azure - 无法从 Azure Function 连接到 Azure Cosmos DB。获取“Microsoft.Azure.Cosmos.Direct : Object reference not set to an instance of an object

Question

从 Udemy 类(class)获得了 .Net 代码并在我的本地运行。编写了一个连接到 Azure Cosmos DB 并创建项目的 Azure 函数。但无法连接到 Azure Cosmos DB。请参阅下面的代码和错误。感谢任何帮助。在调试中，发现线路存在一些问题

_container.CreateItemAsync(_blobdetails, newPartitionKey(_message.VideoName)).GetAwaiter().GetResult();

Code :

using System;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Azure.Messaging.ServiceBus;
using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;
using Microsoft.Azure.Cosmos;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;

namespace ReceiveMessages
{
    public static class Process
    {
        private static string blob_connection_string = "<blob connection string>";
        private static string source_container_name = "unprocessed";
        private static string destination_container_name = "processed";

        private static readonly string _connection_string = "<cosmos connection string>";
        private static readonly string _database_name = "appdb";
        private static readonly string _container_name = "video";

        [FunctionName("ProcessVideos")]
        public static async Task Run([ServiceBusTrigger("videoqueue", Connection = "connection")]ServiceBusReceivedMessage myQueueItem, ILogger log)
        {
            try
            {
                ReceivedMessage _message = JsonSerializer.Deserialize<ReceivedMessage>(Encoding.UTF8.GetString(myQueueItem.Body));

                BlobServiceClient _client = new BlobServiceClient(blob_connection_string);
                BlobContainerClient _source_container_client = _client.GetBlobContainerClient(source_container_name);
                BlobClient _source_blob_client = _source_container_client.GetBlobClient(_message.VideoName);

                BlobContainerClient _destination_container_client = _client.GetBlobContainerClient(destination_container_name);
                BlobClient _destination_blob_client = _destination_container_client.GetBlobClient(_message.VideoName);

                CosmosClient _cosmosclient = new CosmosClient(_connection_string, new CosmosClientOptions());
                Container _container = _cosmosclient.GetContainer(_database_name, _container_name);

                BlobDownloadInfo _info = _source_blob_client.Download();
                // Copy the blob to the destination container
                await _destination_blob_client.StartCopyFromUriAsync(_source_blob_client.Uri);

                log.LogInformation(_info.Details.LastModified.ToString());
                log.LogInformation(_info.ContentLength.ToString());

                BlobDetails _blobdetails = new BlobDetails();
                _blobdetails.BlobName = _message.VideoName;
                _blobdetails.BlobLocation = "https://videostorage100.blob.core.windows.net/processed/" + _message.VideoName;
                _blobdetails.ContentLength = _info.ContentLength.ToString();
                _blobdetails.LastModified = _info.Details.LastModified.ToString();
                _blobdetails.id = Guid.NewGuid().ToString();

                _container.CreateItemAsync(_blobdetails, new PartitionKey(_message.VideoName)).GetAwaiter().GetResult();
                Console.WriteLine("Item created");

                // Delete the blob from the unprocessed container
                _source_blob_client.Delete();
                // Add the details of the blob to an Azure Cosmos DB account

            }
            catch (Exception ex)
            {
                string s = ex.Message;
            }



        }
    }
}


    

