UnaryStream fails with GRPC.RPCError: timeout waiting for server

[heath-hh]

Hey! 👋 I've been using your library a bit, and I happened on an error with streams. I'm wondering if maybe the received gun_data might have what I'm looking for or if the server isn't receiving a response.

I don't know it's the grpc library or the way I'm using it, but I could use a little guidance. Here's all the relevant information:

The Test Failure

$ mix test test/ledger_grpc_test.exs
received a msg: {:gun_data, #PID<0.203.0>, #Reference<0.1984767090.2531262471.251349>, :nofin, <<0, 0, 0, 0, 3, 10, 1, 48>>}
received a msg: {:gun_trailers, #PID<0.203.0>, #Reference<0.1984767090.2531262471.251349>, [{"grpc-status", "0"}]}


  1) test list_active_contracts/1 with valid data lists all active contracts (Ledger.GrpcTest)
     test/ledger_grpc_test.exs:99
     ** (FunctionClauseError) no function clause matching in anonymous fn/1 in Ledger.GrpcTest."test list_active_contracts/1 with valid data lists all active contracts"/1

     The following arguments were given to anonymous fn/1 in Ledger.GrpcTest."test list_active_contracts/1 with valid data lists all active contracts"/1:

         # 1
         {:error, %GRPC.RPCError{message: "timeout when waiting for server", status: 4}}

     code: replies = Enum.each(reply_enum, fn {:ok, reply} -> IO.inspect(reply) end)
     stacktrace:
       test/ledger_grpc_test.exs:120: anonymous fn/1 in Ledger.GrpcTest."test list_active_contracts/1 with valid data lists all active contracts"/1
       (elixir) lib/enum.ex:789: anonymous fn/3 in Enum.each/2
       (elixir) lib/enum.ex:3023: anonymous fn/3 in Enum.each/2
       (elixir) lib/stream.ex:1514: Stream.do_unfold/4
       (elixir) lib/enum.ex:3023: Enum.each/2
       test/ledger_grpc_test.exs:120: (test)



Finished in 20.0 seconds
1 test, 1 failure

Randomized with seed 3781

The Test:

 # test

 test "list_active_contracts/1 with valid data lists all active contracts", %{
  ledger_info: ledger_info
} do
  options = %LedgerApi.GetActiveContractsRequest{
    ledger_id: ledger_info.ledger_id,
    filter: %LedgerApi.TransactionFilter{
      filters_by_party: %{
        "insurance" => %LedgerApi.Filters{
          inclusive: nil
        }
      }
    },
    verbose: true,
    trace_context: nil
  }

  reply_enum = Ledger.Grpc.list_active_contracts(options)
  replies = Enum.each(reply_enum, fn {:ok, reply} -> IO.inspect(reply) end)
end

The library functions being called:

# client api

def list_active_contracts(options),
  do: GenServer.call(__MODULE__, {:list_active_contracts, options}, :infinity)



# server api

@impl true
def handle_call({:list_active_contracts, options}, _pid, ledger_info) do

  {:ok, stream} =
    ledger_info.channel
    |> LedgerApi.ActiveContractsService.Stub.get_active_contracts(options)

  {:reply, stream, ledger_info}
end



# extra logging

@impl true
def handle_info(msg, ledger_state) do
    _ ->
      IO.puts("received a msg: #{inspect(msg)}")
  end

  {:noreply, ledger_state}
end

The grpc server's log:

Serving an Active Contracts request...
Call 2: Buffered demand event from gRPC downstream.
Call 2: RS upstream subscription registered. Setting up onCancelHandler and onReadyHandler handlers.
Call 2: Flushing demand event to RS upstream.
Call 2: gRPC downstream is ready. Demanding new response from RS upstream.
Call 2: RS upstream emitted response message GetActiveContractsResponse(0,,List(),None).
Call 2: RS upstream completed.
[id: 0xfaf2d4ac, L:/127.0.0.1:6865 - R:/127.0.0.1:56274] OUTBOUND HEADERS: streamId=5 headers=GrpcHttp2OutboundHeaders[:status: 200, content-type: application/grpc, grpc-encoding: identity, grpc-accept-encoding: gzip] streamDependency=0 weight=16 exclusive=false padding=0 endStream=false
Call 2: gRPC downstream is ready. Demanding new response from RS upstream.
[id: 0xfaf2d4ac, L:/127.0.0.1:6865 - R:/127.0.0.1:56274] OUTBOUND DATA: streamId=5 padding=0 endStream=false length=8 bytes=00000000030a0130
[id: 0xfaf2d4ac, L:/127.0.0.1:6865 - R:/127.0.0.1:56274] OUTBOUND HEADERS: streamId=5 headers=GrpcHttp2OutboundHeaders[grpc-status: 0] streamDependency=0 weight=16 exclusive=false padding=0 endStream=true

[tony612]

Could you try master/0.5.0-beta? I updated gun/cowboy recently.

[polvalente]

Closing due to updates in #224. If the problem persists, we can reopen this issue