Azure Cosmos DB - intermittent MongoConnectionException / IOException / SocketException - mongodb

I'm using Azure Cosmos DB 4.0 with MongoDB C# Driver 2.10.4.
Most of the times the queries work fine, but I'm getting intermittent errors like this:
MongoDB.Driver.MongoConnectionException: An exception occurred while sending a message to the server.
System.IO.IOException: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.
System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.BeginSend(...
at System.Net.Sockets.NetworkStream.BeginWrite
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.BeginWrite
at System.Net.Security._SslStream.StartWriting
at System.Net.Security._SslStream.ProcessWrite
at System.Net.Security._SslStream.BeginWrite
When that error happens the call takes 10-25 seconds before failing.
I'm building the MongoClient with new MongoClient(MongoClientSettings.FromConnectionString(cnstr)) and I was using the connectionstring with these arguments ?ssl=true&replicaSet=globaldb&retrywrites=false.
I tried with retryWrites=true (as per Azure Support suggestion) but that didn't help.
I tried different settings and that didn't work either (connect=direct, maxIdleTimeMS=30000, serverSelectionTimeout=5000ms, socketTimeout=10000ms).
What's causing those exceptions?

The fix was to set/force TLS 1.2 (based on this Microsoft document):
//return new MongoClient(connectionString);
var settings = MongoClientSettings.FromConnectionString(connectionString);
settings.SslSettings = new SslSettings()
{
EnabledSslProtocols = System.Security.Authentication.SslProtocols.Tls12
};
return new MongoClient(settings);
Looks like although my connection string had ssl=true, it wasn't enough to work on some servers (the error is intermittent). The same underlying error can usually be fixed by forcing TLS 1.2 so I assumed that in Mongo it could be the same issue - and it really fixed the problem.

Related

quickstart error - Using EF Migrations for local SQL Server and keep loosing db connection

I am following IdentityServer4 quickstart and trying to migrate in memory data to my local SQL Server (not SQL express or LocalDB that came with VS). My connection string is:
#"Server=localhost,1434;Database=MyIDS;user id=tester_1;Password=tester_1;trusted_connection=yes;".
When I start my IdentityServer, it creates the enpty db, MyIDS, and then throw an exception with 2 inner exceptions:
Inner Exception 1:
SqlException: A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 - An established connection was aborted by the software in your host machine.)
Inner Exception 2:
Win32Exception: An established connection was aborted by the software in your host machine.
Can anyone tell me what's going on here? Why a working connection always gets dropped?
localhost,1434 looks wrong, you don't need to provide the port 1434 and the commma should not be used either, it should be a colon in that case.
I typically use for local development:
server=.;Database=ASPIdentity;Trusted_Connection=True;
dot means localhost, if you use sqlexpress the connetion string would become
server=.\\sqlexpress;Database=ASPIdentity;Trusted_Connection=True;

MongoConnectionTimeOut is not working using the MongoClientURI

I am trying to connect MongoDB using MongoClientURI(URL) my URL is mongodb://userName:Password#host:PortNumber/DBName?connectTimeoutMS=10000
when my MongoDB is Down i try to Post Request but it take default time 30 sec.
Can any one help me solve the problem
Thanks in Advance.
You can set timeouts by using the Mongo Java client's MongoClientOptions. For example:
MongoClientOptions clientOptions = MongoClientOptions.builder()
.connectTimeout(...)
.socketTimeout(...)
.serverSelectionTimeout(...)
.build();
MongoClient mongoClient = new MongoClient(new ServerAddress(host, port), clientOptions);
Examining mongoClient.getMongoClientOptions() after the above line of code clearly shows that the created client is faithful to the supplied config values. By contrast, if you do not set these values via MongoClientOptions then mongoClient.getMongoClientOptions() shows that the default values have been chosen.
Based on your updated comments I think the situation you are trying to cater for is this:
Creating a connection against a server instance which does not exists / is unavailable should fail sooner that the default of 30s.
If so then the configuration parameter you want to use is serverSelectionTimeout. The following invocation ...
MongoClientOptions clientOptions = MongoClientOptions.builder()
.serverSelectionTimeout(2000)
.build();
MongoClient mongoClient = new MongoClient(new ServerAddress(host, port), clientOptions);
... will cause this exception to be thrown:
com.mongodb.MongoTimeoutException: Timed out after 2000 ms while waiting to connect.
Note: serverSelectionTimeout is available in the version of the MongoDB Java driver which you are using (3.2.2 according to the comment you posted on your question).

