gen_server stands for "generic server", a module behaviour in Erlang.
Questions tagged [gen-server]
315 questions
0
votes
1 answer
Phoenix application on a fleet of machines
I'm developing a real-time Phoenix App using it's Channel and Socket modules. The App consists of a few processes and GenServers. I have a use case, where on an event (which is an API call from a microservice), I need to broadcast messages to all…
Rahul Sharma
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votes
1 answer
Understanding Genserver - start_link/0 conflicts with default
I'm trying implement a GenServer to monitor one of my functions and then restart the process after 1 hour. Forgive the lack of knowledge as this if my first experience with GenServer.
CODE:
defmodule Statcasters.Scheduler do
use GenServer
use…
Bitwise
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Why doesn't my GenServer handle_cast get called
I am using GenServer in my module as below. In the init method, it creates a redis connection to the database. The put method will send values to be saved in redisdb. The handle_cast method will call the command on redis connection to do the…
Joey Yi Zhao
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Ecto changesets and GenServers using TDD
I'm testing a GenServer by unit testing the handle_{call,cast,info} callbacks. One of my doctests is as follows:
@doc """
Call the GenServer to retrieve…
category
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GenStage: retry handle_demand when GenServer updates
If my GenStage's handle_demand/2 method looks like this:
def handle_demand(demand, _state) when demand > 0 do
case Queue.dequeue do
nil ->
Logger.debug("Queue empty.")
{:noreply, [], []}
{job, updated_queue} -> {:noreply, job,…
t56k
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0
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1 answer
Elixir: Loop the actor to rerun itself
I am making an master-worker application. The Master code is as follows. This code asynchronously calls workers in start_link. Once the workers are done with their work, they report to master using handle_cast asynchronous call. After this I intend…
Prince Bhatti
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Test an Elixir Monitor Process for Phoenix Channel Close without a timer delay?
I currently have functionality which tracks when a user connects to a channel and when a user leaves a channel. This is implemented from this stackoverflow answer here.
I have written the following test (see commit) to verify my callback…
Alexander
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0
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1 answer
gen_server stop badmatch on sub process stopped
I have a table process which creates a pidfor a board as part of its state with go().
I am testing that terminating the table also terminates the board. But the board is not stopping as expected.
My test:
kills_board_test() ->
{ok, Table} =…
quantumpotato
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How to spawn a Erlang process dynamically for one activity and kill it once activity done
There are many parallel requests coming to one erlang OTP (gen_server) process.
One process is not sufficient to handle this.
I can have fix number pool of same processes to handle this using Poolboy or worker_pool.
But I dont want to have fix set…
ManasP
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- 6
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bad argument in call to fxml_stream:new(undefined, 65536)
I am not familiar with erlang and new to ejabberd. I am getting following
error in crash.log.
2017-06-22 04:58:53 =CRASH REPORT====
crasher:
initial call: ejabberd_receiver:init/1
pid: <0.23584.370>
registered_name: []
exception exit:…
Khadija
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- 5
0
votes
1 answer
Task.await timeout which is causing GenServer to terminate
My Genserver terminates after a little while, after sending a few http requests. I can't understand the reason:
[error] GenServer MyGenServer terminating
** (stop) exited in: Task.await(%Task{owner: #PID<0.420.0>, pid: #PID<0.1054.0>, ref:…
Jodimoro
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Why do I get twice the same message?
I'm quite new in Erlang, and I'm developing a little program to simulate a robot which collect cans:
-export([start/0]).
start()->
Believes=#{bin_position=>0, num_cans=>1, can_position=>4, my_position=>1},
PID=spawn(fun()->…
Antolinos95
- 57
- 7
0
votes
1 answer
GenServer and its state
I this this simple genserver:
def handle_info(:tick, items) do
items2 = do_job(items)
tick()
{:noreply, items2}
end
In "do_job" I need to a) iterate throug items, b) make an http request which can take long and c) depending on a response,…
user7905648
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- 6
0
votes
1 answer
gen_server:call - how to send message
Now Im playing with the gen_server
I have two modules - one is Gen Server mod, second - logic module
and would like to send the message to the PID through the gen_server:call
here is the snip of code:
lookup_by_date(FromTime, ToTime) ->
…
Eugen Dubrovin
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0
votes
3 answers
gen_server run slower when mailbox get bigger
I've got a problem, I use gen server to do some simple work like this:
one handle_cast to do a long time work(takes 60 seconds)
one handle_cast to do a very fast work
everything is fine when traffic is low. But when the server process is…
蛋汤饭
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