alt NuGet

NHibernate is a widely used ORM and it is supported by MassTransit for saga storage. The example below shows the code-first approach to using NHibernate for saga persistence.

public class OrderState :    SagaStateMachineInstance{    public Guid CorrelationId { get; set; }    public string CurrentState { get; set; }    public DateTime? OrderDate { get; set; }    // If using Optimistic concurrency, this property is required    public int Version { get; set; }}

The instance properties are configured using a SagaClassMapping.

The SagaClassMapping has a default mapping for the CorrelationId as the primary key. If you create your own mapping, you must follow the same convention, or at least make it a Clustered Index + Unique, otherwise you will likely experience deadlock exceptions and/or performance issues in high throughput scenarios.
public class OrderStateMap :     SagaClassMapping<OrderState>{    public OrderStateMap()    {        Property(x => x.CurrentState, x => x.Length(64));        Property(x => x.OrderDate);        Property(x => x.Version); // If using Optimistic concurrency    }}


To configure NHibernate as the saga repository for a saga, use the code shown below using the AddMassTransit container extension. This will configure NHibernate to connect to the local NHibernate instance on the default port using Optimistic concurrency.

// the session factory should be registered as a single instancecontainer.RegisterSingleInstance<ISessionFactory>(...);container.AddMassTransit(cfg =>{    cfg.AddSagaStateMachine<OrderStateMachine, OrderState>()        .NHibernateRepository();});


NHibernate natively supports multiple concurrency handling mechanisms. The easiest is probably adding a Version property of type int to the saga instance class and map it to the column with the same name

Table of Contents