Messages getting lost in Confluent Kafka Dotnet

Question

I am using Confluent kafka package in my recent c# project. I created a producer in the following way:

prodConfig = new ProducerConfig { BootstrapServers = "xxx.xxx.xxx.xxx:xxx"};

foreach(msg in msglist){
    using(var producer = new ProducerBuilder<Null, string>(prodConfig).Build()){
        producer.ProduceAsync(topic, new Message<Null, string> {Value = msg});
    }
}

But the issue is that some of my messages are not getting to the consumer. They are getting lost somewhere. However, if I use await with the producer then all the messages are getting delivered. How to deliver all my messages without await. (I have a single partition)

Answer 1

First of all, you should use only a single Producer to send your msgList, because creating a new Producer for each message is really expensive.

What you could do, is use Produce() method with Flush(). With Produce() you will send messages asynchronously without waiting for a response. And then calling a Flush() will block until all in-flight messages are delivered.

var prodConfig = new ProducerConfig { BootstrapServers = "xxx.xxx.xxx.xxx:xxx"};
using var producer = new ProducerBuilder<Null, string>(prodConfig).Build();

foreach (var msg in msglist)
{
    producer.Produce(topic, new Message<Null, string> { Value = msg });
}

producer.Flush();

---

Without await or Flush() you might lose messages because your producer might be disposed before all the messages are delivered.