Masstransit Saga redelivery

Question

I would like to setup message scheduling redelivering for state machine saga using standalone quartz scheduler. Now It works fine with plain consumer, but I can't setup redelivering for saga properly. My saga configuration looks like this :

MassTransit.Bus.Factory.CreateUsingRabbitMq(cfg =>
        {
            var retryPolicy = Retry.Incremental(5, TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(2));

            cfg.UseMessageScheduler(new Uri($"rabbitmq://localhost/SchedulerQueue"));

            var host = cfg.Host(new Uri(uri), h =>
            {
                h.Username(config.RabbitMqUser);
                h.Password(config.RabbitMqPassword);
            });

            cfg.ReceiveEndpoint(host, "SagaQueue", e =>
            {
                e.Durable = true;

                e.StateMachineSaga(new MySaga(),
                    repository, c =>
                    {
                        c.UseTransaction();
                        c.Message<ISagaEvent>(y => y.UseScheduledRedelivery(retryPolicy));
                    });
            });
        });

where ISagaEvent is message processed by saga. Am I doing something wrong, and is there a way to configure scheduled redelivery for saga at all?

Answer 1

To schedule within a saga, it's typically best to use the actual state machine schedule feature, so the state of the saga is updated to indicate redelivery.

Essentially, if you receive an event in a state that is not yet ready for it, use the Schedule() to schedule the message for some time in the future when the saga may be in a state where it can be processed.

A good schedule example is in the documentation: http://masstransit-project.com/MassTransit/advanced/sagas/automatonymous.html