System.Uri error in Container.ReadThroughputAsync

Describe the bug When calling Container.ReadThroughputAsync() on a non-null container that has a throughput value (400 in this case), CosmosOffers.ReadThroughputAsync fails due to a “Value cannot be null” error in the System.Uri constructor.

To Reproduce

Get a container and call ReadThroughputAsync() on it:

CosmosClient _cosmosClient = new CosmosClient(
    _configuration.Endpoint,
    _configuration.AuthKey,
    new CosmosClientOptions
    {
        ConnectionMode = _configuration.ConnectionMode,
        ConsistencyLevel = ConsistencyLevel.Session,
        GatewayModeMaxConnectionLimit = _configuration.MaxConnectionLimit,
        RequestTimeout = _configuration.RequestTimeout,
        MaxRetryAttemptsOnRateLimitedRequests = _configuration.MaxRetryAttemptsOnThrottledRequests,
        MaxRetryWaitTimeOnRateLimitedRequests = TimeSpan.FromSeconds(_configuration.MaxRetryWaitTimeInSeconds),
        Serializer = new CosmosJsonSerializer(_jsonSerializer), // Custom CosmosSerializer
    });
Database database = await _cosmosClient.CreateDatabaseIfNotExistsAsync(databaseId);
await database.CreateContainerIfNotExistsAsync(containerId, _configuration.PartitionKey, 400);
Container container = _cosmosClient.GetContainer(databaseId, containerId);
int? throughput = await container.ReadThroughputAsync();

Expected behavior

The method should return a value (in my case, I expect 400).

Actual behavior

A System.ArgumentNullException is thrown (see message and stack trace below).

Environment summary SDK Version: 3.1.1 OS Version (e.g. Windows, Linux, MacOSX): Windows

Additional context

Exception message:

Value cannot be null.
Parameter name: uriString

Stack trace:

   at System.Uri..ctor(String uriString, UriKind uriKind)
   at Microsoft.Azure.Cosmos.CosmosOffers.<ReadThroughputAsync>d__3.MoveNext()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Azure.Cosmos.ContainerCore.<ReadThroughputAsync>d__24.MoveNext()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Azure.Cosmos.ContainerCore.<ReadThroughputAsync>d__23.MoveNext()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at AH.DS.Online.Common.Providers.CosmosDB.DocumentClientAdapter.<ElasticScaleCollectionThroughputAsync>d__21.MoveNext() in C:\Users\b_b\source\repos\ah-ds-online\src\ah-ds-online-common\Common.Providers.CosmosDB\DocumentClientAdapter.cs:line 197
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at AH.DS.Online.Publisher.Common.Services.ThroughputScaleService.<ScaleUpThroughputAsync>d__3.MoveNext() in C:\Users\b_b\source\repos\ah-ds-online\src\ah-ds-online-publisher\Publisher.Common\Services\ThroughputScaleService.cs:line 23
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at AH.DS.Online.Publisher.Common.Commands.MetadataProcessorCommand.<Execute>d__4.MoveNext() in C:\Users\b_b\source\repos\ah-ds-online\src\ah-ds-online-publisher\Publisher.Common\Commands\MetadataProcessorCommand.cs:line 36

[Druid-of-Luhn]

We have tried a reduced test case in a Console App, and cannot replicate the issue: reading and replacing the throughput work as expected.

The main thing that was changed when updating to Cosmos SDK 3 was adding the custom CosmosSerializer (a wrapper around Newtonsfot.Json). Could that be the culprit?

public class CosmosJsonSerializer : CosmosSerializer
{
    private readonly IJsonSerializer _jsonSerializer;

    public CosmosJsonSerializer(IJsonSerializer jsonSerializer)
    {
        _jsonSerializer = jsonSerializer;
    }

    public override T FromStream<T>(Stream stream)
    {
        using (StreamReader reader = new StreamReader(stream))
        {
            return _jsonSerializer.DeserializeObject<T>(reader.ReadToEnd());
        }
    }

    public override Stream ToStream<T>(T input)
    {
        string serialized = _jsonSerializer.SerializeObject(input);
        // Do not close the stream (either the Stream or the StreamWriter),
        // as the returned stream should still be open
        Stream stream = new MemoryStream();
        StreamWriter writer = new StreamWriter(stream);
        writer.Write(serialized);
        writer.Flush();
        stream.Seek(0, SeekOrigin.Begin);
        return stream;
    }
}

[simplynaveen20]

Yea sound reasonable , custom serializer could play the role here. Will pick this item next week. Thanks for all the detail explanation of the issue , really appreciate that.