Question - Creating custom spans in functions

I have just started to explore distributed tracing and have a question regarding this. I want to create a Span inside the parseDonutInfo() to trace the time taken to complete the function call. https://github.com/opentracing-contrib/java-opentracing-walkthrough/blob/master/microdonuts/src/main/java/com/otsample/api/ApiContextHandler.java#L85

In order to do that, I create a span -

try (Span parseDonutsInfoSpan =
                GlobalTracer.get().buildSpan("parseDonutsInfo_span")start()) {}

However, this span doesn’t get included along with the parent Span. It is present as a separate trace in Zipkin UI. How do I ensure that doPost function is the parentSpan of parseDonutsInfo().

Thanks, Let me know if you need any more details.

[jorgheymans]

AFAIU since the parent span was put as an attribute on the request in doPost (just before the call to parseDonutsInfo), you could just do this:

        static DonutRequest[] parseDonutsInfo(HttpServletRequest request)
            throws IOException
        {
            Span parentSpan = (Span) request.getAttribute("span");
            Span parseDonutsInfoSpan = GlobalTracer.get().buildSpan("parseDonutsInfo_span").asChildOf(parentSpan)
                .start();
          ... 
          parseDonutsInfoSpan.finish();

[iamsurya-dev]

Thanks for the comment @bhs ! It looks like https://github.com/opentracing-contrib/java-opentracing-walkthrough/pull/3 is using activeSpan(). I’ll also try it out from my end.