Why will NHibernate not use 2nd level cache on second request?

Question

I have the following model.

<class name="Navigation" table="`navigation`">
    <cache usage="nonstrict-read-write" region="LongTerm" />

    <id name="Id" column="`navigation_id`" type="Int16" unsaved-value="0">
        <generator class="native" />
    </id>

    <property name="Name" column="`navigation_name`" type="String" not-null="true" />
    <property name="DateCreated" column="`navigation_date-created`" type="DateTime" not-null="true" />
    <property name="DateSaved" column="`navigation_date-saved`" type="DateTime" not-null="true" />
    <property name="Active" column="`navigation_active`" type="Boolean" not-null="true" />
    <property name="RestrictToWebMaster" column="`navigation_web-master-restrict`" type="Boolean" not-null="true" />

    <many-to-one name="User" column="user_id" class="User" />

    <set name="Items" order-by="`navigation-item_index` asc" inverse="true" cascade="all-delete-orphan">
        <cache usage="nonstrict-read-write" region="LongTerm" />

        <key column="`navigation_id`" />
        <one-to-many class="Navigation+Item" />
    </set>
</class>

Then I have a test.aspx that querys a collection.

DataProvider provider = new DataProvider(SessionManager.GetSession());

protected void Page_Load(object sender, EventArgs e)
{
    IList<Navigation> navs = provider.Session.QueryOver<Navigation>()
        .Cacheable()
        .List();

    foreach (Navigation nav in navs) {
        litTest.Text += nav.Name + "<br />";
    }
}

When, I reload the page the query is re-run. Why isn't the data retrieved from cache?

<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2-x-factories">
    <session-factory name="Default">
        <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
        <property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property>
        <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>

        <property name="current_session_context_class">web</property>
        <property name="show_sql">true</property>

        <property name="cache.provider_class">NHibernate.Caches.SysCache.SysCacheProvider, NHibernate.Caches.SysCache</property>
        <property name="cache.use_query_cache">true</property>
        <property name="cache.use_second_level_cache">true</property>
    </session-factory>
</hibernate-configuration>

<syscache>
    <cache region="LongTerm" expiration="3600" priority="5" />
    <cache region="MediumTerm" expiration="900" priority="3" />
    <cache region="ShortTerm" expiration="180" priority="1" />
</syscache>

Answer 1

You should run this in a transaction and commit the transaction at the end.

NHibernate updates the 2nd level cache only if the transaction has been committed successfully. If you don't start a NHibernate transaction, NHibernate will not know if the results are good enough to be cached.