Question

I am having a problem where a criteria query in NHibernate is executes in less then a second when I run it in a unit test, but when I try to run it from the context of my web application, it takes over a minute. Both are hitting the same database for the same data.

My NHibernate mapping:

var properties = new Dictionary<string, string>();
var configuration = new Configuration();

properties.Add("connection.provider", "NHibernate.Connection.DriverConnectionProvider");
properties.Add("proxyfactory.factory_class", "NHibernate.Bytecode.DefaultProxyFactoryFactory, NHibernate");
properties.Add("connection.release_mode", "on_close");
properties.Add("current_session_context_class", "web");
properties.Add("dialect", "NHibernate.Dialect.MsSql2005Dialect");
properties.Add("connection.connection_string_name", "DBConnection");
configuration.Properties = properties;
SessionFactory = configuration.BuildSessionFactory();

The only difference in this mapping between tests and the web app is the current_session_context_class, where it is thread_static in tests, but that does not seem to be the problem.

The criteria for the query:

var reports =   Session.CreateCriteria<Report>()
        .SetFetchMode("Site", FetchMode.Join)
        .SetFetchMode("Actions", FetchMode.Join)
        .SetResultTransformer(new DistinctRootEntityResultTransformer())
        .Add(Subqueries.PropertyIn("Site",
            SiteCriteria.GetSitesForUserWithPermission(user, Permission.SomePermission))))
        .List<Report>();

I have tried using NH Profiler to help, but it did not offer any useful suggestions.

edit: Looking further in nhprofiler, I see that in the test for example, the query duration is 1ms / 313ms (Database only / Total).
But for the website it just took me 1ms / 43698ms. It seems that NHibernate is having a hard time mapping the actual objects.

Answer 1

The difference between the unit tests and the web app is that unit tests aren’t logged.
I added to our log4net.config:

<filter type="log4net.Filter.LevelRangeFilter">
    <levelMin value="WARN" />
</filter>

And the problem went away.

It was outputting a lot of stuff like this:

2011-07-21 13:07:17,479 DEBUG [14] LoadContexts - attempting to locate loading collection entry [CollectionKey[Actions#d6adfe87-a7d4-4821-bb10-4ef76fcf614d]] in any result-set context
2011-07-21 13:07:17,481 DEBUG [14] LoadContexts - collection [CollectionKey[Actions#d6adfe87-a7d4-4821-bb10-4ef76fcf614d]] not located in load context