EntityFramework DbContext lifecycle + Postgres: "一个操作正在

这几天我一直在摆弄下面的东西。

我有一个南希应用程序运行在Mono上，与实体框架与存储库模式和UnitOfWork，和Postgres。Nancy使用TinyIoC作为它的IoC容器

我有一个web应用程序，队列请求在前端，所以后端得到命中一个请求的时间。

然而，当我运行一个连接到同一个后端并且不将请求排队到后端时，问题就开始了，有时几乎同时触发请求。

后端开始随机抛出以下错误:

2016-09-20T13:30:16.120057436Z app[web.1]: System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details. ---> System.InvalidOperationException: An operation is already in progress.
2016-09-20T13:30:16.120104535Z app[web.1]:   at Npgsql.NpgsqlConnector.StartUserAction (ConnectorState newState) <0x41ad0150 + 0x00313> in <filename unknown>:0
2016-09-20T13:30:16.120113254Z app[web.1]:   at Npgsql.NpgsqlCommand.ExecuteDbDataReaderInternal (CommandBehavior behavior) <0x41acfe30 + 0x0002f> in <filename unknown>:0
2016-09-20T13:30:16.120119308Z app[web.1]:   at Npgsql.NpgsqlCommand.ExecuteDbDataReader (CommandBehavior behavior) <0x41acfe00 + 0x00013> in <filename unknown>:0
2016-09-20T13:30:16.120125313Z app[web.1]:   at System.Data.Common.DbCommand.ExecuteReader (CommandBehavior behavior) <0x41f1a3c0 + 0x00018> in <filename unknown>:0
2016-09-20T13:30:16.120131185Z app[web.1]:   at (wrapper remoting-invoke-with-check) System.Data.Common.DbCommand:ExecuteReader (System.Data.CommandBehavior)
2016-09-20T13:30:16.120206045Z app[web.1]:   at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<Reader>b__c (System.Data.Common.DbCommand t, System.Data.Entity.Infrastructure.Interception.DbCommandInterceptionContext`1 c) <0x41f1ac20 + 0x00027> in <filename unknown>:0
2016-09-20T13:30:16.120220450Z app[web.1]:   at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1[TInterceptor].Dispatch[TTarget,TInterceptionContext,TResult] (System.Data.Entity.Infrastructure.Interception.TTarget target, System.Func`3 operation, System.Data.Entity.Infrastructure.Interception.TInterceptionContext interceptionContext, System.Action`3 executing, System.Action`3 executed) <0x41b1d3c0 + 0x0010e> in <filename unknown>:0
2016-09-20T13:30:16.120232740Z app[web.1]:   at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader (System.Data.Common.DbCommand command, System.Data.Entity.Infrastructure.Interception.DbCommandInterceptionContext interceptionContext) <0x41f1a880 + 0x00263> in <filename unknown>:0
2016-09-20T13:30:16.120267802Z app[web.1]:   at System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader (CommandBehavior behavior) <0x41f1a3f0 + 0x000e6> in <filename unknown>:0
2016-09-20T13:30:16.120274613Z app[web.1]:   at System.Data.Common.DbCommand.ExecuteReader (CommandBehavior behavior) <0x41f1a3c0 + 0x00018> in <filename unknown>:0
2016-09-20T13:30:16.120318116Z app[web.1]:   at (wrapper remoting-invoke-with-check) System.Data.Common.DbCommand:ExecuteReader (System.Data.CommandBehavior)
2016-09-20T13:30:16.120326788Z app[web.1]:   at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands (System.Data.Entity.Core.EntityClient.EntityCommand entityCommand, CommandBehavior behavior) <0x41f154c0 + 0x00043> in <filename unknown>:0
2016-09-20T13:30:16.120332587Z app[web.1]:   --- End of inner exception stack trace ---
2016-09-20T13:30:16.120336995Z app[web.1]:   at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands (System.Data.Entity.Core.EntityClient.EntityCommand entityCommand, CommandBehavior behavior) <0x41f154c0 + 0x000b3> in <filename unknown>:0
2016-09-20T13:30:16.120344218Z app[web.1]:   at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType] (System.Data.Entity.Core.Objects.ObjectContext context, System.Data.Entity.Core.Objects.ObjectParameterCollection parameterValues) <0x41f11e50 + 0x000a4> in <filename unknown>:0

我正在注册的依赖，喜欢，在南希引导程序:

protected override void ConfigureApplicationContainer (TinyIoCContainer container)
        {
            base.ConfigureApplicationContainer (container);
            Database.SetInitializer<ReflectDbContext> (new NullDatabaseInitializer<ReflectDbContext> ()); // add this to allow prevent "The context cannot be used while the model is being created"
        container.Register<IReflectDbContext, ReflectDbContext> ();
        container.Register<ReflectUnitOfWork> ().AsSingleton ();
        container.Register<IReflectUserRepository, ReflectUserRepository> ();
        container.Register<IUserRepository<ReflectUser>, ReflectUserRepository> ();
        container.Register<IReviewRepository, ReviewRepository> ();
        container.Register<IReviewSetupRepository, ReviewSetupRepository> ();
        container.Register<IRepositoryV2<ReflectUserActivityItem>, EntityFrameworkRepository<ReflectUserActivityItem>> ();
        container.Register<IAuthenticationUnitOfWork<ReflectUser, ReflectUserActivityItem>, ReflectUnitOfWork> ();
        container.Register<IRepository<ReflectUserActivityItem>, NullRepository<ReflectUserActivityItem>> (); //TODO remove this when port is complete
        container.Register<IErrorLogger, SimpleLogLogger> ();
        container.Register<IGeoIpDataProvider, TelizeGeoIpDataProvider> ();
        container.Register<IRepository<ReviewSetup>, ServiceStackOrmLiteRepository<ReviewSetup>> ();
        container.Register<IEmailExporter, MailChimpUserEmailDataExporter> ();
        container.Register<IMailer, SmtpMailer> ();
        container.Register<IUserManager<ReflectUser>, UserManager<ReflectUser, ReflectUserActivityItem>> ();
        container.Register<IUserMessageManager<ReflectUser>, UserMessageManager<ReflectUser>> ();
etc...
}

我有一种感觉，这是一个多线程问题，两个单独的请求使用相同的DbContext(或底层连接)，这导致事情爆发。

我已经尝试在Nancy引导程序的ConfigureRequestContainer方法中注册依赖项，但这会抛出'Connection is not open '异常。

这篇文章清楚地解释了这个问题背后的理论:http://mehdi.me/ambient-dbcontext-in-ef6/

我不明白以下内容:

• 我是否正确地假设这是一个多线程问题?
• 我需要知道正确的方法来确保每个请求使用它自己的DbContext/连接，所以东西不会碰撞，最好使用TinyIoC/Nancy来管理DbContext的生命周期。

我知道这是一个复杂的问题。如果您还需要其他信息，请告诉我。

container.Register<IReflectDbContext, ReflectDbContext> ().AsMultiInstance();