OpenTracing documentation Client Server

[jek-bao-choo]

Does anyone have OpenTracing documentation on how to inject context at client and extract context at server?

The golang of nats has a documentation example. Wondering if we have one for nats.net?

If anyone of you have it, please share. I am happy to do PR to add it to the README.md here.

[jek-bao-choo]

I got the client / publisher side of code working

         using (IScope scope = tracer.BuildSpan("MyPublisherSpan")
                        .WithTag(Tags.SpanKind.Key, Tags.SpanKindProducer)
                        .WithTag(Tags.Component.Key, "nats-example-producer")
                        .StartActive(finishSpanOnDispose: true))
                    {
                        var span = scope.Span;
                        span.SetTag("MyTag", "MyValue");
                        span.Log("My Log Statement");
                        Dictionary<string, string> contextPropagationKeyValuePairs = new Dictionary<string, string>();
                        tracer.Inject(scope.Span.Context, BuiltinFormats.TextMap, new TextMapInjectAdapter(contextPropagationKeyValuePairs)); // ref https://github.com/opentracing/opentracing-csharp/tree/master/examples/OpenTracing.Examples
                        if (contextPropagationKeyValuePairs.ContainsKey("traceparent"))
                        {
                            var traceparent = contextPropagationKeyValuePairs["traceparent"];
                            Console.WriteLine("**********publisher W3C traceparent ------> {0}", traceparent);
                            payload = Encoding.UTF8.GetBytes(traceparent);
                            Console.WriteLine("**********publisher encoded payload");
                            foreach (byte element in payload)
                            {
                                Console.WriteLine("{0} = {1}", (char)element, element);
                            }
                        }

                        //foreach (KeyValuePair<string, string> kvp in contextPropagationKeyValuePairs)
                        //{
                        //    Console.WriteLine("**********publisher testKeyValuePairs v2 ------> ");
                        //    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
                        //}

                    }

                    c.Publish(subject, payload);

Going to work on the server / subscriber side.

[jek-bao-choo]

For subscriber will be this

                  Console.WriteLine("*******AsyncReceived = {0} ", args.Message);
                    Console.WriteLine("*******args.Message.Subject = {0} ", args.Message.Subject);
                    Console.WriteLine("*******args.Message.Data = {0} ", args.Message.Data);

                    var payload = args.Message.Data;
                    //foreach (byte element in payload)
                    //{
                    //    Console.WriteLine("{0} = {1}", (char)element, element);
                    //}
                    var traceparent = Encoding.UTF8.GetString(payload);
                    Console.WriteLine("**********subscriber W3C traceparent ------> {0}", traceparent);

                    Dictionary<string, string> contextPropagationKeyValuePairs = new Dictionary<string, string>();
                    contextPropagationKeyValuePairs.Add("traceparent", traceparent);

                    //foreach (KeyValuePair<string, string> kvp in contextPropagationKeyValuePairs)
                    //{
                    //    Console.WriteLine("**********subscriber testKeyValuePairs v2 ------> ");
                    //    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
                    //}
                    ISpanContext context = tracer.Extract(BuiltinFormats.TextMap, new TextMapExtractAdapter(contextPropagationKeyValuePairs)); // ref https://github.com/opentracing/opentracing-csharp/tree/master/examples/OpenTracing.Examples
                    // todo: How do I set the topic to make the topic appears in APM service map?
                    using (IScope scope = tracer.BuildSpan("MySubscriberSpan")
                        .WithTag(Tags.SpanKind.Key, Tags.SpanKindConsumer)
                        .WithTag(Tags.Component.Key, "nats-example-consumer")
                        .AsChildOf(context)
                        .StartActive(finishSpanOnDispose: true))
                    {
                        var span = scope.Span;
                        span.SetTag("MyTag", "MyNatsSubscriberValue");
                        span.Log("My Nats Subscriber Log Statement");
                    }

This is for W3C header. Not B3 header.

[scottf]

@jek-bao-choo I'm not understanding what you are trying to accomplish here! What documentation in the NATS go client are you referring to (maybe a link to github?). What "context" are your referring to and what client/server to you mean read and inject from. Please give more information so I can help you.

[scottf]

@jek-bao-choo converted to discussion

[ColinSullivan1]

We currently have a java reference for using Open Tracing - although it is dated and was written before we had headers, and so we used a binary carrier.

https://github.com/nats-io/not.java

I think this is a great idea - a .NET version of that reference architecture that uses the textMap carrier utilizing NATS headers. That being said, I think it would reside in be a separate repo + package rather than being here in NATS.Client assembly.