Possible to switch/modify Sampler from instrumented code

[tobias-]

Is it possible to do something like this somehow? I tried the following, but can't get it to work, ie change Sampler.

    SdkTracerManagement globalTracerManagement = OpenTelemetrySdk.getGlobalTracerManagement()
    TraceConfig activeTraceConfig = globalTracerManagement.getActiveTraceConfig()
    Sampler oldSampler = activeTraceConfig.getSampler()
    TraceConfig newConfig = activeTraceConfig.toBuilder()
        .setSampler(
            new Sampler() {
                @Override
                SamplingResult shouldSample(Context ctx, String p1, String p2, Span.Kind p3, Attributes p4, List<SpanData.Link> p5) {
                    System.err.println("We are on " + Thread.currentThread().getName());
                    if (Thread.currentThread().getName().equals("ebean.heartBeat")) {
                        return SamplingResult.create(SamplingResult.Decision.DROP);
                    }
                    return oldSampler.shouldSample(ctx, p1, p2, p3, p4, p5);
                }

                @Override
                String getDescription() {
                    return "Special!";
                }
            }
        )
        .build()
    globalTracerManagement.updateActiveTraceConfig(newConfig)

[tobias-]

This is ofc related to a lot of issues which are similar, e.g. #2002 #1950 #1958 #1060

[tobias-]

The reason I thought this would work at all is because of io.opentelemetry.javaagent.instrumentation.opentelemetrysdk.OpenTelemetrySdkInstrumentation, but I didn't read it well enough..

It's just displays a "don't do this 'cause it won't work", that was hidden among the json-logged output