* Executed 'ProcessVideos' (Failed, Id=53b3d0b2-d46a-4ba9-bf26-d8de76af0bce, Duration=41001ms)
[2022-03-19T23:07:25.845Z] Executed 'ProcessVideos' (Failed, Id=48b50a3d-f69f-436f-accf-5140c3d7f8a0, Duration=41001ms)
[2022-03-19T23:07:25.854Z] System.Private.CoreLib: Exception while executing function: ProcessVideos. Microsoft.Azure.Cosmos.Direct: Object reference not set to an instance of an object.{"name":"CreateItemAsync","id":"c16e23cd-badc-4f0b-a940-3fac7f52c4f7","caller info":{"member":"OperationHelperWithRootTraceAsync","file":"ClientContextCore.cs","line":219},"start time":"11:06:46:894","duration in milliseconds":36808.7271,"data":{"Client Configuration":{"Client Created Time Utc":"2022-03-19T23:06:45.5706176Z","NumberOfClientsCreated":3,"User Agent":"cosmos-netstandard-sdk/3.19.0|3.19.1|08|X64|Microsoft Windows 10.0.19043|.NET Core 3.1.20|N|","ConnectionConfig":{"gw":"(cps:50, urto:10, p:False, httpf: False)","rntbd":"(cto: 5, icto: -1, mrpc: 30, mcpe: 65535, erd: False, pr: ReuseUnicastPort)","other":"(ed:False, be:False)"},"ConsistencyConfig":"(consistency: NotSet, prgns:[])"}},"children":[{"name":"ItemSerialize","id":"647e3fbb-bd9f-4b12-9367-3ed1f6c4d436","caller info":{"member":"ExtractPartitionKeyAndProcessItemStreamAsync","file":"ContainerCore.Items.cs","line":931},"start time":"11:06:46:921","duration in milliseconds":20.2124},{"name":"Microsoft.Azure.Cosmos.Handlers.RequestInvokerHandler","id":"23650859-deb4-44e1-a696-daeeab7564c8","start time":"11:06:47:893","duration in milliseconds":35799.6699,"children":[{"name":"Microsoft.Azure.Cosmos.Handlers.DiagnosticsHandler","id":"f18265a9-2a93-46c8-aa05-78b69ed30086","start time":"11:06:47:927","duration in milliseconds":35763.5861,"data":{"CPU Load History":{"CPU History":"(2022-03-19T23:06:47.9376170Z 38.049)"}},"children":[{"name":"Microsoft.Azure.Cosmos.Handlers.RetryHandler","id":"876ad64c-0dc3-42a2-9a47-4054ec301b57","start time":"11:06:47:945","duration in milliseconds":35744.6099,"children":[{"name":"Microsoft.Azure.Cosmos.Handlers.RouterHandler","id":"01ca2b19-39c0-477d-ad85-f930397e682a","start time":"11:06:47:954","duration in milliseconds":35729.8987,"children":[{"name":"Microsoft.Azure.Cosmos.Handlers.TransportHandler","id":"e372af16-b68c-438d-9ae1-2fdaad2d5f23","start time":"11:06:47:955","duration in milliseconds":35720.3525,"children":[{"name":"Microsoft.Azure.Documents.ServerStoreModel Transport Request","id":"9995478e-5933-4b21-8c08-cf03501ebe03","caller info":{"member":"ProcessMessageAsync","file":"TransportHandler.cs","line":109},"start time":"11:06:47:963","duration in milliseconds":35704.0196,"data":{"Client Side Request Stats":{"Id":"AggregatedClientSideRequestStatistics","ContactedReplicas":[{"Count":1,"Uri":"rntbd://cdb-ms-prod-westus1-fd76.documents.azure.com:14059/apps/0152c08e-edca-4977-bca0-40bb4325ee70/services/117845df-eb50-4f9a-8f97-0a5981cfeaae/partitions/1e48d158-7844-4a7c-89a0-aa99c17adcb8/replicas/132920901445077053s/"},{"Count":1,"Uri":"rntbd://cdb-ms-prod-westus1-fd76.documents.azure.com:14352/apps/0152c08e-edca-4977-bca0-40bb4325ee70/services/117845df-eb50-4f9a-8f97-0a5981cfeaae/partitions/1e48d158-7844-4a7c-89a0-aa99c17adcb8/replicas/132920901532421814s/"},{"Count":1,"Uri":"rntbd://cdb-ms-prod-westus1-fd76.documents.azure.com:14095/apps/0152c08e-edca-4977-bca0-40bb4325ee70/services/117845df-eb50-4f9a-8f97-0a5981cfeaae/partitions/1e48d158-7844-4a7c-89a0-aa99c17adcb8/replicas/132920901532421816s/"}],"RegionsContacted":["https://videodbupdate-westus.documents.azure.com/"],"FailedReplicas":[],"AddressResolutionStatistics":[{"StartTimeUTC":"2022-03-19T23:06:48.3431877Z","EndTimeUTC":"2022-03-19T23:06:48.4598190Z","TargetEndpoint":"https://videodbupdate-westus.documents.azure.com//addresses/?$resolveFor=dbs%2fHdYjAA%3d%3d%2fcolls%2fHdYjAIRIK9s%3d%2fdocs&$filter=protocol eq rntbd&$partitionKeyRangeIds=0"},{"StartTimeUTC":"2022-03-19T23:06:54.7678280Z","EndTimeUTC":"2022-03-19T23:06:54.8820135Z","TargetEndpoint":"https://videodbupdate-westus.documents.azure.com//addresses/?$resolveFor=dbs%2fHdYjAA%3d%3d%2fcolls%2fHdYjAIRIK9s%3d%2fdocs&$filter=protocol eq rntbd&$partitionKeyRangeIds=0"},{"StartTimeUTC":"2022-03-19T23:07:01.6288211Z","EndTimeUTC":"2022-03-19T23:07:01.7399788Z","TargetEndpoint":"https://videodbupdate-westus.documents.azure.com//addresses/?$resolveFor=dbs%2fHdYjAA%3d%3d%2fcolls%2fHdYjAIRIK9s%3d%2fdocs&$filter=protocol eq rntbd&$partitionKeyRangeIds=0"},{"StartTimeUTC":"2022-03-19T23:07:09.6372169Z","EndTimeUTC":"2022-03-19T23:07:09.7484346Z","TargetEndpoint":"https://videodbupdate-westus.documents.azure.com//addresses/?$resolveFor=dbs%2fHdYjAA%3d%3d%2fcolls%2fHdYjAIRIK9s%3d%2fdocs&$filter=protocol eq rntbd&$partitionKeyRangeIds=0"},{"StartTimeUTC":"2022-03-19T23:07:17.9939496Z","EndTimeUTC":"2022-03-19T23:07:18.1025134Z","TargetEndpoint":"https://videodbupdate-westus.documents.azure.com//addresses/?$resolveFor=dbs%2fHdYjAA%3d%3d%2fcolls%2fHdYjAIRIK9s%3d%2fdocs&$filter=protocol eq rntbd&$partitionKeyRangeIds=0"}],"*

