CODEWITHSUNDEEP
pythondjangogrpcdjango-serializergrpc-python
Hasan Gilani
Hasan Gilani

Reputation: 41

python gRPC error: "error": "13 INTERNAL: Failed to serialize response!" when trying to return a repeated message instead of stream in a List Request

I have django REST API that I am trying to convert into gRPC. I followed the Django grpc framework guide and created the following files:

models.py
class Organization(models.Model):
    Org_name = models.CharField(max_length=100, unique=True, primary_key=True, db_index=True)
    Address = models.CharField(max_length=100)
    Description = models.CharField(max_length=500)
    Number_of_emp = models.IntegerField()
org.proto

package org;

import "google/protobuf/empty.proto";

service OrganizationController {
    rpc List(OrganizationListRequest) returns (Organizations) {}
    rpc Create(Organization) returns (Organization) {}
    rpc Retrieve(OrganizationRetrieveRequest) returns (Organization) {}
    rpc Update(Organization) returns (Organization) {}
    rpc Destroy(Organization) returns (google.protobuf.Empty) {}
}

message Organization {
    string Org_name = 1;
    string Address = 2;
    string Description = 3;
    int32 Number_of_emp = 4;
}

message OrganizationListRequest {
}

message OrganizationRetrieveRequest {
    string Org_name = 1;
}

message Organizations {
    repeated Organization organization = 1;
}

Note that Organizations is a message declared in org.proto to return a List or an array of objects

services.py
class OrganizationService(generics.ModelService):
    queryset = Organization.objects.all()
    serializer_class = OrganizationSerializerProto
serializers.py
class OrganizationSerializerProto(proto_serializers.ModelProtoSerializer):
    class Meta:
        model = Organization
        proto_class = org_pb2.Organization
        fields = '__all__'

Problem I want to make a request using the rpc List(OrganizationListRequest) returns (Organizations) {} to fetch a list of all the organization in the database. However, whenever I make a call to the rpc, I get the following error: request error: "error": "13 INTERNAL: Failed to serialize response!" (I use the BloomRPC gui client to make the request)

However, If I change
rpc List(OrganizationListRequest) returns (Organizations) {} to
rpc List(OrganizationListRequest) returns (stream Organization) {}
the request returns works fine and I get a stream of response of containing allobjects. I do not want to return data in streams, I want it to return an array of objects, but using message Organizations {repeated Organization organization = 1;} throws the above error. Am I making a mistake? I searched everywhere but I couldn't find this error. Or is it not possible to make an RPC call like this?

Upvotes: 4

Views: 13677

Answers (1)

Lidi Zheng
Lidi Zheng

Reputation: 2091

This is a server-side proto codec error. It usually happen because of:

  1. Inconsistent generated proto library between client/server;
  2. Type mismatch message (like sent Organizations instead of Organization).

gRPC Python will log the exception that is causing the Failed to serialize response! error. You can enable Python logging explicitly via logging.basicConfig(level=logging.INFO). Here is the link to the logging line:

https://github.com/grpc/grpc/blob/bed585bdcb5cbbbfb407b4e869665d405b04adca/src/python/grpcio/grpc/_common.py#L88

If after above examination, the error still persist, can you create a reproduce case and send to https://github.com/grpc/grpc/issues?

Upvotes: 6

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