我们最近更新了我们的机器人，使用以下文章将其从即将弃用的默认BotState服务迁移到Azure Cosmos DB存储中：
https://docs.microsoft.com/en-us/bot-framework/dotnet/bot-builder-dotnet-state-azure-cosmosdb
以下模块以Application_Start方法在会话容器中注册：
public class CustomBotStateServiceModule : Module
{
protected override void Load(ContainerBuilder builder)
{
var stateStore = new DocumentDbBotDataStore(
new Uri(ConfigurationManager.AppSettings.Get("EndpointUri")),
ConfigurationManager.AppSettings.Get("PrimaryKey"),
ConfigurationManager.AppSettings.Get("DatabaseId"),
"BotState");
builder.Register(c => stateStore)
.Keyed<IBotDataStore<BotData>>(AzureModule.Key_DataStore)
.AsSelf()
.SingleInstance();
builder.Register(c => new CachingBotDataStore(stateStore, CachingBotDataStoreConsistencyPolicy.ETagBasedConsistency))
.As<IBotDataStore<BotData>>()
.AsSelf()
.InstancePerLifetimeScope();
}
}
在使用Bot Channel Emulator进行本地测试期间，我们注意到，每次首次访问BotState时，都会在Visual Studio的Debug输出中打印以下错误：
DocDBTrace Information: 0 : DocumentClient with id 1 initialized at endpoint: https://<our-instance>.documents.azure.com/ with ConnectionMode: Gateway, connection Protocol: Https, and consistency level: null
DocDBTrace Information: 0 : RefreshLocationAsync() refreshing locations
DocDBTrace Information: 0 : Set WriteEndpoint https://<our-instance>-westus.documents.azure.com/ ReadEndpoint https://<our-instance>-westus.documents.azure.com/
DocDBTrace Error: 0 : DocumentClientException with status code: NotFound, message: Message: {"Errors":["Resource Not Found"]}
ActivityId: <activity-id>, Request URI: /apps/<app-id>/services/<service-id>/partitions/<partition-id>/replicas/<replica-id>/, RequestStats:
ResponseTime: 2018-01-25T08:20:59.3067000Z, StoreReadResult: StorePhysicalAddress: rntbd://<docdb-location>.documents.azure.com:14043/apps/<app-id>/services/<service-id>/partitions/<partition-id>/replicas/<replica-id>/, LSN: 154, GlobalCommittedLsn: 151, PartitionKeyRangeId: 0, IsValid: True, StatusCode: 0, IsGone: False, IsNotFound: True, RequestCharge: 1, ItemLSN: -1, ResourceType: Document, OperationType: Read
, SDK: Microsoft.Azure.Documents.Common/1.19.162.2, and response headers: {
"x-ms-last-state-change-utc": "Wed, 24 Jan 2018 00:00:51.902 GMT",
"x-ms-schemaversion": "1.4",
"x-ms-xp-role": "1",
"x-ms-global-Committed-lsn": "151",
"x-ms-number-of-read-regions": "0",
"x-ms-request-charge": "1",
"x-ms-serviceversion": "version=1.19.162.2",
"x-ms-activity-id": "<activity-id>",
"Strict-Transport-Security": "max-age=31536000",
"x-ms-gatewayversion": "version=1.19.162.2",
"X-Cache": "MISS from <node>",
"Transfer-Encoding": "chunked",
"Connection": "keep-alive",
"Date": "Thu, 25 Jan 2018 08:20:58 GMT",
"Server": "Microsoft-HTTPAPI/2.0",
"Via": "1.1 <node> (squid)",
}
DocDBTrace Error: 0 : Operation will NOT be retried. Current attempt 0, Exception: Microsoft.Azure.Documents.DocumentClientException: Message: {"Errors":["Resource Not Found"]}
ActivityId: <activity-id>, Request URI: /apps/<app-id>/services/<service-id>/partitions/<partition-id>/replicas/<replica-id>/, RequestStats:
ResponseTime: 2018-01-25T08:20:59.3067000Z, StoreReadResult: StorePhysicalAddress: rntbd://<docdb-location>.documents.azure.com:14043/apps/<app-id>/services/<service-id>/partitions/<partition-id>/replicas/<replica-id>/, LSN: 154, GlobalCommittedLsn: 151, PartitionKeyRangeId: 0, IsValid: True, StatusCode: 0, IsGone: False, IsNotFound: True, RequestCharge: 1, ItemLSN: -1, ResourceType: Document, OperationType: Read
, SDK: Microsoft.Azure.Documents.Common/1.19.162.2, documentdb-dotnet-sdk/1.19.1 Host/32-bit MicrosoftWindowsNT6.1.7601ServicePack1
at Microsoft.Azure.Documents.Client.ClientExtensions.<ParseResponseAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
at Microsoft.Azure.Documents.GatewayStoreModel.<>c__DisplayClass10.<<InvokeAsync>b__f>d__12.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<>c__DisplayClass2.<<ExecuteAsync>b__0>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<ExecuteRetry>d__1b.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<ExecuteRetry>d__1b.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<ExecuteAsync>d__a.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.GatewayStoreModel.<InvokeAsync>d__1f.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.GatewayStoreModel.<ProcessMessageAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.Client.DocumentClient.<ReadAsync>d__30c.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.Client.DocumentClient.<ReadDocumentPrivateAsync>d__18d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<>c__DisplayClass2.<<ExecuteAsync>b__0>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Documents.BackoffRetryUtility`1.<ExecuteRetry>d__1b.MoveNext()
此后不久，这些错误会再打印1-2次。尽管如此，自定义的BotState服务似乎可以正常运行，因为我们可以看到在相关Cosmos DB集合中创建的条目。
注意：我们并非仅使用Cosmos DB来存储BotState数据。我们还使用它来存储漫游器活动数据，日志等。它目前具有两个具有多个集合的数据库。
这些错误的根本原因是什么？这是我们应该考虑的事情吗？一旦我们从容器注册中拔出了自定义BotState服务，错误就消失了。
最佳答案
根据我的测试和研究，我可以从侧面再现问题，我发现当我们要将状态数据存储到Azure Cosmos DB集合时，Azure SDK可以帮助我们检查文档是否存在，因此您可以看到该输出消息：bot应用程序首次存储数据时，在Visual Studio输出窗口中显示"Resource Not Found"。
如果使用Fiddler捕获流量，则可以发现SDK发出请求以检测该集合中是否存在该文档。
如您所见，它只是由SDK编写的输出消息，不会在您的代码中引起任何代码异常。
关于c# - 实现自定义BotState服务后，Cosmos DB引发“找不到资源”错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/48441262/