我们将 Sagas 与 Azure 持久性结合使用。
我们有一个可以与用户会话处理程序进行比较的传奇。该会话的唯一键是用户的手机号码。第一次收到短信时，会为该手机号码创建一个传奇。saga 数据记录和二级索引在 Azure 表存储中创建。
过了一会儿，saga 被标记为已完成。saga 数据条目被删除，但二级索引仍保留在表存储中。
又过了一会儿，收到了来自同一个手机号码的新消息。该手机号码没有活动的 saga，因此创建了一个新实例（但与历史完成的 saga 具有相同的 sagaId 可能是因为二级索引仍然存在）。由于以下异常，未处理启动 saga 的消息：
NServiceBus.SagaPersisters.Azure.RetryNeededException: This operation requires a retry as it wasn't possible to successfully process it now.
at NServiceBus.SagaPersisters.Azure.SecondaryIndeces.SecondaryIndexPersister.Insert(IContainSagaData sagaData) in C:\BuildAgent\work\32a824616368e685\src\NServiceBus.Azure\SagaPersisters\Azure\SecondaryIndeces\SecondaryIndexPersister.cs:line 89
at NServiceBus.SagaPersisters.Azure.AzureSagaPersister.Save(IContainSagaData saga) in C:\BuildAgent\work\32a824616368e685\src\NServiceBus.Azure\SagaPersisters\Azure\AzureSagaPersister.cs:line 47
at NServiceBus.SagaPersistenceBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Sagas\SagaPersistenceBehavior.cs:line 118
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.SetCurrentMessageBeingHandledBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Behaviors\SetCurrentMessageBeingHandledBehavior.cs:line 17
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.LoadHandlersBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Behaviors\LoadHandlersBehavior.cs:line 45
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.InvokeSagaNotFoundBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Behaviors\InvokeSagaNotFoundBehavior.cs:line 17
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.ExecuteLogicalMessagesBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Messages\ExecuteLogicalMessagesBehavior.cs:line 24
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.UnitOfWorkBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\UnitOfWork\UnitOfWorkBehavior.cs:line 42
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.ChildContainerBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Behaviors\ChildContainerBehavior.cs:line 17
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.<>c__DisplayClass4_0.<InvokeNext>b__0() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 95
at NServiceBus.ProcessingStatisticsBehavior.Invoke(IncomingContext context, Action next) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Monitoring\ProcessingStatisticsBehavior.cs:line 23
at NServiceBus.BehaviorChain`1.InvokeNext(T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 107
at NServiceBus.BehaviorChain`1.Invoke() in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\BehaviorChain.cs:line 52
at NServiceBus.Pipeline.PipelineExecutor.Execute[T](BehaviorChain`1 pipelineAction, T context) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Pipeline\PipelineExecutor.cs:line 129
at NServiceBus.Unicast.Transport.TransportReceiver.OnTransportMessageReceived(TransportMessage msg) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Transport\TransportReceiver.cs:line 413
at NServiceBus.Unicast.Transport.TransportReceiver.ProcessMessage(TransportMessage message) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Transport\TransportReceiver.cs:line 344
at NServiceBus.Unicast.Transport.TransportReceiver.TryProcess(TransportMessage message) in C:\BuildAgent\work\3206e2123f54fce4\src\NServiceBus.Core\Unicast\Transport\TransportReceiver.cs:line 230
at NServiceBus.Azure.Transports.WindowsAzureServiceBus.AzureServiceBusDequeueStrategy.TryProcessMessage(Object obj) in C:\BuildAgent\work\2f57832e2eee436e\src\Transport\Receiving\AzureServiceBusDequeueStrategy.cs:line 137
当然，我可以通过保持 saga “运行”并在 saga 数据中设置一个内部标志来解决这个问题，无论会话是否处于活动状态。但是，我想知道为什么在 Saga 完成时没有删除二级索引？有什么我忘记了吗？使用相同的唯一键启动 saga 的新实例是一个糟糕的设计吗？
提前感谢您的回答/评论。
环境：
- NServiceBus 5.2.4
- NServiceBus.Azure 6.2.4