Timeout occured because the target machine actively refused it when writing to MongoDB

Question

I'm trying to write some data to Mongo DB that is hosted on Azure. For this I've created a Cosmos DB account with the API "Azure Cosmos DB for MongoDB API".

To write my data I use this code using .NET Framework 4.7.2 and C#.

string connectionString = "mongodb://<username>:<password>@<host>:<port>/?ssl=true&replicaSet=globaldb&appname=@<region>";
MongoClientSettings settings = MongoClientSettings.FromUrl(new MongoUrl(connectionString));

settings.SslSettings = new SslSettings()
{
    EnabledSslProtocols = SslProtocols.Tls12
};

MongoClient mongoClient = new MongoClient(settings);
IMongoDatabase mongoDatabase = mongoClient.GetDatabase(DatabaseId); // `DatabaseId` is a `string`.
IMongoCollection<TEntity> mongoCollection = mongoDatabase.GetCollection<TEntity>(CollectionId); // `CollectionId` is a `string`.
IEnumerable<WriteModel<TEntity>> entitiesToInsert = entities.Select(entity => new InsertOneModel<TEntity>(entity)); // `entities` is an `IEnumerable<TEntity>` where `TEntity` is `class`.

await mongoCollection.BulkWriteAsync(entitiesToInsert); // → Error on this line.

But on the last line, I've always this exception. It happens not occasionally and retrying fails too. The database and collection name both exists.

TimeoutException: A timeout occured after 30000ms selecting a server using CompositeServerSelector.

MongoConnectionException: An exception occurred while opening a connection to the server.

SocketException: No connection could be made because the target machine actively refused it x.x.x.x:10255

^{Complete log on pastebin.com}

The firewall is configured to allow access from all networks.

Why happens this error and how could I solve this?

Update: By adding the database to the connection string and removing the replicaSet and appname, doesn't solve my problem.

mongodb://<username>:<password>@<host>:<port>/<database>?ssl=true

silent silent · Accepted Answer · 2019-08-19T13:31:02

According to this you are missing the name of the database in the connection string. If none is supplied, it uses test as the db name.

So try this:

string connectionString = "mongodb://xxx:[email protected]:10255/yourdatabase?ssl=true&replicaSet=globaldb&appname=@West Europe";

Timeout occured because the target machine actively refused it when writing to MongoDB

1 Answers