There is no way to set the service config on the gRPC server side. The name resolver has nothing to do with the gRPC server side; the name resolver is the component in the client that resolves a name into a set of addresses, so that the client knows what servers to connect to. For more information, see https://github.com/grpc/grpc/blob/master/doc/naming.md. The DNS resolver provides a way to get the service config from a TXT record, as described in https://github.com/grpc/proposal/blob/master/A2-service-configs-in-dns.md.
Alternatively, you can set GRPC_ARG_SERVICE_CONFIG directly on the client side. On Wed, Dec 13, 2023 at 10:10 AM D Dob <ober.ist.den...@gmail.com> wrote: > Thanks! I was under the impression that *GRPC_ARG_SERVICE_CONFIG *is > already including it to the name resolver. I was aware of the client side > configuration but it seems like its primary purpose is for > debugging/testing. How can I set it then on the server side. Does gRPC > provide API to interact with the name resolver? It's pretty hard to get > information about this topic, given my very limited knowledge about this > topic. > > best, > > . > On Tuesday 12 December 2023 at 22:28:03 UTC+1 Mark D. Roth wrote: > >> The service config is not sent by the gRPC server. It cannot be done >> that way, because the service config sets parameters that are needed on the >> client before the client has contacted any server. Instead, the service >> config is intended to be returned to the client via the name resolver. >> There is also a local API that you can use to have the client application >> set the default service config directly. >> >> For details, see >> https://github.com/grpc/grpc/blob/master/doc/service_config.md. >> >> On Monday, December 11, 2023 at 2:08:52 PM UTC-8 D Dob wrote: >> >>> Hey all, >>> >>> I'm having a hard time to set the service_config on my server side and >>> have it received by a client. I'm testing it in a small playground project >>> and am currently out of ideas in how to get this working. Rough project >>> setup and findings: >>> >>> OS: linux, gRPC: v.160, v.1.58 >>> >>> *Server:* >>> ~~~ >>> const auto serviceConfig = readFile("service_config.json"); >>> builder.AddChannelArgument(GRPC_ARG_SERVICE_CONFIG, *serviceConfig); >>> >>> *Client:* >>> >>> *~~~* >>> const auto channel = grpc::CreateChannel(Address.data(), >>> grpc::InsecureChannelCredentials()); >>> std::cout << std::format("Server config: \n{}\n", >>> channel->GetServiceConfigJSON()); >>> Client client(channel); >>> client.sstream(10); >>> >>> *Client c-ares logs:* >>> [polling resolver 0x55eb2c40a410] request complete >>> >>> [polling resolver 0x55eb2c40a410] returning result: addresses=<2 >>> addresses>, service_config=<null> >>> chand=0x55eb2c406d80: got resolver result >>> >>> chand=0x55eb2c406d80: resolver returned no service config. Using default >>> service config for channel. >>> chand=0x55eb2c406d80: using service config: "{}" >>> >>> As to my understanding setting it via *GRPC_ARG_SERVICE_CONFIG *should >>> be all it >>> takes. Logs from c-ares look fine in general but it still can't find the >>> service_config. I've been >>> playing around with various settings but no luck :( >>> >>> Didn't want to pollute the chat here: >>> client logs: https://pastebin.com/sFq8FyWa >>> server logs: https://pastebin.com/HA54iAAw >>> relevant code: https://pastebin.com/u6bigcAj >>> >>> Any help or pointer to an example/test would be greatly appreciated. >>> Maybe i've just not understood something >>> >>> best, >>> >>> Dennis >>> >> -- > You received this message because you are subscribed to the Google Groups " > grpc.io" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to grpc-io+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/grpc-io/b47716dd-4bec-4998-8d23-6857a794ca8an%40googlegroups.com > <https://groups.google.com/d/msgid/grpc-io/b47716dd-4bec-4998-8d23-6857a794ca8an%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- Mark D. Roth <r...@google.com> Software Engineer Google, Inc. -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/CAJgPXp7neviRC2QXBeTVSGGyDb5bEeE47vNW_XcL8oanp2ZOug%40mail.gmail.com.
