.com/hibernate/hibernate-orm/blob/63715770e94f18137d9d63f7d105fafa62ca687f/hibernate-core/src/main/java/org/hibernate/internal/SessionFactoryImpl.java#L460

It seems odd that we close the service registry after closing each integrator? I’d expect closing the service registry to be one of the very last things we do.