CODEWITHSUNDEEP
erlangerlang-shell
obvionaoe
obvionaoe

Reputation: 136

Client and server don't communicate if spawned on separate Eshell?

I have these 2 Erlang modules:

Server:

-module(server).

-export([start/0, loop/0]).

books(Cc) ->
  string:concat("Works ", Cc).

loans(Name) ->
  string:concat("Works too ", Name).

loop() ->
  receive
    {ClientPID, books, Info} ->
      ClientPID ! books(Info),
      loop();
    {ClientPID, loans, Info} ->
      ClientPID ! loans(Info),
      loop();
    _ ->
      io:fwrite("Invalid request received!~n"),
      loop()
  end.


start() ->
  spawn(server, loop, []).

and Client:

-module(client).

-export([start/1, client/1]).

start(Server_Address) ->
  spawn(client, client, [Server_Address]).

client(Server_Address) ->
  Server_Address ! {self(), books, "potato"},
  receive
    Response ->
      io:format("CLIENT ~w: ~w~n", [self(), Response])
  end.

I call Pid = server:start() it gives me a correct Pid without any errors, but when I call either client:start(Pid) or client:client(Pid) in a different Eshell it just doesn't communicate(It works if called in the same Eshell, obviously).

I know I'm just doing something wrong, but what is it? Thanks

Upvotes: 0

Views: 63

Answers (1)

José M
José M

Reputation: 3509

Most likely both nodes are not clustered, you may check which nodes belong to the cluster with nodes()

In order to start nodes that are reachable, you must name them:

erl -sname client@localhost

and ping the other node:

$> erl -sname server@localhost                   
Erlang/OTP 23 [erts-11.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1]

Eshell V11.1  (abort with ^G)
(server@localhost)1> nodes().
[]
(server@localhost)2> net_adm:ping('client@localhost').
pong
(server@localhost)3> nodes().                         
[client@localhost]

Upvotes: 2

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