Question

In my ASP.NET webforms app, I am getting the above exception predominately, along with:
– A collection with cascade=”all-delete-orphan” was no longer referenced by the owning entity instance: Persistence.Product.ModelMap
– collection was processed twice by flush()
– Found shared references to a collection: Persistence.Product.ModelMap
when I am retrieving products. It happens only when I have two or more requests hit the server at once. I am using one session per request.

The property, ModelMap, is defined as follows in the Hibernate XML in the Products mapping definition:

<bag name="ModelMap" table="MapProductModel" cascade="all-delete-orphan" lazy="true" inverse="true" where="IsDeleted=0">
  <key column="fkProductId" />
  <one-to-many class="MapProductModel" />
</bag>

This happens on the following line of code

IList<T> itemList = criteria.List<T>();

When the retrieving the product.

Any help greatly appreciated, Google didn’t really turn up anything.

Answer 1

ASP.NET is multithreaded, so requests will come in on multiple threads in the same HTTP request. You should be using NHibernate’s web session context (or other means); creating a new session per HTTP request is not enough. See http://nhibernate.info/doc/nhibernate-reference/architecture.html#architecture-current-session