python - Opencensus Python gRPC 的“异常迭代请求”

Question

我正在尝试通过 gRPC 将 OpenCensus 跨度发送到使用 python 的 OpenCensus 收集器，如下所示：

from opencensus.proto.agent.trace.v1.trace_service_pb2 import ExportTraceServiceRequest
from opencensus.proto.agent.trace.v1.trace_service_pb2_grpc import TraceServiceStub
import grpc


def export(spans, endpoint):
    channel = grpc.insecure_channel(endpoint)
    client = TraceServiceStub(channel=channel)
    rq = ExportTraceServiceRequest(spans = spans)
    responses = client.Export(rq)
    print(list(responses))

该spans参数包含一个类型列表opencensus.proto.trace.v1.trace_pb2.Span。我希望这会将列表中的所有跨度导出到正在监听的 opencensus 收集器endpoint。但是，我没有看到任何数据到达并且响应对象包含

<_MultiThreadedRendezvous of RPC that terminated with:
    status = StatusCode.UNKNOWN
    details = "Exception iterating requests!"
    debug_error_string = "None"
>