Is IProducer.ProduceAsync(...) thread safe?

Description

Is it safe to re-use an instance of IProducer to call ProduceAsync() from multiple threads?

My use case is an API method in an ASP.NET core application, in which I want to produce a message when the API is called.

How to reproduce

[Route( "api/demo/producer" )]
[ApiController]
public class ProducerController : ControllerBase
{
    private readonly IProducer<int, string> _kafkaProducer;

    public ProducerController( IProducer<int, string> kafkaProducer )
    {
        _kafkaProducer = kafkaProducer;
    }

    [HttpPost( "produce" )]
    public async Task<string> Produce( [FromBody] int key, [FromBody] string value )
    {
        var message = new Message<int, string> { Key = key, Value = value };
        var result = await _kafkaProducer.ProduceAsync( "test-topic", message );
        return $"Delivered '{result.Key}','{result.Value}' to '{result.TopicPartitionOffset}'";
    }
}

where the producer instance is injected as a singleton by adding it as a singleton in ConfigureServices() like this:

services.AddSingleton( new ProducerBuilder<int, string> ( config ).Build( ) );

Checklist

Please provide the following information:

• A complete (i.e. we can run it), minimal program demonstrating the problem. No need to supply a project file.
• Confluent.Kafka nuget version.
• Apache Kafka version.
• Client configuration.
• Operating system.
• Provide logs (with “debug” : “…” as necessary in configuration).
• Provide broker log excerpts.
• Critical issue.

[mhowlett]

yes, our documentation is badly lacking. it’s on the list.

[mhowlett]

yes