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我们使用带有自动匿名和 InMemoryRepository 的 Masstransit 来实现 saga 持久性。我们配置了大约 3 个状态机并且运行良好。我们最近从 InMemoryRepository 更改为 EFCore 以实现持久性。这导致只有第一个配置的状态机可以完美运行。休息所有状态机甚至没有进入 Initially 事件。需要帮助来了解实施是否正确。以下是代码详细信息：

大众运输状态机设置

 services.AddMassTransit(x =>
        {
            x.AddBus(provider => MassTransit.Bus.Factory.CreateUsingRabbitMq(cfg =>
            {
                cfg.Host(hostUri, hst =>
                {
                    hst.Username(appSettings.RabbitMQ.Username);
                    hst.Password(appSettings.RabbitMQ.Password);
                });

                cfg.ReceiveEndpoint("microservice-response", e =>
                {
                    AddConsumers(e, provider);
                    e.ConfigureSaga<ServiceRequest1RegisterState>(provider);
                    e.ConfigureSaga<ServiceRequest1UpdateState>(provider);
                    e.ConfigureSaga<ServiceRequest1ApproveState>(provider);
                });
            }));

            ////x.AddSagaStateMachine<ServiceRequest1RegisterStateMachine, ServiceRequest1RegisterState>()
            ////   .InMemoryRepository();
            ////x.AddSagaStateMachine<ServiceRequest1UpdateStateMachine, ServiceRequest1UpdateState>()
            ////   .InMemoryRepository();
            ////x.AddSagaStateMachine<ServiceRequest1ApproveStateMachine, ServiceRequest1ApproveState>()
            ////   .InMemoryRepository();

            x.AddSagaStateMachine<ServiceRequest1RegisterStateMachine, ServiceRequest1RegisterState>()
                .EntityFrameworkRepository(r =>
                {
                    r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                    r.AddDbContext<DbContext, ServiceRequest1RegisterStateDbContext>((provider, builder) =>
                    {
                        builder.UseSqlServer(configuration.GetConnectionString("StateDBConnection"), m =>
                        {
                            m.MigrationsAssembly(Assembly.GetExecutingAssembly().GetName().Name);
                            m.MigrationsHistoryTable($"__{nameof(ServiceRequest1RegisterStateDbContext)}");
                        });
                    });
                });

    x.AddSagaStateMachine<ServiceRequest1UpdateStateMachine, ServiceRequest1UpdateState>()
                .EntityFrameworkRepository(r =>
                {
                    r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                    r.AddDbContext<DbContext, ServiceRequest1UpdateStateDbContext>((provider, builder) =>
                    {
                        builder.UseSqlServer(configuration.GetConnectionString("StateDBConnection"), m =>
                        {
                            m.MigrationsAssembly(Assembly.GetExecutingAssembly().GetName().Name);
                            m.MigrationsHistoryTable($"__{nameof(ServiceRequest1UpdateStateDbContext)}");
                        });
                    });
                });

            x.AddSagaStateMachine<ServiceRequest1ApproveStateMachine, ServiceRequest1ApproveState>()
                .EntityFrameworkRepository(r =>
                {
                    r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                    r.AddDbContext<DbContext, ServiceRequest1ApproveStateDbContext>((provider, builder) =>
                    {
                        builder.UseSqlServer(configuration.GetConnectionString("StateDBConnection"), m =>
                        {
                            m.MigrationsAssembly(Assembly.GetExecutingAssembly().GetName().Name);
                            m.MigrationsHistoryTable($"__{nameof(ServiceRequest1ApproveStateDbContext)}");
                        });
                    });
                });
        });

        services.AddSingleton<IHostedService, MassTransitBusService>();

所有 3 个状态机的 DBContext 如下所示

 public class ServiceRequest1ApproveStateDbContext : SagaDbContext
{
    public ServiceRequest1ApproveStateDbContext(DbContextOptions<ServiceRequest1ApproveStateDbContext> options)
        : base(options)
    {
    }

    /// <summary>
    /// Gets the configurations.
    /// </summary>
    protected override IEnumerable<ISagaClassMap> Configurations
    {
        get { yield return new ServiceRequest1ApproveStateMap(); }
    }
}

