public static Span createRemoteSpan(String name, Context ctx) {
    return getGlobalTracer().spanBuilder(name).setParent(ctx).setSpanKind(SpanKind.SERVER)
      .startSpan();
  }
Create a span which parent is from remote, i.e, passed through rpc.
</p>
We will set the kind of the returned span to {@link SpanKind#SERVER}, as this should be the top
most span at server side.
hbase-common/src/main/java/org/apache/hadoop/hbase/trace/TraceUtil.java