Hi, While reviewing this PR: https://github.com/hibernate/hibernate-orm/pull/1198/files I realized that we have some static fields which might cause some problems when we deploy two or more SessionFactories in the same container (e.g. Spring). The fix suggests that we should use synchronised, as indicated by Sonar, but I think we should avoid the static fields altogether. Every instance variable must be confined to an object that's confined to the same SessionFactory root object. Without static fields, we can make sure that nothing escapes a given SessionFactory. Let me know what you think. Vlad