On a webAPI (C#/.Net 4) using NHibernate 4 an issue was observed under stress testing. The issue was associated with the user-impersonation being done on the database connection – the impersonation would work correctly, however, for subsequent database operations would fail. After much (and I do mean much) investigation it was found that the connections seem to be “cycled” amongst the NHibernate sessions – so we could observe the session using a connection with one particular HashCode (unique object identifier) and see the user-impersonation SQL execute, but when it came to some ORM write-backs to the DB another connection with another user’s impersonation (and differing HashCode) was observed in the session for the db operation.
Weird or what ?
I must give a round of applause to the guys at StackOverflow for this one.
Basically, create a dummy session from the session factory , then pass the connection of this session to the OpenSession method of the session factory to create the session you’re going to use.
ISession dummy = sessionFactory.Factory.OpenSession(); this.Session = sessionFactory.Factory.OpenSession(dummy.Connection);