Unable to connect to Azure Cosmos Db Account using Microsoft.EntityFrameworkCore.Cosmos - Response status code

Question

The CosmosDb provider is sending this message:

“Response status code does not indicate success: 503 Substatus: 0 Reason: (The request failed because the client was unable to establish connections to 3 endpoints across 1 regions. Please check for client resource starvation issues and verify connectivity between client and server.”

In my tests, it works (.net core 3.1):

Task.Run(async () =>
        {
            var endpoint = “test”;
            var masterKey = “test”;
            using (var client = new DocumentClient(new Uri(endpoint), masterKey))
            {
                //Insert new Document  
                Console.WriteLine("\r\n>>>>>>>>>>>>>>>> Creating Document <<<<<<<<<<<<<<<<<<<");
                dynamic candidato = new
                {
                    Id = 1,
                    Nome = "Test"
                };

                var document1 = await client.CreateDocumentAsync(
                    UriFactory.CreateDocumentCollectionUri("Test", "Test"),
                    candidato);

                Console.ReadKey();
            }

        }).Wait();

It does not:

            Task.Run(async () =>
            {
                using (var context = new StudentsDbContext())
                {
                    context.Add(new FamilyContainer(2, "Test"));
                    await context.SaveChangesAsync();
                }

            }).Wait();

public class FamilyContainer
{
    public int Id { get; set; }
    public string Nome { get; set; }

    public FamilyContainer(int id, string nome)
    {
        Id = id;
        Nome = nome;
    }

}

public class StudentsDbContext : DbContext
{
    public DbSet<FamilyContainer> FamilyContainer { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseCosmos(
           "test",
           "test",
           "FamilyDatabase",
           options =>
           { }
         );
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<FamilyContainer>(x =>
        {
            x.ToContainer("FamilyContainer");
        });
    }
}

Packages

Can anyone help me? Thanks

fail: Microsoft.EntityFrameworkCore.Update[10000] An exception occurred in the database while saving changes for context type '...'. Microsoft.EntityFrameworkCore.Storage.RetryLimitExceededException: Maximum number of retries (6) exceeded while executing database operations with 'CosmosExecutionStrategy'. See inner exception for the most recent failure. ---> Microsoft.Azure.Cosmos.CosmosException : Response status code does not indicate success: 503 Substatus: 0 Reason: (Microsoft.Azure.Documents.ServiceUnavailableException: Service is currently unavailable.ActivityId: 07fbf539-0d44-4e5a-89d0-cd46838ee605, {"RequestStartTimeUtc":"2020-02-21T16:34:09.1834993Z","RequestEndTimeUtc":"2020-02-21T16:34:41.3484203Z","RequestLatency":"00:00:32.1649210","IsCpuOverloaded":false,"NumberRegionsAttempted":1,"ResponseStatisticsList":[{"ResponseTime":"2020-02-21T16:34:11.5964152Z","ResourceType":2,"OperationType":0,"StoreResult":"StorePhysicalAddress: rntbd:.../, LSN: -1, GlobalCommittedLsn: -1, PartitionKeyRangeId: , IsValid: True, StatusCode: 410, SubStatusCode: 0, RequestCharge: 0, ItemLSN: -1, SessionToken: , UsingLocalLSN: False, TransportException: A client transport error occurred: Failed to connect to the remote endpoint. (Time: 2020-02-21T16:34:11.5298608Z, activity ID: 07fbf539-0d44-4e5a-89d0-cd46838ee605, error code: ConnectFailed [0x0005], base error: socket error ConnectionRefused [0x0000274D]... --- End of inner exception stack trace ---

Answer 1

I was facing same issue.

What worked for me is changing ConnectionMode to ConnectionMode.Gateway while initializing CosmosClient like :

var options = new CosmosClientOptions() { ConnectionMode = ConnectionMode.Gateway };
var client = new CosmosClient(endpoint, key, options); 

For more details on refer :

https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.cosmos.cosmosclientoptions?view=azure-dotnet

https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.cosmos.connectionmode?view=azure-dotnet