does kafka support dotnet core? - apache-kafka

Question

I'm trying to make a Kafka producer and consumer, but my project is in dotnet Core 2.0 and it doesn't seem to work well with kafka. This is the proof-of-concept I've tried coming up with. I'm using Visual Studio 2017 with the kafka-net nuget package:
using
using KafkaNet;
using KafkaNet.Model;
using KafkaNet.Protocol;
producer
static void Main(string[] args)
{
string payload = "Welcome to Kafka!";
string topic = "IDGTestTopic";
Message msg = new Message(payload);
Uri uri = new Uri("localhost:9092");
var options = new KafkaOptions(uri);
var router = new BrokerRouter(options);
var client = new Producer(router);
client.SendMessageAsync(topic, new List<Message> { msg }).Wait();
Console.ReadLine();
}
consumer
static void Main(string[] args)
{
string topic = "IDGTestTopic";
Uri uri = new Uri("http://localhost:9092");
var options = new KafkaOptions(uri);
var router = new BrokerRouter(options);
var consumer = new Consumer(new ConsumerOptions(topic, router));
foreach (var message in consumer.Consume())
{
Console.WriteLine(Encoding.UTF8.GetString(message.Value));
}
Console.ReadLine();
}
When I try to run the producer first, I get an error message on the BrokerRouter:
$exception {System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: port
at System.Net.IPEndPoint..ctor(IPAddress address, Int32 port)
at KafkaNet.DefaultKafkaConnectionFactory.Resolve(Uri kafkaAddress, IKafkaLog log)
at KafkaNet.Model.KafkaOptions.<get_KafkaServerEndpoints>d__0.MoveNext()
at KafkaNet.BrokerRouter..ctor(KafkaOptions kafkaOptions)
at SampleKafkaProducer.Program.Main(String[] args) in C:\v4target\SampleKafka\SampleKafkaProducer\SampleKafkaProducer\Program.cs:line 18} System.ArgumentOutOfRangeException
How is a port of 9092 out of range? My Visual Studio projects are running on ports in the 55000's. Multiple sources I've researched use 9092 as a kafka port.
Does anyone understand the error message? Is part of the main problem because I'm using a version of Kafka not compatible with dotnet core?

Answer 1

The problem is with the uri.
Uri uri = new Uri("localhost:9092");
If you print out the uri.Port, it's -1. Hence the ArgumentOutOfRangeException.
Try this instead:
Uri uri = new Uri("http://localhost:9092");
From the KafkaNet Repository. This is how they setup the URI:
var options = new KafkaOptions(new Uri("http://CSDKAFKA01:9092"), new Uri("http://CSDKAFKA02:9092"))
{
Log = new ConsoleLog()
};