Python客户端gRPC 'Socket closed'错误（grpc_status 14）求助

问题代码 #

def run():
    try:
        channel = grpc.insecure_channel('api-auth.uid.ir')
        stub = session_api_pb2_grpc.SessionServiceStub(channel)
        response = stub.RegisterUserSession(
            session_api_pb2.RegisterUserSessionRequest(
                context={'requestHeader': {}, 'appInfo': {}, 'apiInfo': {}, 'panelInfo': {}},
                user={
                    'businessInformation': {
                        'projectName': 'Direct',
                        'businessId': '**************************',
                        'businessToken': '**************************'
                    },
                    'userInformation': {
                        'nationalId': '0874534879',
                        'nationalIdSerial': '1234567',
                        'sex': 1
                    }}))

        print(response)
    except Exception as e:
        print(e)

报错信息 #

<_InactiveRpcError of RPC that terminated with:
    status = StatusCode.UNAVAILABLE
    details = "failed to connect to all addresses; last error: UNAVAILABLE: Socket closed"
    debug_error_string = "UNKNOWN:Failed to pick subchannel {created_time:"2022-11-02T10:50:26.638744+03:30", children:[UNKNOWN:failed to connect to all addresses; last error: UNAVAILABLE: Socket closed {grpc_status:14, created_time:"2022-11-02T10:50:26.638736+03:30"}]}"
>

排查与解决步骤 #

• 指定正确端口：grpc.insecure_channel默认使用50051端口，如果目标服务用的是其他端口，需要显式声明，比如grpc.insecure_channel('api-auth.uid.ir:8080')，先确认服务端对外暴露的端口信息。
• 测试网络连通性：用telnet api-auth.uid.ir 50051或nc -zv api-auth.uid.ir 50051验证端口是否可访问，若不通，大概率是防火墙拦截、内网限制或地区网络封锁导致，需要调整网络环境。
• 确认是否需要TLS加密：如果服务端要求加密连接，使用insecure_channel会直接失败，此时要切换为secure_channel并配置证书：

  import grpc
  from grpc import ssl_channel_credentials
  
  credentials = ssl_channel_credentials()
  channel = grpc.secure_channel('api-auth.uid.ir:443', credentials)
  

• 校验请求参数合法性：部分服务会因参数格式错误主动关闭连接，检查context、user内的字段是否完全匹配服务端protobuf定义，比如sex的取值范围、空字典是否被允许。
• 添加超时与调试日志：给channel设置连接超时，同时开启gRPC调试日志，便于定位问题：

  import logging
  logging.basicConfig()
  logging.getLogger('grpc').setLevel(logging.DEBUG)
  
  channel = grpc.insecure_channel(
      'api-auth.uid.ir',
      options=[
          ('grpc.connect_timeout_ms', 10000),
      ]
  )
  

内容的提问来源于stack exchange，提问作者sadng