Entity Framework 5 Cyclic Lazy Loading Cause OutOfMemoryException - lazy-loading

Question

I have problem with EF 5 and Lazy loading with cyclic references.
The below picture represents my model.
The main problem is between Model and ModelProperties classes, because Model contains IEnumerable navigation property and ModelProperty contains Model navigation property.
So this design cause the situation below
You can access fullsize image http://tinypic.com/r/2vskuxl/6
As you can imagine this cause very big problem, OutOfMemory exception.
Only solution that i could find is disabling lazy loading and using other methods. But lazy loading is very simplifying our work.
I hope there is a configuration or an attribute to help me loading only two levels of relations with lazy loading.
Is there any way to achieve this?
UPDATE:
Regarding the request from Julie Lerman, here is the visual model of EF.
I highlighted the main relation that cause problem.
Also you can access full-size at http://tinypic.com/r/30v15pg/6
UPDATE 2:
Here is the model definitions.
public class Model {
public int ModelID { get; set; }
public int BrandID {
get;
set;
}
public virtual Brand Brand { get; set; }
public string Logo { get; set; }
public string Name { get; set; }
public virtual ICollection<ModelProperty> ModelProperties {
get;
set;
}
}
public class ModelProperty {
public int ModelPropertyID {
get;
set;
}
public virtual int PropertyDefinitionID {
get;
set;
}
public virtual PropertyDefinition PropertyDefinition {
get;
set;
}
public virtual int ModelID {
get;
set;
}
public virtual Model Model {
get;
set;
}
public bool IsContainable {
get;
set;
}
public bool HasFilterDefinition {
get;
set;
}
public virtual ICollection<ModelPropertyValue> ModelPropertyValues {
get;
set;
}
public virtual ICollection<ModelPropertyMatchingFilter> ModelPropertyMatchingFilter {
get;
set;
}
}
Also there is an entity configuration for ModelProperty.
public class ModelPropertyEntityTypeConfiguration : EntityTypeConfiguration<ModelProperty> {
public ModelPropertyEntityTypeConfiguration() {
HasKey(p => p.ModelPropertyID);
HasRequired(p => p.PropertyDefinition).WithMany(s => s.ModelProperties).HasForeignKey(s => s.PropertyDefinitionID).WillCascadeOnDelete(false);
HasRequired(p => p.Model).WithMany(s => s.ModelProperties).HasForeignKey(s => s.ModelID).WillCascadeOnDelete(false);
HasMany(p => p.ModelPropertyValues).WithRequired(s => s.ModelProperty).HasForeignKey(s => s.ModelPropertyID).WillCascadeOnDelete(true);
HasMany(p => p.ModelPropertyMatchingFilter).WithRequired(s => s.ContainerModelProperty).HasForeignKey(s => s.ContainerModelPropertyID).WillCascadeOnDelete(false);
ToTable("dbo.ModelProperties");
}
}
UPDATE 3:
I am not sure but Automapper can cause this also. Because Entity Framework Profile tells thousands of Autommaper methods called while running.
UPDATE 4:
Here is the EFProf stacktrace:
You access bigger version http://tinypic.com/r/21cazv4/6
UPDATE 5
You can see sample project here: https://github.com/bahadirarslan/AutomapperCircularReference
In sample, you can see easily endless loops via Quick watch.

Answer 1

Thanks for the update. You're model looks fine. It definitely knows this is just a 1:* relationship. Ladislav (as usual) is correct. LL doesn't cause the problem...except in ONE place which is during serialization. Is there a chance that you have your code in a service? With regular lazy loading, only the property you explicitly mention will get lazy loaded. But during serialization, the serialization "mentions" every property so it just keeps loading and loading properties throughout the graph AND causes circular dependency issues. With services we have to turn lazy loading off (using context.configuration.lazyloadingenabled=false) before you return the data. So in the service method, you can eager load, or lazy load or explicitly load to get your graph but then disable lazy loading before you return the results.

Answer 2

you should disable lazy loading in order to bypass proxy objects or you should return what you need as a DTO. using DTO is preferred because of hiding details of your domain