So I just got a new liveview deloyment, using Redis as the pubsub backend while I get cluster forming figured out. The first page render works fine, and there is a phx_join and phx_reply of rendered. After signing in with default phx.gen.auth behavior, I’m getting many phx_join messages sent but no phx_reply. Any idea why this might be?
What does the log of you phoenix app say?
The only error I have in my cloudwatch logs is this:
05:34:59.591 [error] Ranch listener AppWeb.Endpoint.HTTP had connection process started with :cowboy_clear:start_link/4 at #PID<0.3127.0> exit with reason: {:function_clause, [{WebSockAdapter.CowboyAdapter, :terminate, [{:crash, :error, :function_clause}, %{port: 80, scheme: "http", version: :"HTTP/1.1", path: "/live/websocket", host: "app.domain.com", peer: {{0, 0, 0, 0, 0, 65535, 44063, 6462}, 37060}, method: "GET", qs: "_csrf_token=FQJ-CHkAYWVEDy5BejkzQhItNCouEx43ERGNMF55sKcqWQQtzDehxJSP&_track_static%5B0%5D=https%3A%2F%2Fapp.domain.com%2Fassets%2Fapp-4d990432c83d65c7274ba6c2f26005e3.css%3Fvsn%3Dd&_track_static%5B1%5D=https%3A%2F%2Fapp.domain.com%2Fassets%2Fapp-a33e271c2b56bde39457fdd88e722922.js%3Fvsn%3Dd&_mounts=0&_live_referer=undefined&vsn=2.0.0"}, {Phoenix.LiveView.Socket, %{}, {%{channels: %{}, channels_inverse: %{}}, %Phoenix.Socket{assigns: %{}, channel: nil, channel_pid: nil, endpoint: AppWeb.Endpoint, handler: Phoenix.LiveView.Socket, id: "users_sessions:n66qO3JS6Pqw7v2Bcx6iwnQYTasR4SwhP8tDgaNs9cg=", joined: false, join_ref: nil, private: %{connect_info: %{session: %{"_csrf_token" => "PP9F4FTP7DM0-hb6hiQBVYMg", "live_socket_id" => "users_sessions:n66qO3JS6Pqw7v2Bcx6iwnQYTasR4SwhP8tDgaNs9cg=", "user_token" => <<159, 174, 170, 59, 114, 82, 232, 250, 176, 238, 253, 129, 115, 30, 162, 194, 116, 24, 77, 171, 17, 225, ...>>}}}, pubsub_server: [adapter: Phoenix.PubSub.Redis, name: App.PubSub, node_name: "node-0qw2do37A_U=", url: "redis://master.redacted.cache.amazonaws.com:6379", ssl: true], ref: nil, serializer: Phoenix.Socket.V2.JSONSerializer, topic: nil, transport: :websocket, transport_pid: nil}}}], [file: ~c"lib/websock_adapter/cowboy_adapter.ex", line: 52]}, {:cowboy_websocket, :handler_call, 6, [file: ~c"/app/deps/cowboy/src/cowboy_websocket.erl", line: 564]}, {:cowboy_http, :loop, 1, [file: ~c"/app/deps/cowboy/src/cowboy_http.erl", line: 253]}, {:proc_lib, :init_p_do_apply, 3, [file: ~c"proc_lib.erl", line: 241]}]}
Formatting that message helps make it understandable:
{
:function_clause,
[
{
WebSockAdapter.CowboyAdapter,
:terminate,
[
{:crash, :error, :function_clause},
%{
port: 80,
scheme: "http",
version: :"HTTP/1.1",
path: "/live/websocket",
host: "app.domain.com",
peer: {{0, 0, 0, 0, 0, 65535, 44063, 6462}, 37060},
method: "GET",
qs: "_csrf_token=FQJ-CHkAYWVEDy5BejkzQhItNCouEx43ERGNMF55sKcqWQQtzDehxJSP&_track_static%5B0%5D=https%3A%2F%2Fapp.domain.com%2Fassets%2Fapp-4d990432c83d65c7274ba6c2f26005e3.css%3Fvsn%3Dd&_track_static%5B1%5D=https%3A%2F%2Fapp.domain.com%2Fassets%2Fapp-a33e271c2b56bde39457fdd88e722922.js%3Fvsn%3Dd&_mounts=0&_live_referer=undefined&vsn=2.0.0"
},
{
Phoenix.LiveView.Socket,
%{},
{
%{channels: %{}, channels_inverse: %{}},
%Phoenix.Socket{
assigns: %{},
channel: nil,
channel_pid: nil,
endpoint: AppWeb.Endpoint,
handler: Phoenix.LiveView.Socket,