下面的状态图

public class ServiceRequest1ApproveStateMap : SagaClassMap<ServiceRequest1ApproveState>
{
    protected override void Configure(EntityTypeBuilder<ServiceRequest1ApproveState> entity, ModelBuilder model)
    {
        entity.Property(x => x.CurrentState).HasMaxLength(64);
        entity.Property(x => x.Id);
        entity.Property(x => x.ServiceId);
        entity.Property(x => x.ReadyEventStatus);
    }
}

从上面的代码中，只有 ServiceRequest1RegisterStateMachine 可以正常工作，其余的状态机甚至都没有进入 Initially。我可以确认迁移都是事先完成的，并且当仅存在 1 个存储库配置时，这些状态机都可以单独正常工作，即，如果只有 ServiceRequest1ApproveStateMachine 的 repo 配置，则此状态机可以正常工作。但是如果所有 3 个 repo 配置都存在，那么只有第一个有效。我需要有关使用 EFCore 正确实现 saga 持久性的指导。我是否应该尝试使用 masstransit 文档中提到的单个 dbcontext 来实现（https://masstransit-project.com/usage/sagas/efcore.html）

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1 回答 1

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下面是我为确保状态机按预期工作所做的更改。尽管我们最初的状态机实现是基于 sqlserver efcore persistence 上的文档，但这些更改是根据评论中的 @Chris 建议完成的。

services.AddDbContext<ServiceRequest1RegisterStateDbContext>(x =>
                     x.UseSqlServer(configuration.GetConnectionString("StateDBConnection")));
        services.AddDbContext<ServiceRequest1UpdateStateDbContext>(x =>
                       x.UseSqlServer(configuration.GetConnectionString("StateDBConnection")));
        services.AddDbContext<ServiceRequest1ApproveStateDbContext>(x =>
                        x.UseSqlServer(configuration.GetConnectionString("StateDBConnection")));

services.AddMassTransit(x =>
    {
        x.AddBus(provider => MassTransit.Bus.Factory.CreateUsingRabbitMq(cfg =>
        {
            cfg.Host(hostUri, hst =>
            {
                hst.Username(appSettings.RabbitMQ.Username);
                hst.Password(appSettings.RabbitMQ.Password);
            });

            cfg.ReceiveEndpoint("microservice-response", e =>
            {
                AddConsumers(e, provider);
                e.ConfigureSaga<ServiceRequest1RegisterState>(provider);
                e.ConfigureSaga<ServiceRequest1UpdateState>(provider);
                e.ConfigureSaga<ServiceRequest1ApproveState>(provider);
            });
        }));

        ////x.AddSagaStateMachine<ServiceRequest1RegisterStateMachine, ServiceRequest1RegisterState>()
        ////   .InMemoryRepository();
        ////x.AddSagaStateMachine<ServiceRequest1UpdateStateMachine, ServiceRequest1UpdateState>()
        ////   .InMemoryRepository();
        ////x.AddSagaStateMachine<ServiceRequest1ApproveStateMachine, ServiceRequest1ApproveState>()
        ////   .InMemoryRepository();

        x.AddSagaStateMachine<ServiceRequest1RegisterStateMachine, ServiceRequest1RegisterState>()
            .EntityFrameworkRepository(r =>
            {
                r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                r.ExistingDbContext<ServiceRequest1RegisterStateDbContext>();
            });

x.AddSagaStateMachine<ServiceRequest1UpdateStateMachine, ServiceRequest1UpdateState>()
            .EntityFrameworkRepository(r =>
            {
                r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                r.ExistingDbContext<ServiceRequest1UpdateStateDbContext>();
            });

        x.AddSagaStateMachine<ServiceRequest1ApproveStateMachine, ServiceRequest1ApproveState>()
            .EntityFrameworkRepository(r =>
            {
                r.ConcurrencyMode = ConcurrencyMode.Pessimistic; // or use Optimistic, which requires RowVersion

                r.ExistingDbContext<ServiceRequest1ApproveStateDbContext>();
            });
    });

    services.AddSingleton<IHostedService, MassTransitBusService>();

}

于 2020-11-06T08:54:27.860 回答