Npgsql throws an error: wrong connection string. Can't connect to postgreSQL [F#]

I'm using SQLProvider to connect to my (local) PostgreSQL database in F#.
I've started with this code from fsprojects:
open FSharp.Data.Sql
open Npgsql
let [<Literal>] ResolutionPath =
__SOURCE_DIRECTORY__ + #"/../../packages/Npgsql/lib/net451/"
[<Literal>]
let connectionString = "Host=localhost;Port=5432;User ID=test;Password=test;Database=testdb;"
type PostgreSQL =
SqlDataProvider<
Common.DatabaseProviderTypes.POSTGRESQL,
ConnectionString = connectionString,
ResolutionPath = ResolutionPath,
IndividualsAmount = 1000,
UseOptionTypes = true>
When I'm trying to compile it I get this error message:
(path)/Database.fs(60,9): error FS3033: The type provider 'FSharp.Data.Sql.SqlTypeProvider' reported an error: Could not create the connection, most likely this means that the connectionString is wrong. See error from Npgsql to troubleshoot: The type initializer for 'Npgsql.Counters' threw an exception.
(path)/Database.fs(60,9): error FS3033: The type provider 'FSharp.Data.Sql.SqlTypeProvider' reported an error: Could not create the connection, most likely this means that the connectionString is wrong. See error from Npgsql to troubleshoot: The type initializer for 'Npgsql.Counters' threw an exception.
I've checked that user id and password and everything in connection string is correct.
I actually don't have any idea how to debug this issue.
Do you know what could be wrong?
Does it work for you without any issues?
I'm using macOS 10.12.
And lastly, in case I won't be able to fix this, are there any other methods that you would recommend for connecting to postgreSQL (with type providers)?
The error message clearly says that an exception was thrown from the type initializer for Npgsql.Counters - this is Npgsql 3.2's new support for Windows performance counters.
Unfortunately it seems that there are several issues with performance counters in various scenario (see #1447 and #1435). Because of this, version 3.2.2 (to be released this week) won't make use of them by default.
Can you please confirm that you're using 3.2.1 (and not 3.2.0), because a partial fix was introduced? If you're using 3.2.1 and getting this exception, you'll have to wait a few days for 3.2.0, and can use 3.1.10 in the meantime where the exception won't be thrown.

Unable to connect to MongoDb using MongoClientSettings as parameter to MongoClient

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".
"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"
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.

MongoInternalException: DBPort.findOne failed while running on GAE localserver

I am trying to connect to remote MongoDB (mongolab) from my local GAE server (localhost/8888). I am using morphia and my mongodb driver version is 2.4. My code looks like this:
Mongo m = new Mongo("xyz.mongolab.com",);
Datastore datastore = new Morphia().createDatastore(m, "staging","uname","password".toCharArray());
This throws the following exception :
com.mongodb.MongoInternalException: DBPort.findOne failed
at com.mongodb.DBPort.findOne(DBPort.java:153)
at com.mongodb.DBPort.runCommand(DBPort.java:159)
at com.mongodb.DBTCPConnector.testMaster(DBTCPConnector.java:371)
at com.mongodb.Mongo.(Mongo.java:167)
Caused by: java.io.IOException: couldn't connect to [xyz.mongolab.com/:] bc:java.net.SocketException: Operation failure: setSocketOptions: Not yet implemented
at com.mongodb.DBPort._open(DBPort.java:205)
Does somebody know why this is happening ?
it was a problem with using the old mongodb driver.. works after i upgraded..