Unable to connect to MongoDb using MongoClientSettings as parameter to MongoClient - mongodb

Question

I am developing a C# MVC Web API which uses MongoDb as backend.I tried connecting to my mongodb database using
MongoClient mongoClient = new MongoClient(connectionString)
where connectionstring is in format : mongodb://Username:Password#hostname.eastus.cloudapp.azure.com
Mongo db is hosted in a virtual machine in Azure.I am able to connect to the database and all works good.But I am getting frequent exceptions:
"MongoDb.driver.MongoConnectionException".An exception occurred while
receivinf a message from server--->System.IO.IOException:Unable to
read data from the transport connection : A connection attempt failed
because the connected party did not properly respond after a period of
time,......"
So after a bit of research I have learnt that Azure is killing idle connections and I have to set MaxConnectionIdleTime.
In order to set MaxConnectionIdleTime I decided to connect to Mongodb in the below way
var credential = MongoCredential.CreateCredential("dbname", "UserName", "Password");
var settings = new MongoClientSettings
{
Credentials = new[] { credential },
Server = new MongoServerAddress("HostName", 27017),
MaxConnectionIdleTime = new TimeSpan(0, 3, 0)
};
MongoClient mongoClient = new MongoClient(settings);
In this case I am using the same username,password combination given in the connection string which I used to connect before.
While trying to connect here I am getting inner Exception:
MongoDB.Driver.MongoAuthenticationException: "Unable to authenticate
using sasl protocol mechanism SCRAM-SHA-1".

Answer 1

"MongoDb.driver.MongoConnectionException".An exception occurred while receivinf a message from server--->System.IO.IOException:Unable to read data from the transport connection : A connection attempt failed because the connected party did not properly respond after a period of time,....
The reason behind this exception is when hosted in Azure,Azure tries to kill the idle connections but the C# driver is not aware of this.The driver tries to execute queries on the killed connections without knowing the connection is not existing.
The solution that worked out for me is to set maxIdleTimeMS=45000 in connection string.
This way driver will not use a connection which has been idle for long time.
Here is the connection string that worked out for me
connectionString="Username:Password#hostname.eastus.cloudapp.azure.com/?connectTimeoutMS=30000&socketTimeoutMS=30000&waitQueueTimeoutMS=30000&maxIdleTimeMS=45000"

Answer 2

I have had a similar error with my Azure hosted MongoDb (Cosmos Db). It turned out to be network settings such that I had blocked all access. Changing it to Allow access from "All networks" fixed the issue.
The error is very misleading, I would have expected a connection timeout.
A timeout occured after 30000ms selecting a server using
CompositeServerSelector{ Selectors =
MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector,
LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000
} }. Client view of cluster state is { ClusterId : "1", ConnectionMode
: "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers :
[{ ServerId: "{ ClusterId : 1, EndPoint :
"Unspecified/XXXX.documents.azure.com:10255" }", EndPoint:
"Unspecified/XXXX.documents.azure.com:10255", State: "Disconnected",
Type: "Unknown", HeartbeatException:
"MongoDB.Driver.MongoConnectionException: An exception occurred while
opening a connection to the server. --->
MongoDB.Driver.MongoAuthenticationException: Unable to authenticate
using sasl protocol mechanism SCRAM-SHA-1. --->
MongoDB.Driver.MongoCommandException: Command saslContinue failed: Not
Authenticated.
To troubleshot I tried from MongoDb Compass as well and that didn't work either, showing me it wasn't the code.