Why do I get a System.OutOfMemoryException using N

Question

Below are the details of the error:

Scenario: I'm iteration through a collection which contains a field with 'byte[]' as datatype. While iterating it is allocating byte array in lakhs. I guess this may be the suspect.

Error details:

Exception of type 'System.OutOfMemoryException' was thrown.

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: System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.

Source Error:

Line 257:                    forecast.IsFileUploaded = false;
Line 258:                    var forecastFiles = forecast.ForecastFiles.Where(x => x.IsDataValid);
Line 259:                    foreach (var forecastFile in forecastFiles)
Line 260:                    {
Line 261:                        forecastFile.IsDataValid = false;

Source File: ......

Stack Trace:

[OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.]
   System.Data.SqlTypes.SqlBinary.get_Value() +31
   System.Data.SqlClient.SqlDataReader.GetBytesInternal(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length) +1543
   System.Data.SqlClient.SqlDataReader.GetBytes(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length) +170
   NHibernate.Driver.NHybridDataReader.GetBytes(Int32 i, Int64 fieldOffset, Byte[] buffer, Int32 bufferoffset, Int32 length) +61
   NHibernate.Type.AbstractBinaryType.Get(IDataReader rs, Int32 index) +57
   NHibernate.Type.NullableType.NullSafeGet(IDataReader rs, String name) +181
   NHibernate.Type.NullableType.NullSafeGet(IDataReader rs, String[] names, ISessionImplementor session, Object owner) +56
   NHibernate.Type.AbstractType.Hydrate(IDataReader rs, String[] names, ISessionImplementor session, Object owner) +48
   NHibernate.Persister.Entity.AbstractEntityPersister.Hydrate(IDataReader rs, Object id, Object obj, ILoadable rootLoadable, String[][] suffixedPropertyColumns, Boolean allProperties, ISessionImplementor session) +1208
   NHibernate.Loader.Loader.LoadFromResultSet(IDataReader rs, Int32 i, Object obj, String instanceClass, EntityKey key, String rowIdAlias, LockMode lockMode, ILoadable rootPersister, ISessionImplementor session) +451
   NHibernate.Loader.Loader.InstanceNotYetLoaded(IDataReader dr, Int32 i, ILoadable persister, EntityKey key, LockMode lockMode, String rowIdAlias, EntityKey optionalObjectKey, Object optionalObject, IList hydratedObjects, ISessionImplementor session) +264
   NHibernate.Loader.Loader.GetRow(IDataReader rs, ILoadable[] persisters, EntityKey[] keys, Object optionalObject, EntityKey optionalObjectKey, LockMode[] lockModes, IList hydratedObjects, ISessionImplementor session) +480
   NHibernate.Loader.Loader.GetRowFromResultSet(IDataReader resultSet, ISessionImplementor session, QueryParameters queryParameters, LockMode[] lockModeArray, EntityKey optionalObjectKey, IList hydratedObjects, EntityKey[] keys, Boolean returnProxies) +409
   NHibernate.Loader.Loader.DoQuery(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +1287
   NHibernate.Loader.Loader.DoQueryAndInitializeNonLazyCollections(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +106
   NHibernate.Loader.Loader.LoadCollection(ISessionImplementor session, Object id, IType type) +331

[GenericADOException: could not initialize a collection: [ForecastingPortal.Models.ForecastDetail.ForecastFiles#bda8eb39-99df-421e-a51d-9fcd00a72e2c][SQL: SELECT forecastfi0_.ForecastDetail_id as Forecast5_1_, forecastfi0_.Id as Id1_, forecastfi0_.Id as Id116_0_, forecastfi0_.[Data] as Data2_116_0_, forecastfi0_.IsDataValid as IsDataVa3_116_0_, forecastfi0_.FileContent_id as FileCont4_116_0_ FROM [PATH_ForecastFileData] forecastfi0_ WHERE forecastfi0_.ForecastDetail_id=?]]
   NHibernate.Loader.Loader.LoadCollection(ISessionImplementor session, Object id, IType type) +494
   NHibernate.Loader.Collection.CollectionLoader.Initialize(Object id, ISessionImplementor session) +73
   NHibernate.Persister.Collection.AbstractCollectionPersister.Initialize(Object key, ISessionImplementor session) +58
   NHibernate.Event.Default.DefaultInitializeCollectionEventListener.OnInitializeCollection(InitializeCollectionEvent event) +628
   NHibernate.Impl.SessionImpl.InitializeCollection(IPersistentCollection collection, Boolean writing) +233
   NHibernate.Collection.AbstractPersistentCollection.Initialize(Boolean writing) +125
   NHibernate.Collection.AbstractPersistentCollection.Read() +31
   NHibernate.Collection.Generic.PersistentGenericBag`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() +31
   System.Linq.WhereEnumerableIterator`1.MoveNext() +72
   ForecastingPortal.ModelHelpers.InvalidateForecastDataForVaccine(VaccineDetail vaccineDetail, ISession session) in C:\Project\Path_Performance\Source\ForecastingPortal\Helpers\ModelHelpers.cs:259
   ForecastingPortal.Web.Setup.Controllers.EnvironmentElementDefinitionController.UpdateElementDetail(FormCollection form, Guid id) in C:\Project\Path_Performance\Source\ForecastingPortal.Web\Areas\Setup\Controllers\EnvironmentSetup\EnvironmentElementDefinitionController.cs:112
   lambda_method(ExecutionScope , ControllerBase , Object[] ) +220
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +178
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +24
   Autofac.Integration.Web.Mvc.ExtensibleActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +42
   System.Web.Mvc.<>c__DisplayClassd.<InvokeActionMethodWithFilters>b__a() +52
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +254
   System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +254
   System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +254
   System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +254
   System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +254
   System.Web.Mvc.<>c__DisplayClassf.<InvokeActionMethodWithFilters>b__c() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +192
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +314
   System.Web.Mvc.Controller.ExecuteCore() +105
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +39
   System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +7
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__4() +34
   System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +59
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +7
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8699438
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155