Custom sampler using javaagent

[bgong-mdsol]

I am using java agent with a custom sampler which can decide sampling the Internal span or not based on a condition, see below:

public class MySampler implements Sampler {

final static boolean isDisableInternalSpan = disableInternalSpan();
 ...

  @Override
  public SamplingResult shouldSample(Context parentContext, String traceId, String name,
      SpanKind spanKind, Attributes attributes, List<LinkData> parentLinks) {
    SpanContext parentSpanContext = Span.fromContext(parentContext).getSpanContext();
    if (spanKind.equals(SpanKind.INTERNAL) && isDisableInternalSpan) {
      return SamplingResult.create(SamplingDecision.DROP);
    } else {
      return traceSampler.shouldSample(parentContext, traceId, name, spanKind, attributes, parentLinks);
    }
  }

...

}

It will drop the the Internal span and its child spans, is it possible to drop Internal span only, e.g
The trace tree: Server span -> internal span -> DB span
The expected tree without internal span: Server span -> DB span

[laurit]

Perhaps the traceSampler you delegate to is a parent based sampler that samples only when parent span was sampled?

[trask]

If you use a non-parent based sampler, you could capture the db span, but I don't think it would be parented to the server span anymore.

If you are looking to suppress INTERNAL spans produced by the standard javaagent instrumentation, most of those are suppressible using https://opentelemetry.io/docs/instrumentation/java/automatic/agent-config/#suppressing-controller-andor-view-spans