@Bean ArmeriaServerConfigurator grpcCollectorConfigurator(StorageComponent storage,
    CollectorSampler sampler, CollectorMetrics metrics) {
    CollectorMetrics grpcMetrics = metrics.forTransport("grpc");
    Collector collector = Collector.newBuilder(getClass())
      .storage(storage)
      .sampler(sampler)
      .metrics(grpcMetrics)
      .build();

    return sb ->
      sb.service("/zipkin.proto3.SpanService/Report", new SpanService(collector, grpcMetrics));
  }
Collector for receiving spans on a gRPC endpoint.
zipkin-server/src/main/java/zipkin2/server/internal/ZipkinGrpcCollector.java