in geronimo-opentracing-extension/src/main/java/org/apache/geronimo/opentracing/extension/proxy/TracingProxyFactory.java [124:132]
private void onError(final Scope scope, final Throwable e) {
final Span span = scope.span();
Tags.ERROR.set(span, true);
final Map<String, Object> logs = new LinkedHashMap<>();
logs.put("event", Tags.ERROR.getKey());
logs.put("error.object", e);
span.log(logs);
}