id: "users_sessions:n66qO3JS6Pqw7v2Bcx6iwnQYTasR4SwhP8tDgaNs9cg=",
joined: false,
join_ref: nil,
private: %{
connect_info: %{
session: %{
"_csrf_token" => "PP9F4FTP7DM0-hb6hiQBVYMg",
"live_socket_id" => "users_sessions:n66qO3JS6Pqw7v2Bcx6iwnQYTasR4SwhP8tDgaNs9cg=",
"user_token" => <<159, 174, 170, 59, 114, 82, 232, 250, 176, 238, 253, 129, 115, 30, 162, 194, 116, 24, 77, 171, 17, 225, ...>>
}
}
},
pubsub_server: [
adapter: Phoenix.PubSub.Redis,
name: App.PubSub,
node_name: "node-0qw2do37A_U=",
url: "redis://master.redacted.cache.amazonaws.com:6379",
ssl: true
],
ref: nil,
serializer: Phoenix.Socket.V2.JSONSerializer,
topic: nil,
transport: :websocket,
transport_pid: nil
}
}
}
],
[file: ~c"lib/websock_adapter/cowboy_adapter.ex", line: 52]
},
{:cowboy_websocket, :handler_call, 6, [file: ~c"/app/deps/cowboy/src/cowboy_websocket.erl", line: 564]},
{:cowboy_http, :loop, 1, [file: ~c"/app/deps/cowboy/src/cowboy_http.erl", line: 253]},
{:proc_lib, :init_p_do_apply, 3, [file: ~c"proc_lib.erl", line: 241]}
]
}
This tells us some things:
-
the ultimate cause of the exit was a
function_clauseerror inlib/websock_adapter/cowboy_adapter.ex:52 -
This error happened because
WebSockAdapter.CowboyAdapter.terminate/3only expects 2-tuples in the final argument, but the caller passed a 3-tuple shaped like{Phoenix.LiveView.Socket, %{}, {%{channels: ...}, %Phoenix.Socket{}}}The first element of that tuple is a handler like the module expects.
The third element is a
{state, socket}pair like would be expected withPhoenix.SocketThe second element is ???, and it’s going to be tricky to find where it came from
-
however, this isn’t the root cause - the process was trying to call
terminate/3because something else crashed with afunction_clause_error. Any noises in the logs before the message you posted?
My suspicion is a cascading error like this:
- something messed up the socket GenServer’s state from
{handler, state}to{handler, what_the_heck, state} - that caused the next function call dispatched against that server to fail to match (the first
function_clause_error) - that made the socket try to shut down, which then ALSO failed to match in
terminate/3(the secondfunction_clause_error)
2 Likes
Thank you! Do you know why it would be happening only after the user is authenticated? On the anonymous views I have, there doesn’t seem to be a problem. Seems like it’s crashing after the phx_join message, before it can respond.
What are you doing in the channel that may cause it to crash?
There’s nothing custom actually. The only thing non-default I can think of off the bat is that I’m using the Redis adapter for PubSub.
Can you show the code?
Sure, here’s the endpoint configuration in runtime.ex. As far as I can think at this point, there’s nothing else relating to sockets, pubsub, or presence in the app.
pubsub_server: [
adapter: Phoenix.PubSub.Redis,
name: App.PubSub,
node_name: "node-#{node_indentifier}",
url: redis_url,
ssl: true
]
Sorry, I was confused for a moment and thought it was an issue with channels.
I have never used the Redis adapter, nor have I needed to.
It works if you restore it to the original configuration?
May I ask though why you are using Redis?
You do not need it for PubSub to work.
And if you are worried about clustering, it is easy…
I wrote a post about it sometime back.
