Erlang: starting gen_server on another node fails after init - erlang

Question

I am stuck in a bit of a fix trying to run gen_server on another node. So I have a common gen_server class which looks like this
start(FileName) ->
start_link(node(), FileName).
start_link(ThisNode, FileName) ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [ThisNode, FileName], []).
init([ThisNode, FileName]) ->
process_flag(trap_exit, true),
{ok, Terms} = file:consult(FileName),
{A1, B1, C1} = lists:nth(1,Terms),
place_objects(A1, B1, C1).
Now I want to start multiple nodes that will run the same gen_server and somehow communicate with each other, and use a another node to orchestrate that. (All these nodes are started on my local terminal).
So I start a new node in one terminal using erl -sname bar where I intend to run the gen_server, and compile the gen_server module on this node. Then I start another node called 'sup' which I intend to use as a coordinator for all the other nodes. If I run the command my_gen_server:start("config_bar.txt"). on bar, it successfully returns but when I run the command rpc:call('bar#My-MacBook-Pro', my_gen_server, start, ["config_bar.txt"]). on sup, it successfully returns from the init method (I checked this by putting in the logs) but immediately after that, I get this error:
{ok,<9098.166.0>}
(sup#My-MacBook-Pro)2> =ERROR REPORT==== 21-Feb-2022::11:12:30.443051 ===
** Generic server my_gen_server terminating
** Last message in was {'EXIT',<9098.165.0>,
{#Ref<0.3564861827.2990800899.137513>,return,
{ok,<9098.166.0>}}}
** When Server state == {10,10,#Ref<9098.1313723616.3973185546.82660>,
'bar#My-MacBook-Pro'}
** Reason for termination ==
** {#Ref<0.3564861827.2990800899.137513>,return,{ok,<9098.166.0>}}
=CRASH REPORT==== 21-Feb-2022::11:12:30.443074 ===
crasher:
initial call: my_gen_server:init/1
pid: <9098.166.0>
registered_name: my_gen_server
exception exit: {#Ref<0.3564861827.2990800899.137513>,return,
{ok,<9098.166.0>}}
in function gen_server:decode_msg/9 (gen_server.erl, line 481)
ancestors: [<9098.165.0>]
message_queue_len: 0
messages: []
links: []
dictionary: []
trap_exit: true
status: running
heap_size: 1598
stack_size: 29
reductions: 3483
neighbours:
I can't seem to figure out what causes the error and if there's anything I need to add to my gen_server code to fix it. Would really appreciate some help on this one!

Answer 1

The gen_server in the remote node is linked to an ephemeral process created for the rpc call.
As this ephemeral process exits with a term that's different from normal (the actual result of the rpc call), the exit signal propagates to the gen_server, killing it.
You can use gen_server:start instead of gen_server:start_link or, if you want the gen_server to be part of the supervission tree, instruct its supervisor to spawn it:
rpc:call('bar#My-MacBook-Pro', my_gen_sup, start_child, ["config_bar.txt"]).