RavenDb, Cannot access file, the file is locked or in use - asp.net-mvc-3

Question

This is exception is totally make my life a pain right now.. Don't rightly know whats changed but the database is in the App_Data folder of a MVC3 site. The website is hosted in IIS 7.5 proper as the Default Web Site.
Any tips for resolution would be welcome.
EDIT.. The problem is probably more or less related to my controller code not cleaning up after an exception is being thrown, thus not calling dispose on the document session
Line 30: instance = new EmbeddableDocumentStore { ConnectionStringName = "RavenDB" };
Line 31: instance.Conventions.IdentityPartsSeparator = "-";
Line 32: instance.Initialize();
[EsentFileAccessDeniedException: Cannot access file, the file is locked or in use]
Microsoft.Isam.Esent.Interop.Api.Check(Int32 err) in C:\Work\ravendb\SharedLibs\Sources\managedesent-61618\EsentInterop\Api.cs:2739
Microsoft.Isam.Esent.Interop.Api.JetInit(JET_INSTANCE& instance) in C:\Work\ravendb\SharedLibs\Sources\managedesent-61618\EsentInterop\Api.cs:131
Raven.Storage.Esent.TransactionalStorage.Initialize(IUuidGenerator uuidGenerator) in c:\Builds\RavenDB-Stable\Raven.Storage.Esent\TransactionalStorage.cs:207
[InvalidOperationException: Could not open transactional storage: C:\code\BE\Com.BuyEfficient\Com.BuyEfficient.Web\App_Data\ravendata\Data]
Raven.Storage.Esent.TransactionalStorage.Initialize(IUuidGenerator uuidGenerator) in c:\Builds\RavenDB-Stable\Raven.Storage.Esent\TransactionalStorage.cs:220
Raven.Database.DocumentDatabase..ctor(InMemoryRavenConfiguration configuration) in c:\Builds\RavenDB-Stable\Raven.Database\DocumentDatabase.cs:156
Raven.Client.Embedded.EmbeddableDocumentStore.InitializeInternal() in c:\Builds\RavenDB-Stable\Raven.Client.Embedded\EmbeddableDocumentStore.cs:143
Raven.Client.Document.DocumentStore.Initialize() in c:\Builds\RavenDB-Stable\Raven.Client.Lightweight\Document\DocumentStore.cs:483
Com.BuyEfficient.Web.Infrastructure.DataDocumentStore.Initialize() in C:\code\BE\Com.BuyEfficient\Com.BuyEfficient.Web\Infrastructure\DataDocumentStore.cs:32
Com.BuyEfficient.Web.App_Start.Services.PreStart() in C:\code\BE\Com.BuyEfficient\Com.BuyEfficient.Web\App_Start\Services.cs:25
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner) +0
System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner) +72
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +335
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +28
System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) +19
WebActivator.BaseActivationMethodAttribute.InvokeMethod() +221
WebActivator.ActivationManager.RunActivationMethods() +491
WebActivator.ActivationManager.RunPreStartMethods() +28
WebActivator.ActivationManager.Run() +55
[InvalidOperationException: The pre-application start initialization method Run on type WebActivator.ActivationManager threw an exception with the following error message: Exception has been thrown by the target of an invocation..]
System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +423
System.Web.Compilation.BuildManager.CallPreStartInitMethods() +306
System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +677
[HttpException (0x80004005): The pre-application start initialization method Run on type WebActivator.ActivationManager threw an exception with the following error message: Exception has been thrown by the target of an invocation..]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9090044
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +97
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +256

Answer 1

Spaten, you need to make sure that you handle DocumentStore and DocumentSession lifecycle management properly. You should create the DocumentStore as a singleton on application start and you should open and dispose session on begin and end request. I suggest writing your own handlers for OnBeginRequest and OnEndRequest.
Please take a look at the official sample application, RaccoonBlog, to see how this works.