*[2022-03-19T23:07:25.848Z] System.Private.CoreLib: Exception while executing function: ProcessVideos. Microsoft.Azure.Cosmos.Client: Response status code does not indicate success: ServiceUnavailable (503); Substatus: 0; ActivityId: 349d6ef1-4696-4ec8-88c9-5913129164ec; Reason: (Service is currently unavailable. More info: https://aka.ms/cosmosdb-tsg-service-unavailable
[2022-03-19T23:07:26.012Z] System.Private.CoreLib: Exception while executing function: ProcessVideos. Microsoft.Azure.Cosmos.Client: Response status code does not indicate success: ServiceUnavailable (503); Substatus: 0; ActivityId: 40f51724-2bf3-46b2-ac99-c9030aed41c6; Reason: (Service is currently unavailable. More info: https://aka.ms/cosmosdb-tsg-service-unavailable
[2022-03-19T23:07:26.040Z] ActivityId: 349d6ef1-4696-4ec8-88c9-5913129164ec, Microsoft.Azure.Cosmos.Tracing.TraceData.ClientSideRequestStatisticsTraceDatum, Windows/10.0.19043 cosmos-netstandard-sdk/3.19.1);. Microsoft.Azure.Cosmos.Direct: Message: The requested resource is no longer available at the server.*

Answer 1

此问题已在 SDK 3.20 中修复:https://github.com/Azure/azure-cosmos-dotnet-v3/blob/master/changelog.md#-3200---2021-06-21

请升级到recommended version以获得此修复和其他修复。

更多修复

您正在为每个函数执行创建一个客户端(Blob 和 Cosmos)，这违背了建议，并且会随着队列消息数量的增加而带来问题，请遵循 https://learn.microsoft.com/azure/azure-functions/manage-connections?tabs=csharp#static-clients并使用单例/静态实例。我们有一个关于如何将 DI 和函数与 CosmosClient 结合使用的完整示例，网址为 https://github.com/Azure/azure-cosmos-dotnet-v3/tree/master/Microsoft.Azure.Cosmos.Samples/Usage/AzureFunctions .

此外，不要阻止线程，因为您的函数已经是异步的，因此请改为 await _container.CreateItemAsync(_blobdetails, new PartitionKey(_message.VideoName))。

大多数情况下，这两点会生成这些“服务不可用”错误。

同样非常重要的是，您的帖子包含服务 key 和连接字符串(我已编辑将其删除，但它们已经暴露)，请立即轮换它们