Hey, I just realized that when my web app is just starting, and two requests hit the server at about the same time, NHibernate chokes with the below error. Can anyone tell me what's going wrong, and/or what other info I should provide?


Server Error in '/Web' Application.
duplicate cache region
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: NHibernate.MappingException: duplicate cache region

Source Error:

Line 31: {
Line 32: if (factory == null)
Line 33: factory = Config.BuildSessionFactory();
Line 34: return factory;
Line 35: }


Source File: C:\wc\RDAS\MyNHibernateContrib\DbMgr.cs Line: 33

Stack Trace:

[MappingException: duplicate cache region]
NHibernate.Cfg.Binder.BindCollectionSecondPass(XmlNode node, Collection model, IDictionary persistentClasses, Mappings mappings) +1584
NHibernate.Cfg.Binder.BindMapSecondPass(XmlNode node, Map model, IDictionary classes, Mappings mappings) +37
NHibernate.Cfg.MapSecondPass.secondPass(IDictionary persistentClasses) +56
NHibernate.Cfg.SecondPass.DoSecondPass(IDictionary persistentClasses) +66
NHibernate.Cfg.Configuration.SecondPassCompile() +131
NHibernate.Cfg.Configuration.BuildSessionFactory() +12
MyNHibernateContrib.DbMgr.get_Factory() in C:\wc\RDAS\MyNHibernateContrib\DbMgr.cs:33
MyNHibernateContrib.DbMgr.BeginSession() in C:\wc\RDAS\MyNHibernateContrib\DbMgr.cs:67
Global.Application_BeginRequest(Object sender, EventArgs e) in c:\wc\RDAS\Web\App_Code\Global.asax.cs:78
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +65


Version Information: Microsoft .NET Framework Version:2.0.50215.44; ASP.NET Version:2.0.50215.44

You might have some duplication in your configuration. What does your config look like?

Are you creating the session factory simultaneously from two threads? You probably should use some synchronization in the code you showed above.

I think I was lacking the synchronization code around the creation of the session factory. I added the code, and since then have been unable to reproduce the error.

Thank you! (I should have figured that out myself)